In the Field
Garden Club 5 May 2012
Eclipse 20 May 2012 Ukiah
Tree on my street
June 2012 Venus Transits the Sun Ukiah
June 2012 Car Show Santa Rosa
Macro (Close Up)
Objective or C-mount Lens
ASA or ISO Film Speed
Lab #02 Measure the Dynamic Range
Lab #1 f/16 Sunny Day Rule
Number of Pixels
Size of Pixels
Flash On Camera
Getting Image Out of
Possible Future Topics
Costco Photo Processing
Ukiah Area Photo Related
In some ways digital cameras are
very similar to film cameras and in other ways they are very
different. The idea here is to look at the basic things
required to get a good image.
An email to someone who was getting started:
1. In order to see into shadows what's called High Dynamic
Range (HDR) is what works. But rather than trying to do
this using stacking multiple exposures, just use RAW (.NEF in
the case of Nikon cameras) and set the bits per channel to the
highest possible value (14 bits for the D300s camera).
Note a .jpg has, by definition, 8 bits per color channel so 14
bits per color channel adds 6 full stops. When you
"develop" the RAW file in Photoshop there are sliders for
exposure and fill light (as well as color balance) since you
are getting all the information from the imaging chip, i.e.
the camera is not doing any image processing.
2. One cause of shadows is a light that's looks like a
point source, for example the sun. So instead you want a
very "flat" light source. If using a flash gun, use a
diffuser and/or aim it at the ceiling. I have a studio
flash with a 51" umbrella plus a diffuser setup next to a
3. Often the background can be a distraction from the main
subject. Before I got the light table, and even now with
it, I often use Photoshop to manually erase the background
). You will find this
very difficult if there is a black shadow next to a black
background, so this also is a learning experience in exposure
4. I've done "object removal stacking" as an experiment
so know it's works. So if you know about it and there's
people in some photos, you can take extra photos of the same
subject and erase them later.
5. A polarizing filter can eliminate some reflections.
6. There are a couple of things you can do to reduce
blur. If hand holding the camera use a short time delay
to release the shutter. I use 3 seconds. That way
there is no camera shake caused by the hand movement of
pressing the shutter. If you have a SLR and are doing
tripod supported close up photography use the mirror lock to
prevent "mirror flop".
The difference between a snap
shot and an artistic photograph has to do with all aspects of
the image. With film cameras there was a technical
challenge in getting a good exposure and with the focus on the
desired subject and not focus on the undesired
background. With the advent of modern digital cameras
the technical part can be overcome by knowing how to use the
camera, but the artistic part is up to the photographer.
I choose the photography classes at De Anza Jr. college that
were part of the Communications branch rather than the classes
at San Jose State that were part of the science branch.
The instructor (H.W. "Wick" Wichers) taught philosophy along
with photography which I liked. He told the story:
For years farmer Joe was
jealous of his neighbor Don. You see Don had a mule
that was worth his weight in gold because Don could get the
mule to do all kinds of hard work. Joe tried to buy the mule
for years but Don wouldn't sell. But one day Don
agreed and the mule had a new home. The next day Joe
shows up at Don's place complaining about how the mule would
not do anything, so they go back to Joe's field where the
mule is hooked up to a plow. Don picks up a 2x4 and
hits the mule up the side of his head and tells the mule to
pull and off goes the mule pulling the plow. Don says
to Joe, first you've got to get his attention.
So in photography you've got to put a 2x4 in the photo to
get the attention of the viewer. Without the 2x4 it's
just a snap shot.
This has to do with panning the camera up-down-left-right
zooming in-out and/or rotating the camera. There are
different ideas on how to do this. For example most
portraits in the U.S. are head shots where all of the head is
in the frame. In Europe it's common that the shot it
tighter cutting off part of the head.
Includes framing and also includes changing your point of
view, i.e. moving to somewhere else.
A common mistake when taking a portrait is having something in
the background that's distracting such as a telephone pole
coming out of the subjects head. Taking a few steps to
the left or right will eliminate the problem.
Subject Background Separation
Usually it's a good idea to
separate the subject from the background. There are
many ways of doing that.
By choosing the lens and f/stop it's possible to have the
subject in focus and the background out of focus.
Typically you want the lens wide open (Exposure
) this gives the smallest depth of field.
Picking a lens with good bokeh
important for many subjects.
The subject needs to be properly lit but the background can
be made to be either overexposed (high key photography) or
underexposed (low key photography). One of the
benefits of a photography studio is the ability to
independently light the subject and background. This
can be accomplished in the field by using flash lighting for
the subject or (more difficult) the background.
By simply moving the camera so that the background is either
lighter or darker or further away (more out of focus) the
subject background separation can be controlled.
Ken Rockwell starts off with the idea of FART before
taking a photograph
: You get a F
eeling that this is
something worthwhile as a subject for a photograph
sk yourself why this
would make a good photograph
efine the image to bring
out the quality that's attracted you
ake the photo
Then goes into what makes
a great photograph
Sex and Balance, You can never get too much
Ken Rockwell suggests that
because of how the human visual system (Ken:
How We See
) works the camera should be about 15 feet
from the subject. This means that a "portrait lens" (Ken:
) will be have a longer focal length than
was historically common. For example for head shots a
lens like the Nikon 300mm f/2.8 would be excellent.
This is an area where lens Bokeh (see below
The key is to set your camera
for the highest quality image (largest file size) AND use RAW,
.tif or any format other than jpg. Then look for even
flat lighting, not direct sun so that all of the subject is
illuminated and there are no harsh shadows. A room with
North facing windows at midday or best of all inside a white
tent. Let me do the background erasing. To make
that easier set the subject up on something like a short 2x4
or other spacer so any shadows are not right next to the
It's possible to take product photos without a studio.
The key is in erasing the background. In order for the
erasing to work the product needs to be illuminated in such
a way that there's not part of the product that is
underexposed and that is adjacent to undexposed background
since in that area you can not seperate the product from the
Note a small f/stop is needed to
get depth of field and the existing monolights do not
provide enough light so the image is underexposed.
|After correcting the
levels in Photoshop.
|After erasing the
In the Field
On 29 Aug 2011 there was a
motorcycle show in the Applebee's parking lot here in
Ukiah. I went knowing that the photographic problem
would be to separate the subject from the background. It
turned out that one of the motorcycles was one I had seen in
the magazines in the early 1970s and one was at the
show. I ended up taking dozens of photographs of this
one motorcycle. It later occurred to me that I should
have taken more photos of it and totally ignored all the other
motorcycles at the show. This example was in pristine
condition and very photogenic. There was no way to take
a photograph showing all of the motorcycle without also
getting a lot of clutter from the motorcycles that were to
it's left and right.
Thoughts after the show:
- Studying a single subject (motorcycle) in great detail
may result in better photographs than trying to cover the
- Using Active-D Lighting (High Dynamic Range HDR) may
have improved the images.
- Using a tripod and Mirror Up might have improved the
- Using stitching might have allowed a full image, but
it's doubtful that they would be at the same perspective.
- Asking the owner to move the motorcycle to separate it
from the other nearby bikes would have allowed better
- It may be that some of the same shots could have been
made by being, for example, more than twice as close and
taking a number of overlapping shots then stitching them
together. The advantage in doing this would be to
allow a poster-board print that was 20" x 30" that would
still have very fine detail. The 11" x 14"
poster prints had good detail, but might not if blown up
- Using A exposure mode and setting the f/stop to the
sweet range of F/8 to f/12 for the 105mm lens might have
resulted in sharper images.
For display on a wall an 8x10"
print is about the minimum size, 11x14, 16x20 or 20x30 are
much better. The problem is how to get very sharp images
that large. It takes some effort. The print sizes
shown below are based on 300 pixels per inch. This is
the print resolution needed for inspection from about
6". If a print will only bee seen from a much greater
distance then the resolution can be proportionally degraded.
If this is correct then stitching a number of images together
will be needed to get the required image resolution for large
(20 x 30) prints.
For a 30 x 20 print it would be best to use a 3x3 mosaic of
D300s images with some overlap for stitching
The problem with stitching (2x2, 3x3 above) is that the camera
needs to be moved in translation, not panning to avoid
distortion. There may be a way around this by using
Photoshop perspective correction, but it's not easy if it is
This is a term that means using a dot matrix printer for art
quality prints . For example the Epson
Stylus Pro 4900
uses 10 pigment inks and prints up to
Each dot can be any color, thre's no dithering like in a dot
matrix printer. That's to say it's a continuous-tone
technology, where each dot can be any color.
