FAQ or Answers to Frequently Asked Questions Section 33
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These files are available in SECTIONS.
This is Section 33 and its contents are listed below.
33.01 -< Starting points for using Konica and Kodak Infrared films >-
33.02 -< Intro to Gross Specimen and General Photography - tutorial >-
33.03 -< UK Company that makes microscope (and other?) adapers >-
33.04 -< Improvised Contrast Control filters from Rosco materials >-
33.05 -< Reducing overexposed IR film and others too >-
33.06 -< Tips for photographing the sun >-
33.07 -< Stage Photography Recommendations >-
33.08 -< Photographing Soccer Recommendations >-
33.09 -< Sprint Photographic Chemicals >-
33.10 -< Artcraft Chemicals - Photo Chemicals Supplier >-
33.11 -< A few non-US magazine recommendations >-
33.01 -< Starting points for using Konica and Kodak Infrared films >-
> I've just bought a Hoya R72 filter, I wonder if someone has worked with this
> filter apparently it cuts the spectrum at 720 nm. 1.- How do you expose Kodak
> HIE and Konica IR with this filter ? 2.- If I use it with IR Ektachrome can
> I obtain something ?? or I will only waste my film.
I can't help you with HIE, other than to say I'd try some test exposures
centered around EI 200, but I can help with the Konica. This film only goes a
little past 750 nm (nanometers, the wavelength of the light). This is
sufficient to record the infrared fluorescence of chlorophyll, which gives the
effect of white foliage in B&W infrared photos.
As a result, a 720 nm filter, whose cutoff (3dB) point is 720 nm is eliminating
all but the IR light. I use a #23 filter at an EI of 10, a #25 at EI 8. Since
you are filtering even tighter, and since I have no idea how you process, I
would start at EI 10, and make identical test exposures at EI 8, EI 6, and EI
4, also. Then, I'd process the film as described in the instructions, pick the
best negative and go with it. Waste some time and effort on this film, it's
really nice. In order to get every bit of speed the film can give, I normally
process it in dilute microphen (1:3), and the result is good speed, great
sharpness, and unblocked highlights. Forget fine-grain developers, as the
grain is like Pan-F or TMX at worst. I haven't tried it, but Diafine might
give an extra stop or so. It seems to work with everything else!
Regarding, EIR, remember that it is a film which records blue and green as
blue, records yellow-red as greens, and IR as red. If you use your IR, all your
slides will be reds! Far better to use a #12 yellow (minus blue), or failing
that, even a # 8 yellow. This way you'll get all three dye layers to add to the
image. I saw a few slides once shot through a Cokin (I believe) sepia filter
that were wild! Remember that the preconcieved rules went out the window when
you loaded this stuff! My few experiences with it were that I got good
exposures depending on Kodak's exposure recommendations, and using my SRT-101's
meter set to Kodak's recommended EI.
Edward M. Lukacs, LRPS, Miami, FL, USA, email@example.com
I don't know about the Konica since its response is pretty low beyond about
750 nm. I have used the Kodak HIE and I would suggest the following supposing
the Hoya R72 filter is very similar in spectral transmission characteristis to
the Wratten 88A. The following is from a Kodak data sheet:
Film Speeds - these numbers are guides only - use them as starting points:
Film Speed in ASA rating - assumes development in D-76
Kodak Wratten Daylight or
Gelatin Filter Electronic Flash Tungsten
No. 25, 29, 70, 89B 50 125
No. 87, 88A 25 64
No. 87C 10 25
None 80 200
As for your second question, if I use it with IR Ektachrome can I obtain
something ?? or I will only waste my film ... the answer is you will get
something ... red transparencies.
Note 33.02 -< Introduction to Gross Specimen Photography - Tutorial >-
AN INTRODUCTION TO PHOTOGRAPHY IN GENERAL -
AND GROSS SPECIMEN PHOTOGRAPHY IN PARTICULAR
A Guide for Residents Who Have Had This Unwelcome Chore Dumped Upon Them
Ed Uthman, MD (firstname.lastname@example.org)
Diplomate, American Board of Pathology
At its birth about 1824, photography as practiced by its first devotee, Joseph
Nicephore Niepce, was a messy, all- consuming pursuit that made use of such
substances as bitumen of Judaea, lavender oil, and pewter. Today, chemical,
mechanical, and electronic technology has made photography a neat, transparent,
facile technique which we may easily apply to another messy, all-consuming
pursuit: gross anatomic pathology. Despite the amount of automation available
in photography, it is important to grasp a few general principles, so that we
may use to our advantage a few powerful controls we have over the photographic
The main considerations in gross photography are exposure, focus, image size,
composition, color balance, and film selection.
This is essentially the problem of balancing the amount of light coming through
the lens with the sensitivity of the film. We seek the ideal exposure and
eschew the underexposure (slide too dark) or overexposure (slide too light).
The determinants of exposure are:
A. FILM SPEED, measured as arbitrary standardized units ("ISO" or, formerly,
"ASA"). ISO and ASA are numerically equivalent units. The film speed depends on
film manufacturing process and type of development used on the exposed film.
Although films are packaged with a stated ISO rating, some may be "pushed" to
higher speeds by special processing techniques. This should be kept in mind
before throwing away valuable film you have mistakenly underexposed. The faster
the film, the less the resolution (causing increased "graininess"); also colors
are more subdued in fast film (such as Kodacolor 1000) than in "slow" film
(such as Kodacolor 25). The graininess and subdued colors of very fast films
can be used for artistic effect but are of no value in technical photography.
Therefore, we tend to choose slower films for our gross lab cameras, so that we
may produce pictures with the greatest resolution and most accurate color
rendition. A film faster than ISO 160 should probably not be used.
B. APERTURE, the setting of the iris diaphragm in the lens, determining how
much light is allowed through the lens into the camera. Aperture measured as
"f/ stops" (f/2.8, f/4, f/16, etc). The f/ ratio is calculated by dividing the
focal length of the lens (see below) by the diameter of the iris diaphragm
opening through which light passes. Therefore, the greater the diameter, the
more light is let in, and the smaller is the f/ ratio. Each f/ stop is 1.4 (the
square root of 2) times the preceding f/ stop. Each "stop" multiplies the
amount of light by 2X. As an example, f/1 lets in twice as much light as f/1.4
and four times as much as f/2. The "speed" of the lens is its f/ ratio at its
widest aperture setting. An f/1.2 lens is considered very "fast," while an
f/5.6 lens is "slow." Generally, fast lenses are more expensive than slow ones
and in fact do not have as good corner-to-corner resolution as slower lenses.
