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FAQ or Answers to Frequently Asked Questions Section 30
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Please check "root" (faq$txt) file for acknowledgements.
This is a file containing answers, tips, hints and guidelines associated
with recurring questions asked by photographers. If you would like to
add a tidbit of knowledge to this list just send it to ANDPPH@rit.edu
who will gladly add it to this collection. For complete table of content
send message to ritphoto@rit.edu with FAQ$txt in the Subject: line
These files are available in SECTIONS.
This is Section 30 and its contents are listed below.
30.1 -< Making Masks to Make Money w/ Trading Cards >-
30.2 -< More Wedding Photography Tips >-
30.3 -< Photo Archives of an old Photo Discussion list >-
30.4 -< 8mm and 16mm film source and brief movie primer >-
30.5 -< Pinhole Cameras and Supplies Source >-
30.6 -< What shutter speed to STOP motion? >-
30.7 -< Filter to make color scene look as B&W sees it! >-
30.8 -< Polarizers for Infrared Photography - Q&A >-
30.9 -< What makes a macro photograph? >-
30.10 -< Making B&W slides from B&W negatives >-
30.11 -< Photo Attractions in Boston, Chicago, Las Vegas & Mobile >-
30.12 -< Favorite Textbooks of PhotoForum readers >-
30.13 -< The Argyrotype Process >-
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Note 30.1 -< Making Masks to Make Money w/ Trading Cards >-
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>Anyway my idea is this, Print out the text and symbols for whatever masks
>I'd like to create using standard White Paper and a Laserjet printer. Then
>using a Copy stand and Kodalith Film make a mask which I can then sandwich
>with a negative and print as usual. Seems like a GREAT way to make Trading
>Cards for Little League teams and such. So am I completely DAFT or is this
>a feaseable idea? What speed is Kodalith available in? How difficult to
>process is it?
You can start your exposure tests at ISO 8 under tungsten lights, with the
film processed in Kodalith developer, and ISO 25 processed in D-11.
Sheet film processing can be done in trays, and can be done under a red
safelight (Kodak 1a), so you can see a little of what you are doing.
Agitation should be continuous and development time is 2.75 minutes for
Kodalith developer and 2.5 minutes for D-11. Make your trial exposure
readings from an 18-percent gray card.
If you are shooting the 35mm film, you can load the film on reels and then
agitate continuously in the tank for the same times.
Consider creating your computer artwork at the largest size your printer
can produce (so a trading card would fill as much of a letter size page as
possible, for example), include black boxes where the photo will go (to
create a transparent "window" on the Kodalith film), and then shoot to the
size you need on sheet film, or to the appropriate size for enlarging from
35mm film. The result will be a higher resolution from your laser printer
than you would get if you created your artwork at actual size.
Best of luck to you.
~NORM
- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
NORMAN LENBURG, Photo/Imaging Instructor
Madison Area Technical College
3550 Anderson St., Madison, WI 53704 USA trans-121
608-246-6521 (office), 608-246-6880 (fax)
...............................................................................
>Anyway my idea is this, Print out the text and symbols for whatever masks
>I'dlike to create using standard White Paper and a Laserjet printer. Then
>using a Copy stand and Kodalith Film make a mask which I can then sandwich
>with a negative and print as usual. Seems like a GREAT way to make Trading
>Cards for Little League teams and such. What speed is Kodalith available in?
>How difficult to process is it?
That is probably exactly how the masks you bought were made although I'd
think that the type was typeset and the graphics were reduced from some
significant sized original. The masks generally are used as contact masks
placed on your print during enlarging instead of masks to be used in the
enlarger. Whether a laserjet generated original is acceptable in terms of
edge quality is something you and your customers will have to decide.
Kodalith is pretty slow material, much like photographic paper. It can be
processed under a red, 1A, safelight. The chemicals tend to be significantly
more active than D-72 but if you can do prints you should not have much
trouble with Kodalith. One thing to watch for is pinholes that show up due
to dust in the black areas. These can be avoided by careful darkroom
technique or by using an opaqueing product ... dense black or red water
based dye or "paint".
andy o o 0 0 o o Andrew Davidhazy, at RIT's Imaging and Photo Tech Dept
\/\/\/\/\/\/ andpph@rit.edu High Speed Photography Lab
________| |__________________________________________________________
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Note 30.2 -< More Wedding Photography Tips >-
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>I will be shooting my first wedding soon. I was wondering if someone could
>point me to a site on the web or anywhere for some pointers, FAQ's, advice?
I recommend reading as many books on wedding photography as possible.
Also go out and look at other wedding photographers work to get a feel
for types of poses to use as a starting point.
Put together a photo wish list with the bride and groom. For example
formal poses of the bride with the parents and family members and other
single, couple, and group shoots. Have the bride gather some example
photographs she wants out of bridal magazines.