Computer Printers (Wiki)
The most common type is the gray scale laser printer that
works by fusing toner (very small black particles).
These use classical photographic chemical processes for the
negative and print (two separate machines). They are
fully automated and about the size of a chest type
freezer. The print size may be limited to 4x6 or
smaller, but some can do up to 8x12.
Required for decent results
- ISO 1000 (instead of the stock 200)
- Mirror Up release mode
- Noise Reduction (Nikon: Shooting Menu\Long Exposure
noise reduction: On)
- cable release
- moonless night
|Orion's belt, Nikon
300mm f/2.8 3 sec ISO 1000
Arri Tripod with Camera pointing opposite direction
& handle reversed.
|24 Sep 2011
D300s + 300mm f/2.8, Mirror Up, Manual exp f/2.8 3
sec, ISO 2000, Long Exposure Noise Reduction ON
Arri Tripod with legs as
short as they go (and rubber removed from top of QR
In this image you can see Jupiter and 3 moons.
There's a little streaking from star movement at 3
seconds and a lot of streaking for longer exposure
Need to try ISO 3200.
A Polar aligned star tracking mount would allow longer
exposures without star trails.
|The Sky6 sky map
showing the field of view of the Nikon D300s with the
300mm f/2.8 lens
Supplied by Paul.
24 Sep 2011 0313:53 PDT
Nikon D300s w/300mm lens
ISO 2000, 2 sec f/2.8
Note there is a small amount of star trailing at 2
|I saw a photo taken by
Chris Pugh that showed what looked like a daytime
scene, but it was taken at midnight on a moonless
The thing that was striking was there were stars in
the sky. he said it was a 30 second time
exposure. I had just been reading:
to Shoot the Night Sky (Introduction to
Astrophotography) where the Rule of 600 is
So if Chris used a 30 second exposure he must have
been using a 20mm lens. The photo at left was
done using a 17 mm FL.
|Rule of 600
Exposure of stars in order to avoid trails
is 600 / (Focal Length in mm).
30 seconds, F3.5, ISO 3200 Exp Comp +5, Long Exposure
Noise Reduction ON, Tripod
Why are there so many different
lens options? They have advantages when used for certain
types of photographs. The key parameters are: What
camera mounting, output image (chip) size (full frame FX or
half frame DX, or one of the newer fractional frame sizes),
Focal Length +(fixed or zoom), smallest and largest f/stop
(manual or automatic), focusing modes (manual, in camera
motor, in lens motor), Image Stabilization, ED glass, optical
transfer function (Wiki
weight, price, filter thread size, compatibility with cameras
(i.e. an older lens may need to be modified to be used on a
modern camera or will have limited functionality).
, Optical Lens
A normal 35mm film camera runs the film left to right and the
frame size is 24mm high x 36 mm wide. It's expensive to
make Full Size (FX) imaging chips that are that big and they
only appear on professional DSLR cameras. A more common
imaging chip for high end DSLR cameras is the half frame (DX)
size. If the view angle of a lens on a 35mm film camera
is X degrees, then when that lens is used on a DX type DSLR
the view angle will be X/2, i.e. it's as if a 2X tele-extender
was added to the lens.
Important Note: The aspect ratio of 35mm film is 2:3 or
1.5. This is different from 8x10 which is 4:5 or
1.25. So using an 8x10 aspect ratio print with a digital
camera image means you must crop (cut away some of the
image. That means that when shooting you need to know
that's going to happen or else you will end of cropping the
Early view cameras used 8"x10" film, probably
because the resolution of the first generation films
was much poorer than today's films. Later view
cameras and the Speed Graflex (Wiki)
press cameras used 4"x5" film. Note you get
four sheets of 4x5 film from a single sheet of 8x10
film, they have the same aspect ratio. In the
1960s every camera store stocked 4x5 film in a
selection of emulsions. Contact prints, which
can made without an enlarger, were common and so
came 8"x10" photographic printing paper. But
there is a disconnect between the aspect ratio of
8x10 paper and the image from a 35mm film camera or
today's DSLR cameras which have a 3:2 or 1.5 aspect
ratio. But there are 1.5 aspect ratio sizes:
4x6, 8x12, 12x18, 16x24 & 20x30.
When making a full size print from a Digital Camera (where the
most common aspect ratio is 1.5) requires a paper size with
the same aspect ratio. If some other aspect ratio is
used then part of the image is being thrown away. This
is OK for most things, except where high image resolution is
Common Print sizes in this ratio are (See Costc
below): 4x6, 8x12, 12x18, 16x24 (not from Costco), 20x30.
The Golden Ratio (Wiki
is an aspect ratio that's very pleasing to the human eye an is
1.618.... The DSLR (35mm film) aspect ratio of 1.5 comes
closer to the golden ratio than does the first generation
sheet film ratio of 1.25. So from an artistic
perspective using the newer aspect ratio paper sizes makes
This is a measure of the magnification of the lens. The
longer the focal length the closer the subject appears.
For a full frame (FX) 35mm film camera the "standard" 50mm
lens has a focal about equal to the diagonal of the frame
For a half frame (DX) digital camera a standard lens would be
A lens with a focal length less than the standard would be
called a wide angle lens and one with a longer than standard
focal length would be called a telephoto lens.
The focal length is the distance from the optical center of
the lens to the focal plane when the lens is focused on a
subject at infinity (very far away).
When a lens is focused at the closest possible subject it is
two focal lengths between the center and the subject and two
focal lengths between the center and the image, or four focal
lengths between the subject and it's image. Most normal
lens focus mechanisms do not have enough extension to do that
so extension tubes can be added between the lens and camera
body for close up work. The better close up extension
kits include a way to reverse the lens to improve it's optical
performance when used for close up work. A "close up" or
macro (Nikon: micro) lens has more focus travel and typically
a different optical design so it will work well when focused
on close subjects.
focusing distant trees
Focal Length 6.75"
Lens diameter: 2.75"
f number = 6.75"/2.75" = f/2.45
The D300s taking the photo is set at
1/5 sec & f/36.
|Paper with different
size holes labeled with f/number for the focal
length of the magnifying glass
|Mask added for f/4,
better focus than f/2.45 photo above.
|Mask added for f/5.6,
|Mask added for f/8
The ones with smaller f/stops are too dim.
|When a lens is
focused as close as possible to a subject it's 2 x
FL from subject to lens,
and 2 x FL from lens to image.
In this case it's about 13.5" from candle to lens
and about 13.5" from lens to image.
So to change the focus of a lens from infinity to
something closer you need to move
the lens away from the image plane. This is
why extender rings are used to move a lens
away from the image place for close up photography.
: For a non image (i) stabilization (vibration
reduction VS) lens the shutter speed should be faster than 1 /
(focal length in mm).
For example for a 105mm lens the shutter speed should be
faster than 1/100 sec. But with vibration reduction
turned on the shutter speed can be a stop or two slower, say
Note that the fastest possible shutter speed on many film
cameras was 1/500 sec. That meant that the longest
telephoto lens you could hand hold was 500mm. But
modern digital cameras now have shutter speeds that are a
number of stops faster. Nikon D300s to 1/8,000 and the
D60 to 1/4,000. That means you can hand hold a much
longer telephoto lens. The addition of image
stabilization adds to that. Some modern cameras have a
large optical zoom capability allowing extreme telephoto shots
while hand holding the camera, something a cold war spy only
could dream about.
How fast is that lens? The lens speed is a measure of
how much light it can gather. This is expressed by the
wide open f/stop of the lens. A classical glass lens
will have a typical speed for a given focal length, for
example 300mm and f/4. A more modern "Extra-low
Dispersion" (ED) lens designs uses one or more Fluoride glass
lens elements. They are a faster lens, for example 300mm
and f/2.8. They are also much more expensive. Some
film 35mm lenses were made as fast as f/0.9.