Because we generally have plenty of light at our disposal in gross photography,
we opt for excellent resolution over lens speed. Most lenses for our purposes
are f/2.8 to f/4 at their widest aperture settings. We typically choose to
"stop down" our diaphragms in most cases, because almost all lenses have
optimal resolution when not used at their maximum aperture. The "ideal" f/ stop
is generally taken as 2 to 2-1/2 stops "down" from the maximum aperture. For an
f/2.8 lens, therefore, the optimal aperture setting would between f/5.6 and
f/6.7. The other reason to stop down from maximum aperture is to improve "depth
of field" (see "Focus," below). I personally shoot almost all my specimen
photos at f/8.
C. EXPOSURE TIME, or "shutter speed," measured in seconds or fractions of
seconds (1/30 s, 1/1000 s, etc) represents the total time the film is exposed
to the focused image. It is determined by setting the camera shutter to open
for a specified length of time.
Effects of various shutter speeds:
1/1000 sec - 1/60 sec: These are OK for hand held camera in existing light.
1/60 sec : Always use this with electronic flash, since just about all flashes
are specifically synchronized for this speed. Using a slower speed (e.g., 1/30
sec) will also work, but a faster speed (e.g., 1/125 sec) will ruin the picture
by failing to expose part of the frame. Note: Some of the more modern and/or
expensive cameras allow flash synching at 1/125 second or faster speeds, but
make sure this is true of your camera before trying it.
1/30 sec - 1/2 sec : We tend to use this range for tripod or copy-stand work,
including gross photography. This range is generally not acceptable for
hand-held cameras, because most people cannot hold the camera still enough for
this length of time. By using these slower speeds for gross photography, we
allow ourselves the luxury of smaller apertures (giving us good depth of field
and maximum resolution from the lens) and slower films (giving us maximum film
resolution and best color rendition).
For example, each of the following exposure parameter set- ups give the same
exposure. Which would you choose for a gross photograph taken on your copy
stand, assuming you have a camera with an f/4 lens?
A. ASA 50 film; f/4; 1/30 sec
B. ASA 50 film; f/8; 1/8 sec
C. ASA 200 film; f/16; 1/8 sec
I would choose set-up 'B.' Set-up 'A' involves shooting at maximum lens
aperture, at which lens resolution is not the best. Set-up 'C' lets us stop
down the aperture for good lens resolution but requires us to use faster film
with poorer resolution than the ASA 50. Therefore, 'B' looks like the best
Even though a good copy stand will keep the camera motionless and allow long
exposure times, there is a theoretical problem, called "reciprocity failure,"
which may interfere with color balance in very long exposures. But this is
never a problem as long as you don't allow the exposure time to exceed 1/2
second, and you'd probably not notice it even if you shot a 2-second exposure
(which may occasionally be necessary when using bellows at maximum extension;
How do you determine exposure? There are two ways to do this:
1. Most cameras have a built-in light meter that monitors the amount of light
coming through the lens. This meter attempts to optimize the exposure either by
averaging the total light hitting the film plane (an "averaging meter") or
using a small sample area (usually the center of the field) to measure the
amount of light focused on that particular spot (a "spot meter"). In an
"aperture priority" system, the meter then looks at the aperture you have set
on the lens and automatically adjusts the shutter speed to give the desired
exposure. In an "shutter priority" system, you set the shutter speed and the
light meter automatically adjusts the aperture. These functions are available
in what is referred to generally as the "auto" mode. In addition, most modern
cameras have a "program" mode, which completely automates exposure
determination by choosing both the aperture and the shutter speed for you. This
means all you have to do is compose the picture, focus, and push the button.
Program mode has been a boon for photography in general, because it allows you
to concentrate on composition and not have to worry about fiddling with
aperture rings and shutter speed knobs. There is, however, a price to pay,
especially in technical photography. The main problem is that automatic
exposure systems (except in high-end cameras) are standardized for snapshot
type photography, where there is no striking difference between background and
subject illumination. Also, an automatic exposure system will attempt to make
the subject have a "neutral" brightness. In technical photography, we do not
necessarily want this; we want brain to look light and spleen to look dark,
just like these respective subjects appear to us in real-time. Therefore, I do
not use the camera's automatic exposure system for routine specimen
2. Because of the above considerations, I recommend that you take advantage of
the rigidly standardized exposure environment of the copy stand and virtually
always use manual exposures. Determine the ideal exposure by shooting a roll of
film at various settings and then stick with this exposure when shooting
specimens. You can still use the light meter when faced with an unstandardized
situation, such as having one of your four floodlights burn out on Saturday and
not being able to find a replacement.
Parenthetically, I have found through experience that when shooting documents
of black printing on white paper, you should use an exposure one stop brighter
than your standard setting for specimens. For instance, if you normally shoot
specimens at f/8 and 1/8 sec, you should choose f/8 and 1/4 sec when shooting a
document. Never, never let the camera shoot black-on-white printed documents on
"Auto" or "Program," because the camera will think you want the white paper to
appear neutral and will force a bad underexposure.
Another hint: When forced with shooting pictures on a set-up you are unfamiliar
with, you may have no idea what settings to use. A good solution is to meter on
the palm of your hand (believe it or not, it makes no difference what color you
are; the palm of everyone's hand looks about the same to a light meter) and
note what settings the camera's light meter indicates. Simply switch over to
manual and enter these settings. Then you can shoot away and always get at
least acceptable results.
There are two things to consider here, methods of focusing and depth of focus.
A. Methods of focusing.
1. Autofocus. Most manufacturers today produce autofocus cameras aimed at
various markets. The most popular of these, aimed at the advanced amateur and
the professional, are probably the Minolta Maxxum series and the Canon EOS.
These cameras are packed with automation which allow automatic film advance and
rewind, automatic and program exposure modes, and autofocus. Automatic focusing
uses a system whereby a computer in the camera uses vertical lines in the
subject and focuses the lens by analyzing these lines. I have not used
autofocus systems in specimen photography but have experience with them for
snap shooting. The problem is that if there are insufficient vertical lines in
the picture, the focusing system with be fooled and can leave you with a
terribly out-of- focus picture. I have stuck with manual focusing for specimen
photography but would love to hear what the autofocus aficionados have to say
about its use.