Then do a couple of dry runs. Go to the wedding/reception locations and
take some photographs of the wedding couple. Practice some of the poses
and watch the backgrounds. Look for good interior locations (wooden
stairways, hallways with french doors etc.) in the event of bad weather
forces the wedding indoors. One thing I like to do is have only one ear
(per subject) showing towards the camera, take a look at some wedding
photographs and you will see what I mean. Also when the lighting will
only produce a good photograph for either the bride or the groom shoot
the bride in the best light.
Notice the light levels during your dry runs and decide which film speed
is better suited for the location. Also determine what lenses are needed
or better suited per location. You might want to try out some soft
lighting effect filters while you have the chance. And no matter what
keep notes on locations and exposures and flash settings, this is very
important.
On the wedding day be sure to bring at least two cameras (one as a back
up to the other) with fresh batteries and have some spare ones in the
camera bag. During the wedding try to use both cameras for the important
shots in the event one camera is having unforseen problems. Bring
enough film to take 720 pictures. While most weddings will only use
about 240 to 360 exposures you should always bring enough to cover the
wedding twice over. It is better to have to much film than not enough.
At the wedding don't be afraid of running out of film and don't forget to
take more than one frame per pose, try about three per pose as a starting
point. This in case some is blinking their eyes during the exposure.
If you are shooting 35mm I recommend ten rolls of VPS or NPS (160 ASA)
and ten rolls of PMC or NHG (400 ASA). You should try out a roll of each
and decide which gives you the colors you like. You might want to try
derating the film to a lower ASA for better shadow detail and a whiter
dress. Pass the samples by the couple for their input. This will also
allow you to check your camera equipment, walking the shutter and f/stop
combinations to make sure everything is working.
Be sure to use your flash whenever it is required, when in doubt take a
shot with and without the flash. Try to get a hold of a flash bracket
and flash extension cord to place the flash high oer the camera, to
prevent red eye and to throw the shadows down behind the subject instead
of on the background.
Don't forget the wedding group shot of the entire wedding party guests
and all, the best time for this shot is at the best mans toast. Have
everybody turn and face the camera and raise their glasses to the bride
and groom. You should be on a high location allowing you to shot
downwards at the party.
I recommend that you recommend to the wedding couple the use of Kodaks
wedding cameras, to be placed on the tables at the reception. This will
help cover the wedding reception events.
At the wedding remember to shoot the behind the scenes events like the
best man and groom straighten out the grooms tux or ties. Or the Mother
of the bride with the bride helping the bride with her dress or brushing
her hair. Another good shot is the bride with her father just before
they start the walk, maybe him giving her advice or kind words before
giving her away.
Bottom line go beyond the average stuff you see in the wedding albums.
You are taking pictures for them to help them remember the one special
day in their lives. Don't be afraid have fun.
Good luck,
Don
From: Don Farra
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Note 30.3 -< Photo Archives of an old Photo Discussion list >-
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There is, in regard to other sources, a digest of photography info at
ftp.nevada.edu in the pub/photo directory.
From: Marshall Kragen
(these seem to be archives of the old "photography phorum" mailing list)
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Note 30.4 -< 8mm and 16mm film source and brief movie primer >-
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>Does anyone know where to get 8mm and 16mm film cameras and film? Also
info on use of such camera would be appreciated.
I recommend you call Chambless Cine Equipment in Atlanta, 706 636 5210,
and get their catalog. The value of this catalog is that it's an
extensive description of most cameras, lenses, and accessories
available on both the used and new market for 8 and 16mm moviemaking.
You can buy directly from them--they're reliable, but their prices are
naturally high since they market to professionals. Equipment can be
picked up at camera shows --there's one in Fort Washington at the Expo
Center on June 4, for example. Local camera dealers also have this
stuff from time to time; try Fotorama, 1831 Chestnut in Phila. or
PhotoCine on 18th St. These dealers and fleamarketeers don't know much
about cine equipment so you have to do some homework to get what you
need. The upside is that prices can be quite low since these guys are
anxious to get rid of this stuff; the market for movie equip is thin.
You can get good old cameras (early 1950s; I'd avoid prewar stuff),
often with several good old lenses, for a couple hundred dollars and in
my experience these simpler cameras are better for learning how to film
than the later, overly automated ones. This includes nonreflex Bolex
cameras, Bell and Howell 70 series (the 70DR is still in production
but can be got used at a flea market for $150 or so) and the Kodak
Cine Special II and K-100, my personal favorites. >so how do you
determine exposures when doing movies?