This is a lens property that has to do with how out of
focus areas of an image look. Nikon makes Defocus Control, or
DC lenses which allow manual adjustment of the spherical
aberration so that you can control bokeh. These
are NOT for getting a soft focus image, but rather to control
the out of focus background. They tend to be
pricey. I think only available in 105mm and 135mm focal
Aberration controllable optical system, Nikon Corp, Nov
24, 1998, 359/763
; 359/659; 359/764
Macro Lens System, Hoya Corp, May 11, 2010, 359/754
359/791 - a macro lens with controlled spherical aberration
Imaging optical system and apparatus using the same,
Olympus Corp, Sep 27, 2005, 359/771
; 359/772; 359/773
Optical resolution (Wiki
is a measure of how fine a detail the lens will show.
There are different ways to measure this, one is called
Modulation Transfer Function (Wiki
and another is a test chart (Wiki
(for example the ISO 12233 Test Chart).
There's a limit to resolution based on the diameter of the
objective (primary) lens. The larger the lens the higher
the resolution. So as a perfect lens is stopped down the
resolution will degrade. But most lenses are not made
perfectly and so have better resolution when stopped down 2 or
3 stops from full open. Note this is different than
depth of field where stopping down a lens causes increased
depth of field, but at the same time lowers resolution.
This is one of the reasons astronomical telescopes have such
large primary optics (typically a mirror) to separate stars
that are close together.
sharpness part 1: Introduction to resolution and MTF curves
by Norman Koren
ISO 12233 Chart Data and Sample Images
SLR and Lens Image Quality Comparison
-as you move the
mouse the arrow points to the right or left so you can compare
two lenses. I haven't checked all the other lenses but
the Nikon 300mm f/2.8
be the sharpest of them all.
For most lens designs there is a range of f/stops where the
lens performs best and that's in the middle of it's range of
f/stops. For example the Nikon 105mm Micro Nikkor has a
range of f/2.8 to f/36 but has the best resolution between f/8
The common way a camera lens is specified is by it's Focal
Length (FL) and f/stop, such as 300mm f/2.8.
To find the diameter divide the FL by the f/stop = 300 mm /
2.8 = 107.1 mm (divide by 25.4 to get inches) 107.1 /
25.4 = 4.22" lens diameter.
The diffraction limited resolution = (1.22 * wavelength) /
(lens diameter) [ all in the same units]
So there's a limit on how good a lens can be based on the
primary optic's diameter. But most lenses are not
diffraction limited. The typical lens has different
resolution for different f/stops and typically the center
f/stops are the best.
x 15.8 mm
x 15.8 mm
x 6.09 um
The angular optical resolution of a lens (Wiki
depends on the objective diameter.
dia D (FL/f) mm
Resolution (wide open) (SIN-1(671E-9/D)
Resolution (wide open) (0.671 * f) um
In astronomy the angular resolution is a measure of how well
you can see things like double stars. But the Earth's
atmosphere puts a limit on the "seeing" on the order of a
few arc seconds. Objective diameters less than or
equal to about 1 foot have an advantage because they are
looking through a smaller volume of air and so get more
clear viewing time. As the objective diameter gets
larger then there's more chance of turbulence somewhere in
the optical path.
Also in astronomy how faint a star you can see depends on
the usable area of the objective. For a lens the
usable area is the objective diameter. But for
reflecting telescopes that have a central obstruction you
need to subtract the obstruction's area from the objective
area to get the light gathering area.
Star spot size vs. f/number
The implication of this table is that for a diffraction
limited lens opened wide the spot size may be smaller than a
pixel, i.e. the lens is much better than the sensor.
But as the lens is stopped down, at f/8 for the two Nikon
cameras shown above, the spot size matches the pixel size so
the lens and sensor are balanced. More stopping down
will increase the spot size and degrade the image.
- has some lens
resolution Modulation Transfer Function (MTF) data
- has a lot of sample lens test chart photos
You can compare one lens to
itself at different f/stops. For example the 105mm
f/2.8 Macro lens is best when at f/8 - f/11 and not as
sharp at f/2.8.
Macro (Close Up)
A standard camera lens can only
focus as close as a foot to two so the scale of the recorded
image is much smaller than the subject. A macro (Nikon
calls them Micro) lens typically can make an image that's the
same size as the subject (a 1:1 ratio). True Micro photography
the image is larger than the subject. But with modern
digital cameras it's possible to take a macro image (i.e.
<= 1:1) and then display it on a computer screen and now
it's a micro image that's larger than life.
There are special considerations needed to take good macro
photographs such as flowers.
Microscope Objective or C-mount
Lens for Macro photography
Some of the focus stacking
images on the web of things like the eyes of a fly or other
insects it think are fantastic. In order to make those
images a microscope is typically used. But it seems
like a better option would be to adapt a microscope
objective (or a C-mount movie/TV camera lens) to the Nikon
and use the StackShot automated camera motion control. That
would eliminate the need for the microscope.
17 Oct 2011 - working on how to do this.
Telephoto photography has it's
own special considerations.
Extension Rings, Tele-Converters &
other Lens Related Accessories
The lowest cost cameras have a
fixed lens, i.e. there is no provision to focus. The
lens is preset to the hyperfocal distance (Wiki
distance called the focal length. The closest a subject
can be is twice the focal length of the lens and then the film
is also two focal lengths behind the lens. The range of
focus for most lens designs is typically not enough to get the
lens two focal lengths in front of the film and that's why
using extension rings between the camera body and lens allows
closer focusing for macro photography. When doing micro photography
is very close to the subject and the film/imaging chip is far
from the lens.
When the focus of a lens is adjusted the lens is moved back
and forth relative to the imaging chip. This changes the
magnification. The amount of magnification change is
very small if the subject is many many focal distances in
front of the lens. For example when using a 50mm lens to
take a photo of a subject that's 10 feet in front of the lens
the radio of object distance to lens FL is about 61 which is
much greater than 10.
But when doing macro photography where the subject to lens
distance is close to the lens focal length the change in
magnification is significant. This may be a problem if
you want to do focus stacking because the plate scale (Wiki
will be different for each image. To avoid that problem
when focus stacking the lens is not adjusted and the whole
camera is moved between exposures, hence the StackShot
Older cameras have a provision to add a diopter correction
lens to the viewfinder to correct for your eyes. Modern
cameras have an adjustment that allows making a correction for
your vision. I have my camera set so that no glasses are
worn when taking photos. When looking into the
viewfinder adjust the focus so that the non image features
(digital readouts, fiducial marks (Wiki
in the field of view) are in sharp focus. Then activate
the auto focus feature and now both the image and features
should all be in sharp focus.
Dominant Eye (Wiki)
Most people have a strong eye and a weaker eye. To
determine which of your eyes is dominant, with both eyes open
point you finger at some object then, without moving your
hand, use your left and right eye to view the scene by closing
one eye. With one eye the object will be lined up and
with the other eye it will not be lined up. When looking
through the camera viewfinder it's best to use your dominant
Pressing the shutter button is one of the most disruptive
things you can do in terms of moving the camera. That's
going to blur the image, so I'm putting this note under
Focus. For hand held shooting my standard self timer
setting is 3 seconds. So after pressing the shutter I
pay attention to framing and being still.
Most 35mm Single Lens Reflex cameras (Wiki: SLR
support the use of an interchangeable lens that contains a
means of focusing and setting the f/stop. It was common
to have a distance scale for focusing work against an index
mark. Adjacent to the index mark there were other depth
of focus (Wiki
index marks in different colors. Acceptable focus would
be obtained between the two depth of focus marks for the
|The Nikon lens Aperture
is set to f/22 and the focus is set so that infinity
is on the left yellow depth of field index. That
brings the best focus point to about 50 feet while the
depth of focus extends to 30 feet, i.e. it's set at
the hyperfocal distance.
Note that when set at f/11 (green depth of focus index
lines) the depth of focus is narrower (maybe infinity
to 50 feet) so for the maximum depth of focus you want
the smallest aperture setting (highest f/number).
When taking portraits where you want the background to
be out of focus setting the f/stop to the largest
aperture (smallest f/number) is the thing to do.
Also using a mild to strong telephoto lens helps to
separate the subject from the background in terms of
focus. This may cause parts of the head to be
out of focus, so normally you should focus on the
The method of focusing a digital SLR camera has changed
as they have evolved. Basically the camera body has a
computer that looks at how the image changes as the focus is
adjusted and sets the focus automatically. But, there
are times when it just does not work. For example if
there is not enough light or the scene does not have straight
lines running in the correct orientation, etc. In these
cases switching to manual focus is a solution. There are
number of different ways this is done that are covered by many
As the name implies, focus is done by manually turning the
focus ring on the lens.