2. Manual focus. In this method you simply view the subject through the
viewfinder and turn a focusing ring until the subject sharpens. If you have a
choice, I recommend a viewfinder with a split-field focusing prism to help with
critical focusing, but others prefer a focusing grid, which, as far as I know,
is only available on high-end cameras, like the Nikon F series.
B. Depth of field
It is easy to focus on a flat object, such as a slice of brain, but things get
stickier when photographing objects with depth, such as a windowed pediatric
heart specimen. Shooting these subjects requires a knowledge of the concept of
depth of field. It turns out that the zone of depth at which the camera is in
focus is greater at smaller apertures (larger f/ numbers) than at larger
apertures. Therefore focusing is very critical when the lens is "wide open" but
much less so when "stopped down." Let's say you are shooting an opened colon to
demonstrate, en face, a large villous adenoma. If you focused on the "top" of
the tumor (the part nearest the camera) and shot the picture with the lens
aperture at f/2, the tip of the adenoma would be in focus, but the sides would
be slightly out of focus, and the surrounding colonic mucosa would be totally
out of focus and probably not recognizable. However, if you stop down to f/16,
the entire specimen would be in focus. Since this results in decreasing the
exposure by six stops, you would have to compensate by increasing the exposure
time by a factor of two to the sixth power, or 64. For good depth of field and
optimal lens resolution, I use f/8 routinely and reserve f/16 and f/22 for
subjects like the windowed heart. Most cameras have a "depth-of-field preview
button" that lets you stop down the lens to its preset aperture, so you can
view how much depth-of-field you'll end up with in the resulting picture
(normally the aperture diaphragm stays wide open until the instant the picture
is taken, so you have a nice, bright viewfinder in which to compose the shot).
III. IMAGE SIZE
The size of the image in the camera depends on 1) the size of the subject (of
course), 2) the distance of the subject from the camera, and 3) the focal
length of the lens. The focal length is the distance from the lens to the image
when the lens is focused on infinity. The effects of lens focal length are as
The greater the focal length,
1. The larger the image appears for a given distance.
2. The farther away from the subject you can be for a
given image size.
3. The more critical the damping of camera motion to
4. The slower and more expensive the lens.
5. The less the sense of depth and perspective.
6. The less the curvilinear distortion of straight lines.
7. The _more_ flattering to the face in portrait
photography (makes face less moony and nose less
8. The _less_ flattering to the body in figure
photography (makes subject look stouter).
Lenses are classified in groups based on their focal lengths and other
16 - 35 MM (WIDE-ANGLE LENSES). Rarely used in medical photography, these are
best for landscape and architectural photography. They make landscapes look
more expansive and buildings more imposing. They tend to be extremely sharp
lenses that have excellent contrast.
50 - 58 MM ("NORMAL" LENSES). These are used for most routine work, including
gross photography. It is rarely necessary to use anything other than a normal
lens for our purposes except when shooting close-ups so extreme that the bulk
of the lens shadows the subject, so that it cannot be illuminated sufficiently.
In this case you need:
80 - 135 MM (MEDIUM TELEPHOTO LENSES).These are used for high-magnification
macrophotography to increase working distance, and for "over the shoulder"
intraoperative photography. For instance, you can be twice as far away from the
subject with a 100 mm focal length telephoto than with a 50 mm normal lens and
still get the same image size on film.
200 - 2000 MM (LONG TELEPHOTO LENSES). These are usually not used in medical
photography but are indispensable in sports, nature, and journalistic
MACRO LENSES. Operationally, the only thing special about these is that they
have an extra long focusing extension to allow you to focus on very close
objects. They are generally available in the "normal" focal length and the
medium telephoto ranges. For instance, Nikon makes two excellent macros, a 55
mm and a 105 mm. Since they are aimed at the technical market, macro lenses
tend to have excellent optics, are very durable, and are several times more
expensive than normal lenses of corresponding focal lengths. Most macros in the
normal lens category allow you to focus down to objects close enough to give
you a "3:1" or "2:1" ratio; that is, the image size is one- third or one-half,
respectively, the size of the subject. Most macro lenses can be used with an
inexpensive extension ring, which allows focusing down to 1:1 or "life size,"
i.e., the image size is the same as the subject size (Sigma makes a very nice,
not-too-expensive macro lens that focuses down to 1:1 without an extension
ring). This allows you to take some breathtaking shots of otherwise
unimpressive subjects, such as pituitary adenomas. You can even make a corpus
luteum look spectacular.
VARIABLE FOCAL LENGTH (ZOOM LENSES). These are very convenient for general
photography, since you don't have to move the camera so much. I am still
waiting for someone to come up with an affordable zoom lens that is macro at
all focal lengths and can focus on close objects. Many of the lenses advertised
as "macro-zooms" are really just zoom lenses that allow close-up photography
only at a fixed focal length. When in "zoom" mode, such lenses are not macro.
Other zooms supposedly have "continuous close focusing" throughout their range
of focal length, but the specs I have seen on these show that they all have a
minimal focusing distance that is too long for practical use on a copy stand.
My advice is too stay away from zooms unless you are really up on the
capabilities of the individual models and know exactly what you need.
BELLOWS. This is not a lens at all but simply a shade that extends the lens
very far away from the body of the camera. This allows you to take true
photomacrographs, producing an image size up to three times that of the
subject. For instance, when shooting a 105 mm lens on a bellows at full
extension, the Lincoln Memorial on the reverse side of a U.S. penny fills a
35mm frame. Multiply this magnification by the amount you get when projecting a
slide in a lecture hall and you get some idea of how Brobdingnagian a world you
can present to an awed audience. The only problem with the bellows is that
light intensity fall-off (as per the inverse square law) at maximum extension
requires you increase the exposure accordingly. Also you have to be extremely
careful about camera motion, which is magnified correspondingly.