Exposure in cine cameras is controlled through lens aperture, filming
speed (frames per second) and degree of shutter opening. Simpler
cameras have fixed shutters--they don't have control of the degree of
shutter opening, although some old 8mm cameras have it, strangely
enough. Changing the shutter opening is rarely used as a way of
controlling exposure; it's primarily a way of "fading" in and out--you
know the effect. without fades, scene changes are abrupt. One thing
about movie making that surprised me is that the adjustment part of the
process--fiddling with aperture, focus, etc. is a lot simpler than
with still pictures. Focus is easy with 16 and 8mm movies since you're
using very short focal length lenses. The normal lens for 8mm is 12.5mm
and for 16mm, 25mm. These are "wideangle" lenses by 35mm standards and
have great depth of field. About all you really need to worry about is
aperture, and that's no big deal. In the late 50s, consumer 8mm and
super8 cameras often had automatic aperture control. In my experience,
this is mostly a pain in the neck. It acts very slowly, so a lot of
scenes are ruined by transitions in aperture. And, in some cameras you
can't defeat it, so when the meter gives out--and they always do
eventually--the camera is a useless piece of junk. (These later cameras
are rarely worth paying someone to fix, and nearly impossible to fix
yourself.) With a good movie camera, even with manual aperture control,
you can concentrate mostly on creating good scenes--which of course is
not so easy. Zoom lenses-- not worth the extra money in my opinion
unless you're really committed to buying yourself a new, pro outfit.
Earlier, used zooms are not as sharp as fixed focallength lenses, and
the fixed lenses can be picked up cheaper. Zooming while shooting is a
nearly useless effect, and since the lens is mostly going to be at one
focal length while shooting, why not use separate lenses?
BTW ... normal filming speed for silent movies is 16 frames per second
(since the 1950s texts say 18 frames per second) and 24 frames per
second for sound movies. The higher speed for sound is principally to
improve sound fidelity, just as faster speeds on a tape recorder sound
better. This is why old silent movies look jerky--they are projected on
sound projectors too fast. Anyhow, most cameras permit a variety of
speeds from about 8 frames per second sometimes up to 64. Filming
faster than the norm (more than 16 for silent films) produces "slow
motion" effects when projected at normal speed, and filming slower
produces the effect of watches and clocks speeding up, etc.
Chambless Cine Equipment
Route 1 Box 1595
Highway 52 West
Ellijay, GA 30450-9723
Ph: (706) 636-5210
Fx: (706) 636 5211
.... the item above was composed by JJMcF@aol.com and posted on rec.photo
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Note 30.5 -< Pinhole Cameras and Supplies Source >-
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I have a 4x5 pinhole camera that I recently purchased from the Pinhole
Resource. I'm almost positive that they make several 8x10 cameras as
well. Their design would allow you to use standard 8x10 film holders
and 8x10 polaroid holders, ( if you really like to spend money! ) which
makes it rather convenient for field use. Their address is:
Pinhole Resource
Star Route 15, Box 1355
San Lorenzo, NM 88041
(505) 536-9942
They also offer books, a newsletter, exposure calculators, and other
miscellaneous pinhole stuff.
From: Pietr
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Note 30.6 -< What shutter speed to STOP motion? >-
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There was a question related to determination of the shutter speed
required to make a sharp picture of a race car what would be the
exposure time required to achieve a sharp photograph? Consider this:
From: Grover Larkins, larkinsg@solix.fiu.edu
Florida International Univeristy
******************************************************************************
At 90 degrees between Car's direction and Camera's Optical Axis:
Race Car --
Length = 5 meters,
Width = 2 meters,
Speed is 80 meters/sec.
Image Size in Camera = percent of viewfinder occupied at time of
shutter release X 36mm
Magnification is = (Image Size in Camera)/(1000 X Length of Car) -- for example
use Image size in Camera = 18mm
Max Allowable Blur is 1/40 mm for 35mm format (somewhat arbitrary but <1/30 mm)
Max Allowable Blur = (Speed in m/sec)X(Magnif)X(Shutter Time in sec)X(1000 mm/m)
Hence:
Shutter Time = (Max Allow. Blur)/((Speed in m/s)X(Magnif.)X(1000 mm/m))
******************************************************************************
If Car's Direction and Optical Axis are Co-Linear:
(Assumption that the Car is far from the Camera)
Init. Magnification = M1 -- for the example use M1 is 0.009
M1= (Width of Car in Viewfinder in mm)/((Width of Car in m) X 1000mm/m)
Dist. When Shutter Starts = d1 -- for the example use 100m
Dist When Shutter Stops = d2
delta t = t2-t1 = Shutter time
d2 = d1 +/- (delta t in sec)X(Speed of Car in m/sec)
Note: Plus for going away, minus for approaching the camera
M2=(1+/-(Speed of Car in m/sec)X(delta t in sec)/(d1-fl of lens in meters))x(M1)
Note: Since d1 and d2 >> fl we can ignore fl in the above.
Max. Allow. Blur > (M2-M1)X(Width of Car in m)X(1000mm/m)
delta t<+/-(Max Blur mm)X(d1 in m)/((Speed in m/sec)X(1000XM1)X(Car Width in m))
-------------------------------------------------------------------------------
Answers:
90 degrees with 50% of viewfinder => 1/11520 sec or less for shutter time
Co-Linear=> 1/520 sec or less for shutter time
Hope this Sheds some Light on the Problem,
Grover Larkins, larkinsg@solix.fiu.edu
Florida International Univeristy
PS -- Hummingbird Wings at 1/5 lifesize and 60 beats/sec require ~1/20,000 sec.