This is the most common focus mode and is probably the
default mode for the camera. In single mode focus the
camera goes through the focus routine just once, typically
when the shutter is at the half pressed position. Some
Nikon cameras have a provision that will not allow an
exposure to be made if the camera thinks it's out of
focus. To get around this you can switch to Manual
When the shutter is half pressed the camera goes into
the focus routine and stays in the routine. The idea
is that as the subject moves the camera will follow
focus. For example when taking a macro photograph of a
flower that's being blown by wind single mode focus does not
work because the focus needs to dynamically follow the
flower, but using continuous mode solves that problem.
The early auto focusing was done
by means of a motor contained inside the camera body that
drove the focus mechanism in the lens. The advantage of
this method was lower lens cost since only one motor was
needed. But a disadvantage was that for a large lens the
time to focus was slower than you could get by using a larger
motor in the lens. The newer family of lenses has the
focus motor in the lens and they are faster and quieter than
the camera body focus motor system.
Depth of Field (=Depth of Focus)
A digital camera operates under
the same laws of optics (Wiki: optics
) as a film camera and there's a limit to the depth
of focus that can be obtained for a given exposure (see: hyperfocal
above). Cameras are
limited to what can be done in a single exposure to the
hyperfocal distance. Digital cameras can generate images
that have a much higher depth of field by taking a number of
images, all with the same settings including focus my moving
the camera, and then stacking the images (Wiki
Photography 201: Image Stacking
) using post processing
of those images in something like Photoshop. Note:
changing the focus changes the magnification making stacking
difficult to impossible.
The Depth Of Field (Wiki
can be decreased by opening the lens wide (small f number
like f/2.8) or can be increased by stopping down the lens
(high f number like f/36).
Lens Focal Length
When a longer focal length lens is used and the subject is
framed the same as when a shorter focal length lens is used
(i.e. you stand back with the longer lens) the depth of
field is less with the longer lens. This is why a
"Portrait" lens is typically 2 to 6 times the focal length
of a "Standard" lens.
This allows aiming the camera at the subject and setting and
locking focus. Then you can re-frame the scene so
the subject is no longer at the focus point in the
frame. On the Nikon D300s you can lock the focus by a
half press of the shutter.
See Mirror Up
under Release Modes.
Even though the 105mm lens has image stabilization (Vibration
Reduction VR in Nikon speak) there's a limit to what it can
accomplish. Even a tripod is not as stable as you would
desire. Some things that can be done to improve the
stability of a tripod are:
- lower and lock the crank up top extension
- collapse the legs to their shortest length
- lock down all the clamps
- use the camera's built in timer rather than a cable
release or the worse thing, pressing the shutter manually
There are some special considerations involved in close up
Most camera lenses will not
focus on a subject closer than a yard or more from the
camera. So a special "macro" lens is needed which
typically allow making the size of the image the same as the
size of the subject (1:1).
Depth of Focus
The depth of focus is very
shallow. There's a couple of ways of addressing this.
1. Stop down the lens. Many macro
lenses are capable of f/36 or smaller. This will
increase the depth of focus but presents two new problems.
a. It takes a lot of light
and/or a long exposure time when working at f/36. In
order to get light on a subject it's best to be using a
telephoto lens so the subject is not extremely close to
the front of the lens. For example when using the
105mm Nikon (they call it a Micro) lens the light from the
pop-up flash makes a shadow on the subject. So off
camera light is needed. When stopping down
that far (past f/5.6) the resolution of the lens is very
much degraded (see resolution
2. Use Focus Stacking (See Digital
Photography 201: Stacking
) The idea is to take a
number of exposures (on a tripod, mirror up) and then stack
the images in Photoshop or other focus stacking software to
improve the depth of focus. It's best to have the
camera in a manual mode for all functions (shutter speed,
f/stop, focus) and not change any of them during the
sequence of exposures. That means you should move the
camera rather than change the focus setting. The
reason is that changing the focus also changes the
magnification. That's why I got a Macro Focusing Rail.
||This is really two
rails that can be stacked. The idea is that in
addition to doing focus stacking you could also do
sticthing left to right, or they can be stacked so
both work in the same direction.
The large knob is connected to a pinion gear and and
there's a rack gear on the bottom of the unit.
The small knob controls the amount of friction, but
does not really lock the slide.
A Nickle coin works well for the 1/4-20 screw head
(top right of photo). Note this screw is too
long to be used on the Nikon D300s. Maybe if
the correct size washers can be found to install by
removing the screw and putting the washers between
the screw head and the slide (not between the slide
Showing the two units connected in the same
When a single unit is used the camera support
bracket is not on the center line and I don't see
how it can be changed to be on the center line since
the support bracket to rail mounting holes are a
In photography exposure is the
total amount of light that is allowed to reach the light
sensor either film or digital. It's the product of
brightness and time. The camera settings that control
the exposure are the f/stop and shutter speed.
The lowest cost cameras had a fixed shutter speed that
allowed correct exposure for a normal daytime scene when the
recommended film was used. For example the exposure for
a normal outdoor scene in direct sunlight is f/16 at 1/(ASA or
ISO film speed). For example for a film speed of 200
(ASA or ISO) the exposure would be f/16 at 1/200 of a second
Digital cameras replace the film with a Charge Coupled Device
or CMOS image sensor (Wiki:APS
sensor determines the quality of the resulting image.
The most common parameter that's advertised is the number of
Generally more is better and costs more.
ASA or ISO Film Speed
Film speed is a measure of a film's sensitivity to
light. Higher film speed numbers mean the film will
work better in dimmer light. The resolution of a film
is inversely proportional to it's film speed. For
example films used in the graphic arts where very fine
detail is needed have film speeds in the single
digits. Films for use in night photography may have a
film speed in the thousands but the resulting image has a
lot of grain structure. These are linear scales so an
ISO of 400 is twice as sensitive to light as an ISO of 200.
In digital cameras there is also noise at the higher film
speeds. For astronomical use (i.e. taking pictures of
mostly black) the Cannon digital SLRs have an advantage over
the Nikon digital SLRs because of how they handle black
images (dark frames in astronomy speak).
Exposure Value (Wiki)
This is a logarithmic way to express the exposure
(combination of f/stop and shutter speed). For example
EV 16 is equivalent to f/16 @ 1/125 (Wiki
range from EV -6 (f/16 @ 256 minutes) to EV 21 (f/16 @
1/8,000). Some cameras, like the Hasselblad (official page
, my comments
), have the
lens rings for f/stop and shutter speed locked together (you
need to pull them apart to change the EV) so that once set
any rotation of the combined ring is the same exposure
EV = Log2
(N*N/t) where N is the f/# and t is
shutter speed in seconds.
(X) = Loge(X)/Loge(2) = LN
Example: f/16 @ 1/200 sec
EV = LN(16*16/(1/200))
(2) = LN
In photography a "stop" is a
change in the exposure that either doubles or halves the
prior exposure. A sequence of f/stops that differ by
one stop is:
1.4, 2, 2.8, 4, 5.6, 8 11, 16, 22, 32, 45, 64, 90
these f-numbers are the ratio of the focal length of the
lens divided by the diameter of the entrance pupil.
The amount of light depends on the area of the lens that the
light can go through. Since the area of a circle is a
function of the square of the diameter the square root of 2
(or 1/2) shows up in the ratios called f/stops.
Note that alternate f/numbers double, for example:
Note that an exposure of f/16 at 1/200 sec is the same as an
exposure of f/22 at 1/100 sec. That's to say the image
sensor will receive the same amount of light for either of
The number of possible equivalent exposures that are
available depends on the limits on the lens possible
f/stops, the camera's possible shutter speeds and the
sensitivity of the image sensor (ISO number).
Also note that the light from a lamp falls off as the square
of the distance between the lamp and the subject. So
you can use the above f/numbers for the distance between the
lamp and subject. For example if you move a studio
light that was 5.6 feet from the subject to 11 feet the
light will be cut in half.