If you consider yourself more of a technical type than an artiste, you are
probably intimidated by this aspect of photography. Although Ernst Haases and
Edward Steichens are probably born and not made, much technique of composition
can be easily learned by the average eye. In gross photography, first step is
good specimen preparation. This is what separates the excellent from the
mediocre; the inspired pathologist from the drudge; art from mere visual
documentation. After you get comfortable with the camera, you should spend
almost all your time preparing the specimen, with the actual photography being
a brief anticlimax. Here are some tips I find useful:
A. Cut away tissue that is of no interest, or that obscures the interesting
B. Use props to position the specimen when necessary. A slice of liver needs no
props, but a gallbladder looks better when you shove a few wads of paper under
the periphery to make it look like the saccular structure that it is. Modeling
clay is also a good material from which to devise custom props.
C. Watch out for the obtrusive ruler. A lot of pathologists remonstrate
incredulously when I tell them I almost never shoot a specimen with a ruler in
the field. For one thing, no one has made a ruler yet that is as unobtrusive as
I would like. Most specimens need no ruler, especially full organs or full
organ slices. We all know how big a lung is; if not, we're only there for the
free lunch anyway. If you really want to know how big the lesion was, just read
the gross; it even gives all three dimensions! If you really want to impress
the conference attendees with how big a goiter is, take a picture of it with an
everyday object, such as set of keys. Or, better yet, bring the gross specimen
to the conference and ceremoniously drop it on the table with a loud thud.
I quit using rulers when I realized I never looked at them except to marvel at
how distracting they were. I really don't think any one else looks at them
either. But if you're so anal that I can never convince you to lose the ruler,
do me a favor and shoot just one of your frames on each specimen without it.
I'll guarantee you that nine times out of ten, that's the pic that you're going
to want to show at the conference.
D. Keep the background clean. This is a real pain, but to do otherwise really
compromises the photograph. It is much easier to keep things clean when dealing
with a fixed specimen than a fresh, bloody one. On a related note, try to keep
the camera clean. Layers of dried gore accumulating on the body of a tough
Nikon F3 probably won't hurt the camera, but it tends to gross out certain
people, particularly OSHA inspectors.
E. When photographing lungs or hollow viscera, use inflation- fixed specimens
when possible. You have to resist all sorts of pressure from various circles to
cut up the specimen when it is in the fresh state, but, then again, all great
artists suffer for their work. I have yet to see a gross photograph of
uninflated, unfixed lung that was any good. Inflation fixation of gut segments
delays your diagnosis a day but rewards you with gross photographs that would
bring tears to the eyes of any radiologist.
F. Try to get rid of as much blood as possible. Otherwise, the specimen ends up
being just varying shades of red and pink.
G. Watch out for distracting highlights. Fresh specimens usually have very
shiny surfaces that produce glare. There are several things you can do to cut
the glare on a fresh specimen:
1. Formalin dip for just a few minutes; this preserves color but dulls the
surface; in overnight-fixed specimens which have lost their color, soak in 70%
EtOH to partially recover color.
2. Turn off room lights.
3. Consider changing the lighting situation of your set- up. Nice copy stands
are usually set up with four big floodlights. You may consider turning off the
two on the front of the stand and leave the two on the rear on. Remember to
adjust your exposure to accomodate the loss of these lights.
4. Polarizer/analyzer filters do a great job, but the big polarizers that go
between the floodlights and the subject are very expensive and fade out fairly
H. Photographic backdrops. The choice of a proper backdrop is essential for a
professional looking photograph. The best background is the one no one knows is
there. Several options are available:
1. Transilluminated light board with non-glare glass - expensive; klutzes drop
things on the glass and break it; departmental business manager is incredulous
at expense of replacement and usually stalls its purchase.
2. Wet black velvet - less expensive ($12/yard); reusable for a long time if
you're careful; keep fresh, bloody tissue off! Give each resident his/her own
piece. Of course, if you shoot anything that may have infectious agents on it,
you can't re-use the velvet, unless yuo can find a way to sterilize it (another
argument in favor of shooting only fixed tissue).
3. Water immersion tray - Incredible shots of delicate, "three-dimensional"
objects make you into an amateur Lennart Nilsson; solves problems of gravity
and glare simultaneously for such objects as villous adenomas, chorionic villi,
emphysematous lungs, etc. In my experience, it takes quite a bit of patience to
get a good shot, as undesirable bits of grunge tend to float into the field of
view just as you are releasing the shutter.
4. Towel from surgery - sure sign of an amateur; an embarrassment to say the
least. However, if that's all you've got, ask for a clean towel to replace the
bloody one they handed you the specimen on.
V. COLOR BALANCE
We perceive a sheet of paper illuminated by an incandescent bulb to be just as
white as if it were illuminated by direct sunlight. This goes along with our
concept that "white" light is composed of light of all colors. This is true to
an extent, but various "white" light sources produce their component colors in
varying proportions. For instance, the surface of the sun has a temperature of
about 6000 Kelvins and has much more blue light in it than the radiating
surface of a tungsten filament glowing at 3200 Kelvins, which has more red
light. This relation between temperature of a glowing object and its color is
well known to most people (although not by its scientific name - Wien's First
Law), since we are taught from the fifth grade that a blue flame is hotter than
a red one.
Although the neurological visual processing system behind our eyes compensates
for this variability, the film in a camera cannot. The solution is to make film
where sensitivity to the colors of the spectrum is specifically balanced for
the color distribution of the light source. When shooting in daylight or with
an electronic flash, we need to use "daylight" film. Alternatively, when using
incandescent lights (such as the floods on the copy stand), we need to use
"tungsten" film. This is not some theoretical consideration. If you try to use
daylight film with the floodlights you will get an unacceptably orange picture;
conversely, shooting tungsten film with a flash will produce a picture that
looks like it was painted by Picasso during his "blue" period.
VI. FILM SELECTION
You will select film based on your need for good resolution, your budget, the
necessity of rapid processing turnaround time, and the format in which your
photographic work is to be presented.
A. Color transparency film. These yield the 2" x 2" mounted transparencies
known affectionately as "kodachromes" (in the way that facial tissue is known
as "kleenex"). The actual frame size of the transparency is 24 x 36 mm.
1. E-6 process color reversal film (Ektachrome, Fujichrome). Compared with
Kodachrome (see below), these are expensive; they have quirky color response
(being notoriously poor in rendition of eosinophil granules, which look kind of
dull purple rather than vivid orange), and the slides fade with time (although
this may not be true of newer films in this category). Nevertheless, the E-6
films are by far the most popular in med center settings because of the ready
availability of the E-6 process. Most professionally oriented processors can
routinely turn around the film in four hours. With a readily-available kit, you
can even process these films at home for about US$3 per 24- exposure roll (plus
a one-time US$30 investment for a developing tank and reel).