================================================================================
From: bg174@FreeNet.Carleton.CA (Michael Gudzinowicz)
>I'm looking for general rules of thumb for shutter speeds to stop motion ...
The other posts contain definitive answers, so I'll offer a "rule of thumb"
and its derivation.
Simply determine the time it takes the subject to cross the frame, and divide
by 1200 to determine the shutter speed for small (5X-8X) prints. If you can't
determine the time (too fast), use the fastest speed possible and pan.
Let's assume that a 0.030 mm blur of the circle of confusion is acceptable for
an 8X enlargement (borderline). The velocity (v) of the image to moving on the
film in mm/sec is equal is the time to cross the frame divided by 36 mm.
The time to move 0.03 mm is 0.03 / v
or 0.03 * ((time to move across the frame) / 36)
or (time to move across the frame) / 1200.
For larger prints, use a smaller blur value, such as 0.015 which gives (time
across frame) / 2400 for the shutter speed. For subjects with "moving parts",
such as a person walking, consider relative motion of the "parts" (legs & arms)
which might be 2X fater than the "average" speed.
With objects moving toward or away from you, you'll have to estimate the rate
of change of magnification, or a rate to fill the frame. For a small object
relative to frame size whose rate of change of size is small, shutter speed may
not be that important. If the photo is taken during the period when an object
goes from 1/2 to frame filling size, the time to do so may be considered 1/4 of
the frame travel time above (note, the distance at the object's edge traverses
is 1/4 the frame size as it goes from 1/2 frame to full frame size. In this
case, the time to go from 1/2 to full frame would be divided by 300 rather
than 1200, though 1200 could still be used to be "safe".
The same simple approach can be used to estimate deliberate blur of a moving
object. If you want it blurred for 1/8 the distance across the print (or
negative), exposed at 1/8 the speed which it takes the object to cross the
frame. To blur the background over 1/8 of the frame, use the same speed but
pan.
If you're at Indy, with cars going by at 220 mph or 322 feet per sec, you can
"guess" the frame travel time by dividing the field of view (in feet) of your
lens at the subject by 322... with a tele fast speeds and panning are
necessary, and always pre-focus.
-- Mike -- ab366@osfn.rhilinet.gov
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from: andpph@rit.edu (Andrew Davidhazy)
In several articles related to stopping motion the magnification factor was
invariably included in the determiantion of the necessry shutter speed to
achieve a particular degree of sharpness. I would like to add to the discussion
an observation that while including magnification as a factor may be ok it can
lead to misconceptions in terms of recording "detail" in the subject.
It does no good (sort of) to achieve a sharp image if the image is so small
that one can not see it! ... which is the inevitable result of trying to
photograph a fast moving subject with a slow shutter speed and using as a
controlling factor the magnification of the image by either moving back from a
subject or using a shorter focal length lens.
I think it may appropriate to also think about required exposure time by
simply deciding how much blur can be tolerated _at the subject_ (one then has
to be careful about specifying what part of the subject is the true subject,
like is all of it what one is interested in or a small part of it). It seems to
me that if you decide allowable shutter speed in terms of the subject size
magnification becomes irrelevant and what you will want to use in fact is the
largest possible magnification to keep emulsion "noise" down.
Basically what I am thinking is that it makes no sense to photograph with a
short focal length lens if later on one will enlarge the image to the same size
it would have been with a longer one.
Don't get me wrong, either approach will work but in terms of resolvable detail
it turns out it does not matter at all what the magnification was ... blur is
simply a factor of exposure time (sure motion angle also enters into it but
that is a longer story) and subject velocity.
.... what do you think?
andy, andpph@rit.edu
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Note 30.7 -< Filter to make color scene look as B&W sees it! >-
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>There is a filter used to show the contrast or lack of same in a scene and to
>give the viewer a look in almost black and white tones to see if the potential
>photo would give a reasonable bxw pix. What is the number of this filter?
FYI, the viewing filter is the Wratten # 90 Monochromatic Viewing Filter.
The Wratten catalog (1945) description follows:
"This filter, No. 90, of a pure yellow color, transmits a narrow region of the
spectrum. Although it is possible to distinquish between a red and a green
viewed through this filter, the difference between colors is so dulled that
they no longer materially affect judgement as to their relative luminosity. It
is of course, impossible to construct a filter which will remove all appearance
of color from a subject, and at the same time strictly retain relative
luminosities. The filter we have produced is, we believe, the best compromise
which can be obtained; it will enable all workers who are in the habit of using
orthochromatic methods for the reproduction of colored objects to anticipate
the effect upon the photographic material before exposure. This knowledge will
also show when it may be necessary, as it sometimes is in special cases, to
modify a strictly orthochromatic reproduction by allowing play to the effects
of color contrast by the use of suitable filters."
In other words, it suggests where tones are likely to merge, which is useful
information since colors may appear quite different, though the tone reproduced
on film might be the same. Gels may be acquired at dealers and mounted in the
aspect ratio of the format between plastic sheets to prevent damage.