The last generation of film SLR cameras had digital metering
modes. One of the fantastic things about digital
exposure modes is that they can do things that took a lot of
effort to accomplish when manual control was used. The
metering modes are based on various types of light meters.
This is the same as it was on the early cameras. The
photographer sets the f/stop and shutter speed.
Metering is off.
A small spot, typically in the center of the frame, is
used to measure the light and set the exposure.
An area in the center of the frame, usually inside a
circle that's displayed in the viewfinder, is used to set
the exposure where the center gets more weight than the
outside of the circle. This mode mimics the way
early light meters worked.
A number of areas, in some manufacturer specific
arrangement, are used to analyze the image and decide on
the exposure. Typically this mode is required for
the camera to do most of it's high technology features.
Allows locking the exposure while the frame is aimed
somewhere and then moving the view somewhere else to make
This controls how the shutter
speed and f/stop are determined. It's different from
metering mode which relates to how the light is measured.
In this mode the camera sets both the f/stop and the
shutter speed. In the simplest case this amounts to
a Point-And-Shoot mode where no control by the
photographer is involved in the exposure.
P: Program Auto Exp
Tv: Shutter Time Value
Av: Aperture Value
AUTO1 - Point & Shoot (the flash
will automatically pop-up if needed)
P - Programmed
S - Shutter priority
A - Aperture priority
M - Manual shutter & aperture
Auto (Flash Off)1
|Nikon D60 (See
Nikon page D60
In this mode the f/stop and shutter are manually set.
Shutter Priority (S)
In this mode the photographer sets the shutter speed and
the light metering sets the f/stop.
In this mode the photographer sets the f/stop and the
light metering sets the shutter speed.
|These statues are in
front of a house and shaded by large trees.
There's two ways to get a pleasing background:
1) stand somewhere so that the house does not show, i.e.
only plants in the background,
2) open the lens as wide as possible to minimize the
depth of field (see DOF) (f/2.8 for
the 105mm lens & f/2.8 for the 300 mm ED AI-S Lens)
479 Clay St. Photos taken in A mode. No
coping, Only format conversion in Photoshop, no
adjustments. Nikon D300s.
|These are in the
Sun. Which makes it harder to see the
subtle colors of the patina.
|I'd like to try taking this photo when the
subjects are in shade. At about 5:40 pm on
8 Aug all the statues were in direct
sunlight. Checking Sun
Rise Sun Set shows that sunset today is at
8:18 with twilight at 8:48, so a time between
those would be best. Or between 5:51am and
6:20 am tomorrow morning. The idea is to
take a shot framed like the one above at f/2.8
(note the front bird is slightly out of focus)
except with the front bird in focus and another
with the rear bird in focus in order to focus
stack. In addition an exposure with the
lens stopped down so they both are in focus in a
In this mode the camera sets both the f/stop and the
shutter speed. In the simplest case this amounts to
a Point-And-Shoot mode where no control by the
photographer is involved in the exposure.
On many cameras by pressing a button and then turning a knob
the Exposure Value can be changed from whatever it
was. This is typically used after an exposure has been
made and you want a lighter or darker image. On
cameras with a visible histogram no pixels at the left means
overexposed and no pixels on the right means underexposed.
Dynamic Range (Wiki)
A theoretical ideal would be
to expose the image so that you could see detail
(brightness variations) in the deepest shadows and in the
highlights. But there are limits to the dynamic
range that can be seen and captured and displayed.
The human eye can see somewhere in the range of 10 to 14
stops, film 7 stops, DLSR camera 11 stops, (Wiki
everything in the room painted black (movie theaters are
mostly this way). Also see Dark Frame Subtraction
Lab #02 Measure the Dynamic Range
By setting the metering
mode to spot
and the exposure mode
to Aperture (A)
(the ISO can be
200 or as needed) then point to an area where you want
to see highlight detail do a half shutter press and make
a mental note of the shutter speed, then point to an
area where you want to see shadow detail and do a half
shutter press and make a mental note of the shutter
speed. Each doubling (or halfing) of the shutter
speed is one stop.
ISO 200 & A = f/16
Shutter speeds: wispy clouds = 1/640, tree trunk
1/30 (/2=) 1/60 (/2=) 1/120 (/2=) 1/240 (/2=) 1/480
(/2=) 1/960 so a little over 4 stops.
Calculating Exposure Value
f/16 @ 1/640 = EV 17.32 and f/16 @ 1/30 = EV 12.91
difference is 4.41 stops. No dynamic range
A way to extend the
dynamic range is to make a number of exposures where the
f/stop and focus are the same but the shutter speed is
varied. This is done with the camera on a
tripod. Then the different images can be stacked
in resulting in an image with greater dynamic range.
Photoshop CS4 can do HDR by means of stacking, see Digital
201: Stacking Images
. There are other
programs that do HDR image stacking.
In the Camera
The high end Nikon cameras
can do some of this in the camera at the time of
exposure. In the Shooting Menu it's called Active
D-Lighting (Active Dynamic-Lighting). I like the
result of the Nikon in camera better than the stacked
image method. The images no only look better in
terms of brightness range they also seem to be in better
focus (maybe stacking results in a slight degradation of
This is different from the Nikon Dynamic-Lighting that
is done after an image has already been taken in the
Retouch Menu "D-Lighting".
|This concern with dynamic range
has been solved by using RAW files and changing
the Nikon D300s default setting from 12 to 14
bits per color channel. See:
Dark Frame Subtraction
Nikon calls this Noise Reduction (NR) and it shows up on
the D300s in the Shooting Menu with the title: Long exp.
This is a common practice in astronomical
photography. The idea is that large area imaging
chips are not perfect, that's to say there may be some
individual hot pixels or maybe one edge of the active area
is near a part of the IC that's thermally hotter than the
rest of the chip so there are some hot pixels in that
area. A way to mitigate the effect of these hot
pixels is to first take the normal exposure and take a
dark frame with the same camera settings. Then
subtract the dark frame from the normal image. For
example if the normal image was of a star field and there
was a hot pixel, then in the normal image you might see
and "extra star". But after the dark frame is
subtracted the "extra star" is removed.
This method is not limited to astro photography, but works
on any scene were there's a lot of dark areas were you
want to see detail.
Lab #1 f/16 Sunny Day Rule (Wiki)
Take four photographs
(best if done on a tripod so that each will be of the
1. P or Automatic mode
2. M or manual mode shutter speed =
1/ISO & f/16
3. A or Aperture mode f/16 & auto
4. S or Shutter mode 1/ISO & auto
If the camera is working properly you would expect the
P, S and A exposures to all be the same and maybe the M
exposure to be off a little.
Here is an example for the Nikon D300s
|Note: P, S & A=14
something is wrong
since the EV for
M is off by 1.6 stops
Troubleshooting: Tried different lens.
Tried pushing and holding two green buttons to
Tried Resetting the Shooting and Custom menus (second
item from top).
Sent question to Ask Nikon - 23 Aug 2011. The
response was switch to spot metering.
The result of
spot metering is no change.
The results are the same as before.
The only thing I've been able to think of is a problem
with the camera's ISO calibration. When in any of
the automatic exposure modes (P, A, S) the camera works
fine, but when using the f/16 sunny day rule it's
underexposing by 1.6 f/stops.
Here is data on the Nikon
(not s) ISO = 200
Here is the Nikon D60
|only off by 1/3 stop.
The Nikon D60 shows an Exposure Value of 15.6 in all
four exposure modes as does the Nikon D300 and D300s
when in Manual metering mode.
The discrepancy occurs with the Nikon D300 and D300s
when in one of the automatic exposure modes (P, A, S)
where the D300 (P, S, A) reports and EV of 16.6 and the
D300s (P, S, A) reports 14. Very strange.