2. Dye injection film (Kodachrome). Kodachrome is superior in every way to the
E-6 films, except that the processing is slow and is usually done in large
reference centers where the film must be sent. Eosinophils look great, and the
slides last essentially forever if stored properly. It is difficult to find
tungsten versions of Kodachrome, but the daylight versions can be shot under
tungsten illumination if a special filter is used.
B. Color negative film (Kodacolor, Ektar). Also generally available only in
daylight versions, these films yield color negatives which must be printed. It
is preferable to use color negative film for posters, rather than having color
prints made from your transparencies. This is because color prints from
transparencies usually suffer from enhanced contrast that compromises the
accuracy of the rendition. When having color prints processed, you must work
closely with a skilled print processor for good, publication-quality prints.
The automated printing machines used in "one-hour" facilities are not capable
of producing an accurate print from a color negative of scientific subject
(unless, perhaps, it is a portrait of the scientist).
C. Polachrome film. This abomination of a transparency film develops in a few
minutes in a processor you can keep in your desk drawer. It is extremely
expensive, and the dense emulsion makes slides too dark on projection; the
colors are less than impressive. It is best not to let the clinicians know you
have a Polachrome processor. They will start giving you the conference cases
even later and will not realize how lousy the pictures are, while you are
grinding your teeth trying to find that audience- pleasing mitosis somewhere on
D. Black-and-white film. Not to go into this at any length, but you should use
this for originals to be used for publication. Black-and-whites made from color
negatives or transparencies are generally second-rate. Also you can experiment
with color contrast filters, which can really improve results.
Dr. Donald McGavin, Professor of Pathobiology, Univ. of Tennessee College of
Veterinary Medicine, generously provided many fine suggestions from detailed
review of the first version of this paper, and I have incorporated most of them
into the current version. However, the opinions given here are ultimately mine,
as are any errors. I also wish to posthumously thank my father, G. O. Uthman,
who taught me, among many other things, the basics of photography.
Please send any constructive comments about this paper to Ed Uthman,
(email@example.com). I am especially interested in correcting any
errors that may have crept in.
Copyright (c) 1995, Edward O. Uthman. This document may be freely distributed.
It may be reformatted for purposes of compatibility. It may be freely used for
personal and educational purposes, but it may not be used for commercial
purposes without prior written consent of the author. It may be included in
toto or in part as components of other documents with proper attribution.
While I have made every reasonable attempt to include only accurate
information, it is very likely that some of the information is wrong.
Therefore, I am not responsible for anyone's screwing up their pictures because
of a naive belief in everything said here.
Version 2.00, June 30, 1995
>With all those new zooms that don't have depth of field scales, I'm
looking for some help on depth of field. On the lenses that I've used and
looked closely at, it seems that the IR setting on lenses is the same as f8
setting on the depth of field scale. Is this true in general for all lenses?
Since some Canon zooms don't have DOF scales but do have the IR indices at
various focal lengths, IR = f8 is better than nothing.
You can't assume that the IR mark and the f/8 mark are at the same place for
all lenses. I have several lenses in which the IR mark is not near the f/8
mark. The position of the IR mark is going to depend on the design of the
lens, the type of glass used, and so on.
The best way to do what you want is to calculate where the DOF marks should go,
using the formula for hyperfocal distance.
h = f^2 / Nc
h is hyperfocal distance, f is focal length, N is f-stop, c is circle of
confusion (most manufacturers use c=0.03mm for 35mm equipment). When the lens
is focused at h, the two DOF marks are at h/2 and infinity on the distance
scale. For example, for a 50mm lens at f/8, h is 10.4 meters.
[Note, of only theoretical interest: nominally there is a relation between
focal length, DOF mark, and IR mark. Kodak says, if you have no IR mark, try
extending the lens 1/400 of focal length. It's possible to show that this
means the IR-mark should go at the DOF-mark for f-stop N = f/401c, where c is
whatever circle of confusion was used to calculate the DOF scale. If c=.03mm
as is usually true for 35mm, the IR-mark goes at N = f/12. So a 50mm lens
would have an IR-mark around f/4, a 100 mm lens would have it around f/8, etc.
I looked at a few lenses and this seemed to work OK for non-exotic prime
lenses, but didn't work too well for the two zooms I own. Which means the
Kodak recommendation isn't likely to work for zooms - makes sense given their
more complicated design.]
From: firstname.lastname@example.org (Ben Weiner)
Organization: Rutgers University
>In a recent messsage Graeme@zone5.demon.co.uk mentions divided development with
>D23 to get long scale negatives (ie with 14 tone steps). In the ancient past I
>used D23 with Plus X, and it did indeed produce a very long scale negative. I
>have two questions that I hope someone out there can answer: 1. Does anyone
>have a time/temperature for developing Tmax 100 and/or Tmax 400 in D23?
>2. What is divided development, and how is it used with D23?
Split the D-23 as follows:
Bath A start with 750ml water
7.5 g Metol
Sodium sulphite (sulfite) 80g
Sodium Bisulphite 20g
Cold water to make 1 litre
Bath B start with 750ml water
15g Kodalk (balanced alkali)
Water to make 1 litre
I develop in bath A for for 4 mins and bath B for 4 mins (FP4+ sheet). Minimal
agitation in bath B. Experiment, I use Cold Cathode. If you don't see any
postings about Tmax post me.
Loads of references to this in Ansel Adams 'The Negative'. Old Photobooks and
of course that marvellous book that should be on eveyones shelf The Darkroom
Cookbook by Steve Anchel.
Graeme, Graeme@zone5.demon.co.uk (Graeme Webb)
Subject: Re: HELP: Lenticular Photography (XOGRAPHY)
Date: 10 Aug 1995 03:12:43 GMT
Organization: Rochester Institute of Technology
Xref: isc-newsserver.isc.rit.edu rec.photo.advanced:23232 rec.photo.darkroom:798
9 rec.photo.help:17223 rec.photo.misc:22221
In article , email@example.com (Eric Rayboy) writes:
>Does anyone have info on lenticular photography (sometimes called xography)?