The total transmission is 12% (8X) which gives it a very deep yellow/brown/
sepia look. An insignificant amount of blue and green light to 550 nm are
transmitted (a "peak" of 1% at 340 nm); at 575 transmission rises to 35%,
drops to < 1% at 650 cutting red, and rises in the near IR.
From: bg174@FreeNet.Carleton.CA (Michael Gudzinowicz)
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Note 30.8 -< Polarizers for Infrared Photography - Q&A >-
--------------------------------------------------------------------------------
>A while ago, I read in an older German book [printed in 1979] that a normal
>polarizing filter has no effect on IR-film (black&white), since true
>IR-waves are not affected by the common polarizers; apparently it looses
>its polaring-effect in the longer wavelengths. The book suggested to use
>IR-polarizing-filters....
What is actually the case is that the material used in "regular", light,
polarizers transmits IR so obviously these will not polarize IR.
>I spoke to a specialist from B+W filters; filters like these are no longer
>in production, the only current type that polarizes IR works only between
>1000 and 1200nm, and are 100% black to the naked eye. Estimate price for
>this filter in the size 100x100mm is above 700 US$....;-( Does anyone know
more about this kind of polarizing filters? Brand, type, sizes, and price?
Polaroid does in fact sell Polarizing material that is effective in the near
IR. Still not cheap but available. You can order direct from Polaroid by
calling 1-800-225-2770 and they also will send out product spec sheets on
request. I was able to find out that material which works between .8 and 2.2
microns is called HR4 and the product number for a 2x2 inch piece is 605211 and
cost is $ 116 each, for a 3" square the number is 605212 and price is $182 ...
they also have larger sizes and may have near-ir polarizing filters as well.
^^^
andy, andpph@rit.edu
............................................................................
Here is a summary of the information about IR-polarizers that I found
up til now:
Besides B+W, the Goettinger Farbfilter GmbH also produces IR-polarizers, but,
like B+W, only above 800nm (same type I guess as the polarizer Andrew
Davidhazy mentioned). Price?, oh well....10 to 20 DM....but not per filter,
_per cm2!_ ....for 10x10cm that would be ehh....up to 1500 US$....
But I also spoke to Ian Gobey from the Polaroid Filters (European) headquarter
in the UK. At first he told me that they had only one IR-polarizing filter,
for use between 800 and 2000nm. But after mentioning the 'HN 7'-type, he could
remember that there was a type not listed in the regular productcharts. He
contacted Polaroid USA, and confirmed that this HN-7 type (working between 700
and 900nm) was still available, but on special request order only. It was
definately not on stock, not in the US nor in Europe. Delivery could take 4 to
6 weeks. Estimate price was 70US$ for a sheet of 12"x12", 0.015 thick
(propably mm, but I am not sure about this).
Found not only the right filter, but for a very reasonable price also!....:-))
The only thing that puzzles me right now, is, whether typical 'broadband'
IR-polarizers also exist. Since the Ektachrome, used with a orange filter, is
sensitive to the range between 500 and 900nm, the Polaroid HN 7 filter would
have no effect on the visible range. Perfect solution would be a IR-polarizer
that has a continuous working range between 500 and 900nm....
Any ideas, beside the obvious stacking of a normal *and* a IR-polarizer?
BTW, I also discovered an interesting feature of normal polarizers. When
cross-polarizing two normal (linear?) polaroid filters, the dark setting has
no effect on IR-waves, thereby making it a perfect black IR filter! (my German
book says it equals a 87 filter!). I am curious what kind of effect this will
have on the Ektachrome, since no visible color filtering takes place....the
colors don't change as with the recommended orangefilter....and the filtering
is continuous, from 0% to 100% black, so in-between-effects are also
possible....curious! I smells lots of experiments....;-))
From: MARKERINK
Subject: IR-polarizer!
==============================================================================
Note: 30.9 -< What makes a macro photograph? >-
------------------------------------------------------------------------------
>>Subject: Is close focus = macro? If not, could some one tell me what is the
>>difference.
>Close focusing doesn't necessary mean macro. When using the same lens say
>50mm. you will get higher magnification as you get closer to the subject.
>You can get closer by several method(the easiest is the closeup attachments).
>As you use stronger attachments, you get closer and the image gets larger.
>The other and better way to get higher magnification is to use a telephoto
>lens say 200-300mm. By this way, you get much higher magnification without
>the need to get closer to the subject. This is spicially true for
>photographing living beings such as butterflies that get scared and fly away
>if you get very close to them.
Macro or photomacrography generally simply refers to the magnifcation of the
image of the subject at the film regardless of what focal length or film format
you are using. The "macro" range is usually described as images whose
magnification is something between 1:10 life size and 20 times life size but the
"limits" if you want to call them that are quite flexible. Another way to think
about this range is that as long as you are using a "standard" lens you are not
in the "macro" range (unless the lens gets you to 1:1 or life size or so) and
if you have to use a microscope in front of your camera then you are in the
photomicrograph range and again not "macro". Anything in between is macro!