If you know why this is let
Most image sensors (Wiki
are made using either CCD (Wiki
or CMOS (Wiki
technology and are made of Silicon using common semiconductor
methods. The cost to process a wafer is essentially
independent of how many parts are on the wafer so the smaller
each part is the lower is it's cost. For a monochrome
image sensor a pixel is one photo diode on the chip, but for a
color sensor a pixel is made up of some number of red, green
and blue pixels for example the Bayer color filter (Wiki
where there are two green, one red and one blue diode per
pixel or a larger number when the camera format is set to
output a smaller number of pixels per image.
ranking of DSLR image sensors
for color depth
(portraits), dynamic range (landscapes) and low light - hi ISO
35 mm film (Wiki
is 24mm high and 36 mm wide (camera in normal landscape
position) which is a 1:1.5 aspect ratio. Only very high
end DSLR cameras have full size image sensors because they are
expensive. Most DSLR image sensors are smaller than a 35
mm film frame (Wiki
If you have a lens that works on a 35 mm camera and use that
lens on a DSLR with an image sensor that's smaller than a full
frame then the effective magnification is higher than you
would get on the 35mm camera. One way this is expressed
is "crop factor" which is 1 for 35 mm film, 1.5 for the Nikon
DX sensors, etc.
Number of Pixels
When the number of pixels is
very small the image has grain. Screen printing is in
the 50 lines per inch area and a 600 DPI laser printer is
around 100 lines per inch. High end photographic prints
are at 300 DPI. So to make an 8" x 12" print the image
should be 2400 x 3600 pixels which takes a 8.6 Mega pixel
image sensor. So for most practical photographic needs
image sensor sizes higher than this don't offer an advantage.
Size of Pixels
Each pixel is like a bucket that
can hold some number of photons. The smaller the pixel
the fewer photons it can hold. Because of noise there's
a radio of the maximum number of photons to the noise level
and the number of bits in the analog to digital converter used
depends on this ratio. Cameras that have excellent low
light performance (Nikon D3S) are full frame but only 12 Mega
pixel chips with a pixel pitch is 8.4 um.
This has to do with how the
stutter release will occur.
Single Frame (S)
Note: If the auto focus mode
is set to prevent an exposure when the image is out of
focus pressing the shutter may not cause an
exposure. For a first time user this looks like the
camera is broken. (guess how I know this).
One way around this is to switch to Manual
Another way is to change the _____ setting under
Menu / ? / ?
Continuous Low Speed (CL)
1 to 7 frames per
second. Set in Custom Settings D5
Continuous High Speed (CH)
Up to 7 frames per second as
long as the shutter is held down.
sound effects turned off and
mirror movement slowed down?
Self-Timer (clock icon)
The self timer adds a delay
after the shutter release is full down. BUT, the
focusing happens when the shutter release is at half down so
there's no focusing after the timer trips the shutter.
Therefore not good for self portraits. For all hand
held shooting I have the timer set to 3 seconds.
Mirror Up (MUP)
A drawback of the SLR design is that the mirror needs to be
raised prior to an exposure. The "mirror slap" does move
the camera. On the Hasselblad
it's a real
problem. On the Nikon D300s it's still noticeable,
that's why they have a Mirror Up (Mu) option on the Release
Mode Dial at the upper left (viewed from behind). When
the shutter is at half press the camera does the auto focus
and at full press the mirror locks up. If you wait about
30 seconds the exposure is made.
In film cameras the color
balance (White Balance) is determined by the film. So if
the light does not match the film in terms of color
temperature a correction must be made or the color balance
will be way off.
It turns out that the Nikon D300s and D60 have AUTOmatic as
the default setting for color balance. So, when a photo
is taken of the color test chart (see Bruce Lindbloom below)
using strobe lights or an incandescent lamp the resulting
images are identical. That's to say that the AUTO mode
works. The special lens caps
& color targets
that are available may not be needed
for these camera models, or may only be needed for very
exacting color rendering requirements.
Note that when using a RAW file format, such as NEF for Nikon
cameras, you can make white balance adjustments in the Adobe
Camera Raw (ACR) application just by clicking on a part of the
scene that you know contains no color, such as a white
background or a gray card. So if when taking photos
where color balance might be an issue you may want to include
a gray card in the first frame to set white balance.
Then in ACR make a group of all shots taken in that light and
as a group set the color balance for all of them based on the
gray (or known white) reference.
In order for the colors in an image to look like we're used to
seeing them the camera needs to be set for the color
temperature of the light that falling on the subject and
background. The default camera setting is for daylight as
the source of light. If a photo is taken indoors where
the light is from incandescent bulbs the color in the final
image will appear to orange. If the indoor light is
from cool white florescent lamps then the image will appear
There are a number of ways to get the desired color
balance. I say "desired" rather than correct because for
artistic reasons you may want to deviate from the "correct"
color balance which would render each color in such a way that
it was as close as possible to matching the subject so that
the final image is more pleasing to the eye. This
usually means warming up the color temperature when there are
skin tones in the photo.
- has technical info related to color spaces - After
downloading the four reference images, when that folder was
selected using the Costco Java applet only two images were in
the directory (probably the 8 bit per channel images).
The preview images were very different one had a lot more
dynamic range than the other (maybe the gamma 2.2
image). I've ordered a 16x20 posterboard to both see how
it looks and to use as a test subject for White Balance tests.
Camera Color Setting
For Nikon SLR cameras there are color balance settings.
These can be accessed three ways:
1. Pressing the WB button and turning the sub command (front)
2. Using the White Balance menu:
3. Pressing the WB button and turning the Main command (rear)
||Requires "D" (Distance is sent
or "G" (camera controls aperture) lens.
Takes into account the built-in camera flash.
|1. Pressing the WB
button and turning the sub command (front) dial.
||The white balance is
measured using a gray or white subject
or is transfered from another image stored in the
has the desired color balance.
There are special lens caps with white translucent material
(on order 22 Aug 2011) and also special two sided "lens) that
has slots (on order 22 Aug 2011). These are to support
the PREset Manual color balance mode where you acutally
measure the light. More on this later.
When the Nikon D300s is set to AUTO color balance it
automatically corrects the color balance (white
balance). For example the photos of the test chart when
illuminated by studio flash units looks the same as when
illuminated by a 4800K tungsten lamp.
Flash On Camera
Many cameras have built in
flash. Some are always active and others are of the
pop-up type that automatically pop-up or that require manual
opening. These are low power (maybe 10 Watt Seconds) and
so have limited use.
Red Eye (Wiki)
When the flash is close to the lens it may cause the subject's
eyes to glow red. This typically happens in dim settings
with cats, people, etc. Most cameras with a built-in
flash have a Red Eye Reduction mode where there is a short
flash that preceeds the exposure that causes the subject's
pupils to close down prior to the actual flash exposure.
The light falls off as the square of distance, so if a subject
is properly exposed by the flash at 4 feet then at 8 feet (2 x
the distance) the light will be 1/4 as bright. This
effect can be used to cause the background to be black.
||Photo taken in the
daytime. Nikon D300s with SB-900 flash.
A mode set to f/36.
If you want the light to be brighter at some distance then
increase the camera's ISO speed and open to a small f/stop
(for example f/2.8).
It may be possible to control the flash output so that instead
of providing all the light on the subject, it will only
provide light that's 1 or 2 stops less. This allows
filling in shadows that otherwise would be black to very
dark. This can make outdoor photos much more pleasing.
Is the energy stored in the
capacitor that discharges into the flash tube to make
light. It is not related to the watt rating shown on a
household light bulb. Watt seconds are the same as
(and probably most on camera flash units are similar).
The Nikon SB25
off camera flash
uses a 1,400 uF capacitor and charges it to 300 Volts, so WS =
1/2 * 1.4E-9 * 300 * 300 = 63 WS. Most of these on
camera flashes use a smaller capacitor maybe 200 uF so they
have more like 10 WS energy.
The Guide Number (Wiki
is a measure of the light output from a flash (bulb, or
electronic). It assumes the shutter is open long enough
to capture all the light. It also assumes the film speed
is ISO = 100. Since this is the linear ISO number
multiplying the ISO number by 4 should double the distance
(the same as doubling the guide number).
Guide Number = (flash to subject distance) * f/number.
Note guide numbers have a length unit, such as 90 feet or 30
Note: Light falls off in
what's called the inverse square law (think of the wave
front as a sphere who's area is expanding as the square of
the distance from the center). The f/number relates to
the diameter of the effective lens opening and so is
proportional to the square of the light gathering area of
The lamp converts electrical
energy to light at about 40 lumens per watt.
The D300s built-in flash has a guide number of 56 feet when
ISO is 200. The SB-900 guide number varies between 13
meters (42.6 feet) to 57 meters (187 feet) depending on how
the flash zoom is set (and at an ISO of 100). Notice
that the built-in flash is specified at ISO 100, but the
external flash is at ISO 200 (ISO 200 is the lowest value
unless you degrade the image).