>This is the process of making 3D pictures using a plastic lens over the
>finished product (like the NIMSLO of a few years back). I am seeking books or
>articles on how it is accomplished.
Essentially you take two pictures and slice them up into narrow vertical
strips. Then you discard every other strip of each of the pictures. Then
you place the stips of one in between the strips of the other, in order.
Then you overlay a lenticular screen of the correct design such that at a
given distance your left eye "sees" only one set of strips and the other
sees the other set of strips. If the pictures are a stereo pair you see an
image exhibiting depth.
Instead of a lenticular screen you can also use a "barrier strip", made up
of alternating dark and clear strips. The frequency of these is related to
the frequency of the picture strips, the distance from the barrier strips
to the picture elements and the viewing distance (and the eye separation of
The placement of the image strips behind a lenticular (or barrier) strip
can also be done optically as was done by Nishika Labs for Nimslo-format
prints made up of 4 (!) separate images per scene, and as is still done by
Image-Tech for the three-view stereo images. Kodak also markets a system
called Depth Imaging which uses a significantly more coarse lenticular
screen than Image Tech or Nishika do (did) but where the individual images
behind each strip are computer manipulated for enhanced separation and/or
this is _roughly_ correct i hope ...
andy o o 0 0 o o Andrew Davidhazy, at RIT's Imaging and Photo Tech Dept
\/\/\/\/\/\/ firstname.lastname@example.org High Speed Photography Lab
>I am going to photograph some lasers, and I was wondering if any one has done
>this before and how long should I leave the shutter open in darkness. Also I
>was thinking of dropping dryice smoke stuff over the laser's beam so that it
>shows up on film, or should I use smoke of some sort?
Depends-- you might just consider that you are going to "blow-out" the laser
line, give it 1-2 sec. at an aperture which will give you the DOF you need. I
have done it this way. But, if the truth comes out, I also pulled a Paranoid to
check the exposure.
I have used a Rosco smoke machine, cuz I have one sitting in the closet, but
when that was inconvenient, I have used Diffuse-It Cloud Spray. It should be
available at any reasonably well stocked pro camera supply. Calumet P/N is
DT5000. Costs less than $10 and much easier to use than dry ice. Also consider
other aerosol sprays. I have tried hairspray, flour, water in a mister, etc.
OBTW, you might want to consider exposing the laser(s) separately from the
subject. Old tabletop guy's trick.
Jim Hartmann, email@example.com
Since the beam itself is invisible you need something in the air to make it
show up. If there are enough particles in the air sometimes a long exposure is
enough. Depending on the air cleanliness.
I often have to photograph in laser labs to show the people and the work they
are doing and want the laser in the image as well. I set up the flash units to
light the scene however I want but try to hit a fstop around f8 ( I use ISO
100 film). I set the camera to the bulb setting and in total darkness expose
by firing the camera and flash and holding for an exposure time of 10 - 12
seconds on average.The flash exposes the scene and the time exposure allows
the laser to image as well as that glow they often give off. Season to taste
with longer and shorter exposures. Often the beam is visible in the photos.
If the beam is my primary goal I appraoch it slightly differently. I have used
smoke ( I only smoke for my art you understand ), dry ice and an aerosol
called "Diffusion - cloud in a can". This stuff was ungodly expensive and
environmentally hostile but hung in the air for quite a while. No longer
available in Canada so I have no soul searching to do regarding using it.
This diffusion spray and cigarette smoke may not make you popular. If this
laser is on a large bench setup these materials may deposit a film on mirrors
and photodiodes that can be tedious/difficult to clean. Try this:
Set up the camera and set it to bulb. Paint the beam with the dry ice fog as
even as you can for as long as it takes or my favourite way - use a white card
or the card researchers use to detect beams and paint the beam with it. Lock
the camera on time exposure and hold a white card angled slightly to the lens
in the beam so the laser images as a bright dot. Now just move it along the
beam. In total darkness the exposure is however long it takes to paint the
beam. It looks like a rod of light or if a pulse laser it can even be a beam
of dots it you time it right. You can paint all sections of the beam and have
someone else help you at the same time. Usually with ISO 100 at f8 and Polaroid
Best look and make sure to leave no residue or film on the laser equipment!
Harry Turner National Research Council Canada Harry.Turner@nrc.ca
33.03 -< UK Company that makes microscope (and other?) adapers >-
>I am looking for a pentax k-mount microscope adapter that with a 31mm barrel.
>Does anyone know of any vendors that might have such an animal.
There is a company in the UK who will make any microscope adaptor -
They are reliable, and charge about £40. Takes a couple of months.
Ian R Broomhead
SRB Film Service
286 Leagreave Road
Beds LU3 1RB
John, firstname.lastname@example.org (John Marriage)
33.04 -< Improvised Contrast Control filters from Rosco materials >-
>Our Besseler 23C-II's take the large filters, and we do not want to use
>filters below the lens; however, we only use 3,4, and 5 filters and can't
>afford to buy whole sets just to get them. Does anyone have a source for
>filter material, perhaps sheets we can cut down?
In the Jan 1993 issue of ViewCamera, Joseph Englander suggested the following
Rosco filters to form a useful variable contrast series for larger formats.
The filters probably will not give equal or 2x exposure times for an average
zone 5 density. For consistency, the filter factors should be worked out by
determining minimum times to dmax for each filter and each paper. Most of the
filters sold specifically for variable contrast papers have neutral density
built in to equalize exposures which isn't the case with lighting or color
correction/conversion filters. From low to high contrast:
3107 Tough Yellow Y-1
389 Chroma Green
3304 Tough Plusgreen 30G
3315 Tough Half Plusgreen 15G
3313 Tough Half Minusgreen 15M
3308 Tough Minusgreen (Magenta) 30M or Roscolux 37 30M
3202 Full Blue (Tough Blue) 80A
68 Sky Blue
Rosco: 36 Bush Ave., Port Chester, NY or 1135 N. Highland Ave., Hollywood, CA.
From: bg174@FreeNet.Carleton.CA (Michael Gudzinowicz)
33.05 -< Reducing overexposed IR film and others too >-
>re: reducing what appears overexposed IR films ...don't if you don't have to!