A second point referring to the above post is that while it is true that for a
given object distance a longer focal length lens will produce a bigger image
size most telephoto lenses do not allow you to focus as close as a shorter lens
does so you may not get the close-up magnification that you get with a shorter
lens. For nature photography (and in fact most other applications as well) it
is good advice to use the nongets focal length possible to achieve a given
magnification because this means a longer working distance and less likelihood
of the camera or lens interfering with the photography.
andy, andpph@rit.edu
.............................................................................
>>For nature photography (and in fact most other applications as well) it
>>is good advice to use the longest focal length possible to achieve a given
>>magnification because this means a longer working distance and less chance
>>of the camera or lens interfering with the photography.
>i am curious about this last advice, as I don't have much experience with
>macro work. I would tend to think that at close-up focusing, depth of
>field is so shallow that one might want to use the shortest focal length
>that gives a comfortable working distance from the subject, (which will
>vary with subject, eg flower/butterfly/grizzly bear nostril), or a focal
>length that gives the desired perspective.
In macro situations the one-sided depth of field is given by Ne c / M^2, where
Ne is the effective f-stop (corrected for bellows factor), c is the diameter of
the largest acceptable circle of confusion, and M is the magnification. Note
that f, the focal length does not appear. Thus the DOF does not depend on
focal length. (In case you are wondering if it is lurking in Ne, no, as Ne = N
(1+M), where N is the "marked" f-stop.)
(Note the qualifier above. DOF does depend on focal length when the subject
distance gets close to the hyperfocal distance. See the Lens Tutorial - (also
available for ritphoto@rit.edu with Subj: faq-lenses$txt)
From: jacobson@cello.hpl.hp.com (David Jacobson)
...............................................................................
There's a crucial issue being left out of this discussion. A lens by one
of the reputable mfrs sold as a micro or macro lens will not only focus
close, but IS DESIGNED OPTICALLY TO DO A GOOD JOB AT CLOSE DISTANCES.
Optimum lens design for shooting in the 1:2 or 1:1 range, not to mention
closer, is quite different from optimum lens design for "normal" (10 ft to
infinity) design. Ironically, some of the "micro" lenses---I'm familiar
with the Nikon line, as it happens, do very well at infinity; but the same
certainly can't be said of (say) their 50mm f 1.4 when bellowed out or
extension ringed out to do an ultracloseup. Volumes have been written
about this, but the routine amateur needs to know that for close up work
(a) just racking out the "normal" lens further WON'T get a very sharp
picture, and (b) the so-called macro setting on a lot of the newer Zoom
lenses, while a convenience, again, won't produce work of the quality of a
purpose-designed macro lens.
congreve@aol.com
==========================================================================
Note 30.10 -< Making B&W slides from B&W negatives >-
--------------------------------------------------------------------------
How to make b/w slides from negatives.
Some time ago, I enquired about methods to obtain black and white slides from
black and white negatives. I received many answers, and in particular I had
long email discussions with Ron Speirs. He taugth me a very simple and
effective procedure, that I followed with very rewarding results. In this post
I will present that procedure, together with some additional suggestions.
Let me remark that black and white slides can be truly beautiful. Their tonal
range greatly exceeds that of b/w prints, and often exceeds that of color
slides. You can see the most brilliant highlights side to side to detail in the
deepest shadows, without sacrificing the overall contrast.
Also, making b/w slides from negatives takes far less time than making final
prints. I once used to spend hours printing, and there were still many, many
negatives that I would have liked to see, but had no time to print. Now I can
quickly make slides from all the interesting negatives, and I can print only
the ones that I feel deserve it. I can do my snapshooting in b/w now!
The method.
The method is rather simple. With a slide duplicator, shoot duplicates of the
negatives on Kodak 5302 Fine Grain Positive Release Film, then develop in Kodak
D-11.
The film.
Kodak 5302 film is sold in 100 ft rolls, so that you need a bulk loader to load
it in film cassettes. It is very inexpensive: a 100 ft roll is about $12. Other
films that can be developed to a moderately high contrast would do as well: for
example, Technical Pan. I stick to 5302 because it is so inexpensive, it
tolerates process variations fairly well, and because I don't want to begin
again testing exposure and development times for a different film.
The duplicator.
I use a Rokunar 1:1 non-zoom slide duplicator. It is a fixed f/8 duplicator,
and the quality is good enough for my taste. This means that the weakest link
of the chain is the quality of my projecting lens, and not the quality of the
slide duplicator. The duplicator requires a T-mount, that is rather
inexpensive. Mail order, one can get the duplicator and the T-mount for $65 +
shipping.
The type of the duplicator is important. The duplicators are normally designed
for slides, not for negative strips. The above 1:1 duplicator can be used with
negative strips; but I don't know whether the same applies to other brands or
to zoom duplicators.