The key difference between film
photography and digital photography is that with digital you
get a file instead of a negative. The digital file
allows doing much more with the image than is possible with a
physical negative. As the number of pixels in the image
sensor gets larger so does the file size the camera produces
so there's a trade off between how many photos can be stored
in the camera vs. the quality of the resulting images.
Some cameras produce images that take up so much file space
that they can only hold a single image and so are called
"tethered" meaning that they are best used while connected to
a computer. Examples of this are astronomical cameras
and Hasselblad digital cameras.
There are advantages to connecting DSLR cameras to a computer
when in a studio setting.
Most digital cameras allow the photographer to select what
size images will be stored. The default setting may be a
medium size offering a compromise between maximum image
quality and maximum number of images on the memory
medium. I set my camera to the maximum available image
size and live with whatever the number of images stored.
This way there is the most room to work with the image in post
There are a number of file
types that can be used to hold images, both still and
moving. (Wiki: Image
of Graphic File Formats
). Each of them came
about because it offered something special for a specific
application. Only a small number of them are used as
the output file type for cameras, which are the ones listed
below. Others are used for things like printing, web
browsers, scientific applications like astronomy, computer
aided design (Autocad), etc.
By far the most common file type is the jpg. (Wiki: jpeg
Photographic Expert Group). It's advantage is that the
file size can be smaller than other file types like bit map
I convert to this format as the last step when using an
image for a web page or to email someone, but do not use it
as a camera output file type if the camera supports a non
lossy file format. The reason is that every time a
.jpg file is opened in and subsequently saved the quality is
degraded, sort of like working with successive generations
of an analog film image.
Tagged Image File Format (Wiki
) is an
option on many cameras. It's a loss-less file format
so the image does not degrade with multiple
generations. The Nikon D300s generates a file of about
35 Mega Bytes when in the highest resolution image
mode. This is my standard camera output file.
RAW (Nikon: .NEF)
This file type (Wiki: RAW
has the smallest amount of image processing done by the
camera and so is the most powerful in terms of allowing post
processing "developing" software to manipulate the
image. Different cameras have different image sensors
and treat the resulting data in different proprietary
ways. For example Canon and Nikon have scrambled the
data in each of their raw files so competitor can not tell
how their cameras work (Nikon calls it's RAW format
(NEF). So to use RAW files you typically need a
software add-on that will decode the RAW file from your
THE H-U-G-E advantage of using RAW files is that the dynamic
range is much greater than the 8 bits per color channel of
.jpg files. The Nikon D300s supports either 12 or 14
bits per color channel! This extends the dynamic range
by 6 stops!
The RAW file is very much like a negative and gives you a
better quality, flexibility and control than using other
The Nikon has an option of outputting a NEF and a jpg file
of each shot. This is not a good idea because if you
get thumbnail images of both it's easy to get confused and
select the jpg as the image to use in your work flow.
Better to only output the NEF file.
Note that computers know about .tiff, .jpg and other file
types and so when you open a folder and select the Thumbs
option you see small versions of the images. The
thumbnail versions are not available when working with RAW
files so they are harder to work with. (Sometimes my
computer shows a preview of the NEF file) That's why
there are software programs just for managing images.
For example Lightroom (Wiki
supports RAW formats.
Adobe Bridge (comes with Photoshop CS4) allows using two
types of meta data to manage images. Some meta data
comes in the EXIF (Wiki
from the camera and other meta data you can add to an image
Adobe Camera RAW (ACR)
In Photoshop or Bridge the Camera RAW plug-in allows
working with RAW files. Note each brand of camera
has their own file format (suffix on the file name such as
.NEF for the Nikon RAW file format). Edits in ACR do
not permanently change the image file, but are a process
that's applied to it.
There is a lot of control available in ACR of exposure,
color balance, and things like fill light as well as
adjustment of the histogram.
At the bottom of Camera RAW there's what appears to be a
link that allows setting how you want to handle the RAW
files and it has options for:
- 8 bits/channel. Better reds than sRGB (see
203: Color Management
Color Match RGB - early Mac 8 bits/channel
ProPhoto RGB (Wiki
- Kodak 16 bits/channel - But I don't know of anyone who
makes prints = poor choice in ACR
- for monitors, HDTV, etc (the default for most
|It seems that 16
bit/c printing does not offer much advantage
over 8 bit/c - Hype
or Hero Take 2: 16 Bit Printers.
But my guess is that doing all the work up to
the printer output at 16 bits/c will result in a
higher quality image.
Note the "Print" command and most computer
screens are "24 bit color" i.e 8 bits/channel
Costco only accepts 8 bits/channel image files.
(first version to support focus stacking)
|5.0 to 5.7 (have
| to 6.6
Premiere Elements 10
| to 6.6
|Lightroom 2 (ver
2.7 for ACR 5.7)
The Nikon D300s can be set to use AdobeRGB and Adobe
Camera Raw (ACR) can also be set to output this color
space. It's what I'm using as of 7 Nov 2011.
Above this will be a few
lower (-) resolution options and above it will be a few
higher resolution (+) options.
1024 x 1542 pixels (3.4" x 5.1") to 4081 x 6144
pixels (13.6" x 20.5")
These are probably arrived at based on the Bayer color
(Kodak Patent 3971065
Resizing in Camera Raw (external
) - they say take the nominal size in ACR and
use Photoshop Bicubic Smoother when
increasing the image size (and Bicubic Sharper when
size in ACR may lead to a higher quality image
than when using Photoshop, but that's not clear.
You can increase the resolution in Photoshop
IMAGE \ Image Size, but this is done by
interpolation so is not really adding anything.
I've set it at 300 pixels/Inch (was
at 240 PPI). 300 PPI is for a quality photographic
print, 72 is for newspapers).
Sharpen For: (maybe this is used when the output
from ACR is not going to Photoshop)
Open in Photoshop as Smart Object
More to learn about this
Digital NeGative is an open
standard RAW file format developed by Adobe. It's
possible to convert from RAW to DNG. Some cameras
have native .DNG output files, like Hasselblad (Wiki
When saving DNG files from ACR you have the option of
backdating the version number. This was necessary
when sending a file to Bragadoon
Image Out of Camera
There are a number of common
ways to get the digital image out of the camera so something
can be done with it.
This is the method I used to use. The cable is always
plugged into my desktop computer so it's quick and easy to
let the Nikon Transfer program download only the new photos
from the camera to the file where I store them.
It's possible to wear out the USB-B Micro connector
in the camera! Ask how I know this. The
repair cost is over $200 and you loose the use of
the camera for a couple of weeks.
Note: I may take a dozen or more photos a day but
more importantly may make 0 to 6 USB connections to
the camera per day on a 24/7/365 basis.
I'm now looking into other ways of getting the
images out of the camera that involve a wireless
connection. That means no mechanical stuff to
wear out. See Eye-Fi.
||There are three
common USB cables all of them have the USB-A male
connector that mates with standard desktop computer
USB ports. The other end may be the USB-B
5-pin Mini Cable, like the one shown that's used on
the Nikon Digital cameras, or the USB-B Micro cable.
Memory Cards and Sticks
The Nikon D300s uses two cards, one a Compact Flash and the
other an Secure Digital (SD). It's possible to pull
the card from the camera and insert it into a computer, but
not all computers will have a compatible card reader, it
seems a special adapter is always needed. For a small
number of photos this method is more work than it's worth
for me. But to move all the photos on a card, like
after a vacation or all day photo shoot this is a much
faster way to move a lot of data.
Many digital cameras support PictBridge which allows the
images to be directly printed using a USB cable or a memory
card. I haven't used it because you have no control of
the image, it's just whatever the camera image looks like.
There are now (2011) two kinds of adapters that allow the
camera to be part of an IEEE 802.11 WiFi wireless network (Wiki
One is a Compact Flash card (see Eye-Fi
on the Nikon
page). But it's very picky about what computer you use
and what software is already on that computer,
not working for me.
It's mainly a one way
system that downloads photos to your computer as they are
taken. There's no provision for camera control.
$100 price range.
The other is an external hardware adapter like the Nikon
This system allows both downloading photos and camera
control when using Camera Control Pro 2 (optional).