This is very good advice, especially the first sentence! However, if you need
to reduce (more), I would not keep the film on the reel. Two reasons: 1>
Reduction is a gradual processs, but it speeds up exponentially. You need to
be able to see what it is doing and be able to stop it fast!! 2> It may be
that not all the negs on the roll need reduction, and this kind of shotgun
approach (reducing film on a reel) could reduce negs which don't need it, and
once that is done, IT'S DONE!
Here is what has worked for me: Develop, fix, wash, and dry your infra red
film as normal. Go ahead and cut & sleeve it if you like. Note that infra red
film often appears very overexposed compared to standard pan film, but will
print o.k. Try to make a small enlargement before you do any reducing. If it
still is too dense, use this formula:
STOCK SOLUTION A,
Potassium ferricyanide, anhydrous 2 tablespoons + 1 teaspoon
Water to make 16 ounces
Stock SOLUTION B
Normal dilution of non-hardening fixer 2 quarts
Store each solution seperately. They keep for months, but should be used right
after mixing. FOR USE: Mix 30 milliliters of solution A with 120 milliliters
of solution B and add water to make 1 liter of working solution.
Pour the solution in a white tray under a good light source. Drop in the negs
to reduce and agitate for 30 seconds. Pull out the neg and rinse with water,
hold it up to a light and check the density. Go in the solution again if it
needs it, but check it as much as possible to avoid over reducing, which is
uncorrectable. Fix it, wash it, and dry it as usual.
Russ Rosener, email@example.com
33.06 -< Tips for photographing the sun >-
>Can anyone recomend filters for shooting the sun? I'll be using a 500mm
>mirror lens with an option for 2X converter as well.
A Kodak Wratten Neutral Density filter ND4. Use 1/500 second at F11-F16 with
100 ASA film. An ND4 filter is not the same as 4x. ND4 is 10 to the power of
4, ie. 10000 times intensity reduction. This is the cheapest way to get a good
Alternatively at sunset when the sun is touching the horizon, 1/1000 at f22
with no filter works well. The atmosphere does the filtering.
Safety Note: The filter goes between the sun and the lens not between the lens
and the camera. The filter lets through levels of UV and IR which can damage
your eyes. That said, I've been using mine for 15 years. Just focus and frame
without wasting time. If you spend lots of time looking through it then you may
sustain eye damage. A No 14 welders filter is a safe visual filter. These cost
$2. You can safely focus and view through one of these then switch to the ND
filter. The welders filter is unsuitable for photographic use.
Joseph A. Cali, Research School of Earth, email firstname.lastname@example.org
Australian National University, Canberra 0200 Australia
note: the size of the image of the sun's disc at the film plane is roughly
equal to 1/100 of the focal length of the lens used on the camera. A 500 mm
lens will make an image that is about 1/5th the short dimension of the film
or enlargment. (24mm divided by 5mm = about 1/5) this was added here by andy,
33.07 -< Stage Photography Recommendations >-
>I'm going to be shooting a stage production in the near future on 400 speed
>film. I would be pleased to get any suggestions or hints y'all might have.
I assume you're talking about shooting color negative film, since you mention
ISO 400 and are concerned about color rendition? (If you were shooting slide
film, selection would be easy since there are only two choice: Kodak Ektachrome
320T -- nice image quality but slowish -- or Scotch 640T -- grainier, more
muted colors, but a stop faster.)
For print films -- especially with the fairly slow lenses you plan to use -- I
wouldn't even bother with 400-speed films; I'd go straight to Fuji Super G 800.
This film has very nice grain and color rendition. Still more important is that
it has moderate contrast -- this is important in stage photography, since the
lighting is usually quite contrasty. (For example, although I like Kodak's Gold
1000 and Ektapress 1600 films, they're both contrastier than the Fuji film and
can get hard to manage under theater lights.)
Your biggest problem with color rendition is going to be that stage lights are
tungsten, but all 35mm color neg films are daylight balanced. That means your
pictures will have an inherent yellow-orange cast. The lab that prints the
negatives can correct this for you, but may have trouble knowing how much
correction to apply since they didn't see the original show! Ideally, you'd
shoot a gray card under the stage lights to give them a reference point; if you
can't do that, try to get some close-up shots of the actors showing skin tones.
Then, be sure to tell the lab that you shot the film under tungsten light. It
may take a couple of tries to get color balance that corresponds to your memory
of what the scene actually looked like. (This is why I prefer to shoot slide
film or b&w!)
As to general technique: Use a spot- or center-weighted meter if your camera
has one; otherwise the dark areas around the main subjects will cause the meter
to give too much exposure. (The difference in brightness between the subject
and background is greater than it looks to the eye; lighting designers cleverly
set it up this way to subtly focus attention on the performers!) With a
center-weighted meter, you may have to give a bit less exposure than the meter
suggests -- for negative film, I'd try about -1/3 or -2/3 stops of exposure
compensation. (If your camera doesn't have a spot meter, and you plan to do
much stage photography, eventually you'll probably want to break down and buy a
separate 1-degree spotmeter.)
You'll probably be sorry that your fastest lens maxes out at f/3.5. If you
happened to buy a 50mm normal lens with your camera -- an f/1.8 or f/1.4 or
something -- take it along, too; it doesn't take up much space in the bag, and
can really save your bacon if you want a nice overall shot of a dimly lighted
scene. (Since I photograph a lot of ballet productions, I've had to invest in a
lot of fast lenses so I can get action-stopping shutter speeds: the ones I use
most often are an 85mm f/1.4, a 100mm f/2, a 200mm f/2.8, and for smaller
theaters a 50mm f/1.4 or 50mm f/0.95 -- yes, the latter is a fairly exotic
item! If you keep doing a lot of stage stuff you may want to invest in at least
a fast medium tele such as an 85~100mm f/2 or so; this also makes a nice
The tripod is a good idea, although banging it around as you climb up on
catwalks etc. may get annoying. I've tried various other strategies for
steadying the camera while allowing mobility. Sometimes I use a monopod,
especially for shows where I have to stand up to get a good view of the stage.
Often, though, the best solution is to brace either my arms or the camera
itself on the back of a theater seat (obviously this only works if you're
shooting a rehearsal; at a performance, the person occupying the seat may
object!) Backstage or on the catwalks, look around for things against which you
can brace the camera (walls, railings etc.) -- this can often help steadiness a
lot. Just don't lean on stage or lighting equipment that might move, vibrate,
burn you, fall over, etc.! If in doubt, ask the stage manager what's safe and
Hope some of these ideas help. Good luck and have fun!