With the above duplicator, all you need to do is to get one of those glassless
slide mounts with hinged cover, such that the hinge runs parallel to the long
side of the slide. Then, file the mount so that you can slip in it a whole
negative strip without the mount scratching it. The mount should still be able
to grip the film strip so that it won't move. Once this is done, it is very
simple to position the slide mount on the negative strip and copy one frame at
a time.
Exposing the film.
Kodak 5302 is not very light-sensitive: depending on the blue content of the
light, it is between 1.2 ASA and 0.3 ASA. In fact, the film is blue sensitive,
and can be handled under a red safelight (see the instructions packaged with
the film).
I have found that the best way of exposing it consists in shining the light
from a slide projector on the white piece of diffusing plastic of the
duplicator. This is the most intense light source that I have available in my
darkroom. I keep the duplicator about 15 cm from the projector lens. One must
be careful that the light from the projector illuminates uniformly the piece of
white diffusing plastic.
I set the ASA dial of my camera to 50 ASA, and when I read an exposure time
between 1/15 and 1/8, I set the shutter speed to 2 seconds. This is a starting
point (but works fairly well). As usual, you can change this to obtain
particular effects: longer time for a darker slide, shorter for a lighter
slide. The film does not seem to suffer much from reciprocity failure for these
times. I did not find mirror lock-up to have much effect on the sharpness of
the duplicate.
Processing the film.
I develop Kodak 5302 in working-strength D-11, for about 6 minutes at 20 C,
with 2 inversions every 30 seconds. Then, I follow the usual processing steps:
stop bath, fix (I use two baths of Ilford rapid fixer for two minutes each),
rinse, hypo clear, final wash. By varying the development time, it is possible
to control somewhat the slide contrast.
I found that Dektol and HC-110 do not provide enough contrast for my negatives:
the slides have a grayish look, and the maximum density is not high enough.
Dektol can be a useful developer for negatives that have a higher contrast than
mines, though.
Luca de Alfaro (luca@cs.stanford.edu) (opinions stated here belong to me, and
do not necessarily reflect those of my employer).
==========================================================================
Note 30.11 -< Photo Attractions in Boston, Chicago, Las Vegas & Mobile >-
--------------------------------------------------------------------------
BOSTON .....................................................................
> Later this month I will be going to Boston and Northern New England for the
> first time. I'm from Arizona and this part of the country will be new and
> different for me. I could use some suggestions on what to see and photograph
> to get a feeling for the culture and environment of the area.
I live outside of Boston and have never been to Arizona, and have only seen
photos. Depending on what you are interested in, NE has a very wide variety of
scenery. Boston itself is very attractive, with buildings dating back over 200
years, so the architecture would probably be very different from what you are
used to. Cape Cod National Seashore is one of my favorite places. There are
sand dunes, but probably very different from what you are used to seeing in the
SouthWest. For Historical Interest, Plimouth Plantations and Old Sturbridge
Village are interesting for their perspective on life in Colonial America, and
the architecture and town layout. North of Boston are the towns of Gloucester,
Rockport, Magnolia, and Manchester. These offer very different scenery, as the
coast there is very rocky (Rockport is very appropriately named) which is quite
different from the Cape Cod coast line 2 hours away. These towns are on Cape
Ann ("The Other Cape"). Rockport has a red fishing shack on a pier jutting out
into the harbor, which has the reputation of being one of the most photographed
and painted buildings, at least in New England. It is usually referred to as
"Motif No 1".
Further north into Maine the coastline is also very rocky, with long rocky
inlets from the ocean. The mountains in New Hampshire are much older than the
Rockies, so they are considerably more worn down, and not as striking, but
beautiful in their own right.
There are towns throughout the area, which may not necessarily have anything
particularly distinctive, aside from having town centers which have not changed
much in 200 years. For some of them, perhaps spring, when all the flowers are
in bloom, and fall, when the leaves are turning, are the prettiest times to see
them, but they might be worth a visit depending on your time frame.
From: Bill Leigh, wleigh@xionics.com
CHICAGO ........................................................................
> I will be travelling to Chicago. I will only be there for three days but I
> hope to do some sight-seeing and hopefully get some shooting in. I will be
> quite limited to the downtown area and would appreciate it if anyone has any
> suggestions of good places to visit (and any areas I should avoid)
Chicago is a nice place to visit, and you know the rest. It is full of
interesting things to photograph. I particularly like Michigan Ave. w/ the
colorful people and street musicians. Perhaps for a donation, they will let you
photogaph them. The tall buildings are awesome, as is the view from the John
Hancock and Sears Towers which you can get about a fifty mile view on a clear
day. Night is also spectatular. I like photographing the skyline and it's
reflection in Lake Michigan from the Adler Planetarium. It 's a small peninsula
that juts out in the lake. It makes a great view just after sunset. Be sure to
pick up a map of downtown. The Chicago River has many drawbridges with various
vessels afloat. Also, Chicago is known for it's modern architecture. As a
country boy, I am facinated by the lights, glamour and excitment of Michigan
Ave. On my first visit, I sunburned the roof of my mouth. Check out the great
museums, The Art Institute, Museum of Science and Industry, and the Field
Museum of Natural History. An awful lot for three days. Have Fun.