$1000 price range.
In the not too distant future the Wifi interface will be
built into the camera. This would allow remote flash
units to be standardized independent of manufacturer where
each one has it's own IP address. Multiple camera
setups and many other now not thought of things will be
DSLR cameras that have movie capability typically allow the
use of an HDMI cable (Wiki
to view the movie on an HD TV set. Like the USB cable
there are full size and mini ends, with the mini end common
for the cameras. Once connected you can use the HD TV
to view still images either as selected by the normal camera
viewing method or there might be a slide show mode. I
haven't explored this.
Costco Photo Processing
Dec 2015 - The ONLY way to use a printer profile is to pickup
the print from the store. If you have the print mailed it
comes from Auburn, WA and you have no control over which of many
printers they use.
This is very different than what used to happen, i.e. the local
Costco printed and shipped.
So far I've ordered "Enlargements & Posterboards" and a
Note: "Gallery" means one of their stock photos.
Posterboards are just under 0.050" thick and are a very cost
effective way to put photographs on your wall.
Note when uploading a file there are two things I have found
result in a higher quality print.
1. .TIF files look better than .jpg files (based on the same
image and about the same file sizes)
2. Be sure to select FULL Resolution, the default is Fast
upload. I can't understand why they even have the Fast
Resolution is based on 300 DPI
The camera resolution sets a limit on the size of enlargement
that's possible from a single image.
Note pat attention to the cropping options. If done
incorrectly you may not get what you expect. I now make a
special file from Photoshop where the size is the same as the
print. So, if I did that correctly, there should be no
When shooting in RAW (NEF) mode and with AUTO color balance
selected the camera may choose a crazy color temperature, like
happened when shooting fall tree leaves. The camera choose
4100K. The resulting print had almost brown leaves, not
bright red. So that was fixed in Adobe Camera Raw.
This is the first time I've had a problem with the camera
messing up the color balance, but it can be fixed in ACR.
Another problem is that the default at Costco is to Auto Correct
your color balance. But you have the option of turning
that off just prior to when your order is submitted. You
can click on edit options and modify (1) what gets printed on
the back and (2) check a box to turn off Auto Correct.
I've done that and when you come back to the place order page
you can see that I've changed both of them.
For using Costco store specific color printer profiles, see my Digital
Photography 203: Color Management
14 Oct 2011
This is the default method
I've been using. But when trying to upload a 75MB tif
image the error message when it failed suggested using the
single file uploader.
The single file uploader is a
Java application. It too failed. The error
message suggested using Windows IE and ActiveX.
There seems to be two phases
to the upload. This too failed. Calling the
support phone number I learned that their idea is the file
size limit is 30MB. I complained that offering large
print sizes but not supporting the file size needed for 300
Dots Per Inch means that it's a hollow print. They
suggested that I use 150 DPI (DPI). The full frame NEF
(RAW) image was resized (Bicubic sharper) to 30" wide at 150
pixels/inch and Image/Mode was set to 8-bits/color channel,
resulting in a 35MB file size tif image. This file
loaded in about 12 minutes with no problems.
together a higher resolution file can be built
up. Also RAW images can be stacked to maybe double the resolution
have a 1.5
Note 1: The TIF file made for the 20x30 posterboard print is
about 155MB which it too big to upload. The machines at
the Costco store do not accept tif files. So it looks like
the image quality must be degraded by changing to jpg file
format and maybe also reducing the file size.
Using Photoshop 7 on the 155MB TIF file to make a jpg file with
the highest quality resulted in a file size of 17MB which took 5
minutes for upload at "Full Resolution".
CVS has a photo department that offers a 20x30 poster print for
$20, but there are a couple of problems.
It's not clear what they mean by "poster", it may just mean
something large rather than poster board.
CVS has a file size limit of 8 MB, way too small to get any
decent resolution on an 8x10 print let alone a 20x30.
||Note: You can mount
posterboard directly to a wall using Elmer's Tack (is
Orange) (Wiki: Blu Tack)
Elmer's Tack applied as small balls on the four corners
of an 11x14 Costco Posterboard.
It also works on framed pictures that are hung from a
wire where they seem to always be
tilted. One small ball on a lower corner keeps the
If you get it on the front it can stain the posterboard
orange, probably also the wall.
|Staples has Henkel Duck
Poster Putty that's blue in color and maybe works better
than the Elmer's Tack (photos have fallen down).
I've used this before and like it.
|Museum Putty is
not the stuff to use for this. It's job is
anchoring things so they will not move in earthquakes.
Possible Future Topics
(external camera mounted & Studio)
Many digital cameras have
built-in flash capability and the newer high end DSLR cameras
have very sophisticated flash features that go far beyond the
first generation Photo-flash
equipment. Nikon has their proprietary Creative Lighting
System on the newer cameras and hot-shoe flash units.
But there's not any CLS studio flash equipment. (see Nikon page CLS
Direct, bounce, soft box (tent), diffusers, reflectors
Camera Control Software
Allowing remote camera
operation or things like a photo booth. For example
Nikon Camera Control Pro 2.
Post Processing Software (Stacking)
Software used after the image
has been taken. The most common being Photoshop, but
there are the basics like Paint that comes with
Windows. Adobe has a number of programs that are
related to photography and image processing. Photoshop
Hasselblad has Phocus for free but requires 64 bit operating
system like Windows 7, Bridge (Wiki
and Acrobat (Wiki
are some of these. See the Wiki
for Adobe Creative Suite
for a bunch of them.
By far the most common things I do in Photoshop are:
- Crop the image
- Adjust the histogram
- Erase the background on product photos (this allows
shooting without a studio)
correction software in addition to noise reduction and film
The common ones are
polarizing, neutral density, color (typically used for
B&W images), color correction used on a camera or flash,
and scientific (like IR).
The camera takes a number of
exposures where some parameter is changed. The most
common is different exposures in terms of shutter speed
and/or f/stop. But the output of a flash can be
bracketed as can the color balance.
Using a modern DSLR as a movie
camera has many advantages over using a handicam.
Stereo sound is standard when an external mike is used.
The key features are:
- the ability to change the lens
- the ability to change the ISO speed. This allows
shooting in ambient light (no flood lights needed)
- the ability to shoot in HD modes (9:16 image
format) YouTube has increased it's file size limit
to allow HD images.
It's fairly straight forward
to take a couple of color photos and post process them into
a single 3D image that can be seen using Red-Blue glasses (scroll down
a little to see still
So far (2016) there's not a cost effective way to take a 3D
movie to display on my Sony TV (not Red-Blue but rather
left-right eye blinking full color) which can be edited.
: Stacking Images
202: Close-Up, Macro & Micro
Digital Photography 203:
Digital Photography 204: Studio Flash
High Dynamic Range Photography
- a number of photos
8550 Chetle Ave. Unit B
Whittier, CA 90606
David Trevino - Manager
(562) 968-2038 (fax)
"Light Field Camera" - focusing is done after taking the
and method for acquiring, editing, generating and
outputting video data,
date: Nov 20, 2009, 348/345, 396/79, 382/255, 396/89
field data acquisition devices, and methods of using and
Dec 8, 2009,348/349, 348/222.1,348/345,348/340
Filing date: Apr 27, 2011, D16/203
Transmission of Image Data Based on Device Attributes,
date: Jun 14, 2012, 345/419, 345/501, 382/276
Storage and Transmission of
Pictures Including Multiple Frames, Filing date
8, 2011, 348/222.1; 348/E05.031
Objects and/or Facial/Body Recognition, Filing date
Jul 27, 201, 382/118
Metal Picture Frame, E. Cox, Jan 22, 2002, 40/785
40/782; 403/294; 403/401 -
Corner joint does not distort when tightening clamp screw
Archival Metal Frames
- Artcare 8-ply gallery white mat
- Artcare 2-ply mount board
- UV glass
Ukiah Area Photo Related
Signs & Graphics
435 North Main Street
Fort Bragg, CA 95437
alan at braggadoon . com
707 964 5050
Can use DNG version _____.
125 N. State St.
Ukiah, CA 95482
343 W Robles Ave.
Santa Rosa, CA 95407
Rileystreet Art Supply
103 Maxwell Ct.
Santa Rosa, CA 95401
260 S. School St.
Ukiah, CA 95482