From: email@example.com (Jim Williams)
33.08 -< Photographing Soccer Recommendations >-
>I am having a hard time shooting Soccer games. Where would be the best place
>on the field to get players in action and what lens would be best?
In my opinion the best place generally is at either end of the field, somewhere
between the goalpost and the corner of the filed but closer to the goal. Try to
get as close to the goal line as allowed (without interfering with the play).
There is generally lots of action in the area just in front of the goal and you
should be able to "reach out" for close to frame filling shots of the players
with something like a 135 or 200mm lens. Hold camera horizontal when players
are far and turn it vertical when closer-up. While a zoom may be useful single
focal length lenses have been used for many years before the zooms arrived.
33.09 -< Sprint Photographic Chemicals >-
>I have been in camera stores in Ohio, upstate New York, and in southern New
>England and have never seen the stuff. Where can I get Sprint to try it?
We have been using Sprint as our basic b&w chemistry for a number of years and
are very happy with it. We buy it directly from Sprint:
Sprint Photo Chemistry, 100 Dexter St., Pawtucket, RI, 02860
phone: 1-800-356-5073 fax 401-728-0913
Professor Steven P. Mosch, Photography Department Chair
Savannah College of Art & Design, 101 Martin Luther King, Jr. Blvd.
Savannah, GA 31402-3146 Phone: 912-238-2469 Fax: 912-238-2436
Sprint chemistry is sold through The Maine Photographic Reource 1-800-227-1541
or directly from Sprint fax: 401-728-0913
33.10 -< Artcraft Chemicals - Photo Chemicals Supplier >-
Photographers Fromulary is good, but Artcraft Chemicals will sell you the same
materials for lower (30-40%) prices. He does not have Tech Pan kits, but
carries the chemistry to make up Tech Pan developers. ARTCRAFT CHEMICAL P.O.
BOX 583 * SCHENECTADY, NY 12301 * 800-682-1730 * or 518-355-8700. Ask for a
catalogue and tell Mike Lacobson Maxim sent you .
33.11 -< A few non-US magazine recommendations >-
Here are some non-US photography related magazines recommended by a couple of
PhotoForum subscribers, Peter Marshall and James McArdle:
Creative Camera : subscriptions: Cornerhouse Publications, 70 Oxford St,
Manchester M1 5NH, England "a credible, thinking, image-led photography
magazine" USA 50$ per year (institutions 72$) - six issues.
Inscape: William Bishop, 22a Gladwell Rd, London N8 9AA, England. Outside
Europe #15 (international Postal Order or UK cheque) for 5 issues
Camera Austria: Forum Stadtpark, Stadtpark 1, A-8010 Graz, Austria
4 issues AS600 /DM25 /US$ 18.50 This is probably the best of the European
magazines. Like several others it is largely bilingual (German/English).
The following addresses are from some old issues of Perspektief:
Cliches: 36 Rue de Houblon, 1000, BRUSSELS, Belgium
Contretype: 103 rue d'Espagne, 1060 BRUSELS, Belgium
Focus: Utrectsestraat 131 / postbus 15436, 1001MK, Amsterdam, Holland
Foto: Larixlaan 6 / postbus 3, 3830 AA Leusden, Holland
Fotogeschichte: FICHARDSTRASSE 52, D-6000, Frankfurt 1, Germany
Fotografiska Museet: Box 16382, S-103 27, Stockholm, Sweden
GKf- Bulletin: Nieuwe Keizersegracht 58, 1018 DT, Amsterdam, Holland
History of Photography: Taylor & Francis Ltd, 4 John St, London WC1N 2ET, UK
Photographie Ouverte: Ave. Paul Pasteur 11, B-6100 Charleroi/Montsur-M, Belgium
Photovision: Arte y Proyectos Editoriales, S.L., P.O.Box 164, 41710 - Utrera,
and from J. McArdle:
Here are some European magazines.
BEELDING Netherlands ; Maanblad voor kunsten P.O. Box 13097, 2501 EB Den Haag.
10 copies p.a., Hfl 50
BILDTIDNINGEN; Sweden Fotograficentrum, P.O. Box 15310, Stockholm, S-104 65
Brennpunkt; Germany, Berlin Magazin fur Fotographie, Ed., DIBU/LV Berlin im
VDAV, red: Waghauseler Str. 8, 1000 Berlin 31
Camera International France, 51, rue de l'Admiral Mouchez, 75013 Paris
European Photography, Germany ed. Andreas Muhler-Pohle, P.O. Box 3043, D -
3400 Gottingen (main texts in English as well as German)
la Recherche Photographique, France Paris Audiovisuel, 35 rue de la Boetie,
the Photographic Journal; Britain Royal Photographic Society, ed. Roy Green,
The Octagon, Milsom st, Bath, Avon BA1 IDN
Perspektief; Netherlands Centrum voor Fotographie, Sint - Jobsweg 30, 3024 EJ
Rotterdam (main texts in English as well Dutch)
Katalog; Denmark, Kvartalstidsskrift for fotografi, Museet for Fotokunst /
Brandts Klaedefabrik, Brandts Passage 37 & 43, DK - 5000 Odense C
even if you can't read the writing you can read the photographs!
Portfolio - published quarterly and is cheap - 18 Pounds subscription -
Photography Workshop (Edinburgh) Limited, 43 Candlemaker Row, Edinburgh
Scotland EH1 2QB Tel 031 220 1911 Fax 031 226 4287
Photofile - published by the Australian Centre for Photography 3 times a year
and welcomes articles, publishes reviews of Australian photomedia - address:
257 Oxford St., Paddington, NSW 2021 Australia. subscription-tel: 02 331 6253
Platinum Portfolio - quarterly - PO Box 184 Artarmon NSW 2064 Australia.
Metro Education - devoted to Media Education but of interest especially to
teachers of photography - ATOM P.O. Box 222, Carlton South, Victoria,
Australia 3053 , tel 03 482 2393, fax 03 482 5018
I know there are excellent photomags in South America and in Asia which I've
seen in passing - I'd love to get more information on these - can anyone help?
Regards James McArdle, Photography Lecturer, Latrobe University, Bendigo PO Box
199, Bendigo, Australia 3550 e-mail: firstname.lastname@example.org
=========================== end of section 33 ==============================
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