Always the Art Institute and the Museum of Contemporary Photo south on Michigan
From: Kim Mosley
MOBILE (Alabama) ..............................................................
In addition to the USS Alabama, in downtown Mobile you have historic Fort Conde
which is a partial restoration of the orginal city hundreds of years ago. There
is also Fort Gaines located on Dauphin Island about 25 miles south of the city.
Fort Morgan is located opposite Gulf Shores in the next county. Both Forts
Morgan and Gaines protected the mouth of the Bay from invasion during the Civil
War. Very little has been done to Fort Morgan. It is pretty much in ruins as I
recall, but picturesque. Fort Gaines has been restored and is a thriving
tourist attraction. There is a Ferry that links both Dauphin Island and Fort
Morgan. The trip last about 30 minutes. The alternative is about a 1 1/2 hour
drive by car. Since I am here, will be glad to answer any additional questions
you or anyone else may have.
From: maf00217@ns1.maf.mobile.al.us ("Robert A Vogtner")
more:
The boat's there, but if I may jump in with an alternative suggestion: don't
miss the gardens if you're in the area -- Bellingrath (spelling?) Gradens are
world class. They are grand southern gardens -- plantation style opulence. If
you have to choose, forget the boat.
From: Joe Angert, St. Louis Community College, <0007372155@mcimail.com>
LAS VEGAS......................................................................
> Will be heading to Las Vegas in August. Can anyone tell me some good sites to
> photograph (Outside of Vegas)? Will have a rental car so that will not be a
> problem. Let say about a fifty to hundred mile range of Las Vegas.
You may want to consider visiting Hoover Dam and Lake Mead south of Las Vegas.
Raft trips down the Colorado River below the dam are available (much more
sedate than the ones through the Grand Canyon!).
Local Las Vegas attractions (*besides* casinos) include Red Rock Canyon
Conservation Area about 45 minutes west of town along the Spring Mountains, Mt.
Charleston (also in the Spring Mt. range) (ele. ~12,000 feet) northwest of town
about an hour and Valley of Fire State Park northeast of Las Vegas about an
hour by freeway. Two photo-l members who have visited Las Vegas have really
enjoyed their trip out to this park, noted for its firey red rock formations.
From: jonker@hgl.signaal.nl (Erik Jonker)
Yes try "Valley of Fire" state park N.E. of Las Veges, great for late afternoon
shots with sun low in the sky.
From: ImagesInt@aol.com
Hoover Dam would be a start... :-) Near Boulder City. I'd take a helo ride
from SunDance Helicopters - get the LEFT side in the passenger area and shoot
through the sliding vent.
Red Rock - you will need to find out sundown time and get there about an hour
before - the place really mellows as the sun drops in the sky. Good cacti
against a red background!
From: r-roper@uiuc.edu (Roy Roper)
Be prepared for the heat (100-120) when you come out in august.. :) after
living here almost 6 yrs im still not used to it. PS: if you're tight on time
(can't go to red rock and valley of fire) i would say skip red rock and head
out to valley of fire its much nicer IMHO. sunsets/rises at valley of fire are
beautiful, at red rock you have to wait for the sunsets.
From: Casey Lewis, lewis@nevada.edu, University of Nevada, Las Vegas
The Mormon Temple in Las Vegas is really cool at night...
From: Brett Pfingston (bpfingst@indiana.edu)
==========================================================================
Note 30.12 -< Favorite Textbooks of PhotoForum readers >-
--------------------------------------------------------------------------
The Focal Encyclopedia of Photography by Stroebel & Zakia - Focal Press
should be a required reference and considered for the upcoming gift-giving
season. :)
From: eugene@sequoia.lle.rochester.edu (Eugene Kowaluk)
Photography From Theory to Practice from Star Publishing is a good basic text.
From: "Leary, Mike"
Photography and the Art of Seeing - Freeman Patterson
Photography of Natural Things - Freeman Patterson
Both are excellent books. The first is my favorite. FP also now has a book out
which is a "workshop in a book" book. Have not seen it yet but it's on order.
From: RMACEACHERN@HUSKY1.STMARYS.CA
One of the books that I rely upon constantly is:
_Photographic Facts and Formulas_ by E.J. Wall and F.I. Jordan. (a more recent
version, was edited by J.S.Carroll and appeared from Focal Press in 1975.)
This is more of a reference book, I guess, but it is so full of information I
just don't understand why anyone would try to get by without it.
From: Larry Bullis
I have found the following to be of interest:
1. The Burden of Representation - John Tagg 1988
2. 13 Essays on Photography- Canadian museum of Contempory Photography 1990.
3. Classic Essays on Photography - ed. Allen Trachtenberg 1990.
4. Photogenic Papers - ed. John Richardson (Continuum - The Australian
Journal of Media and Culture, Vol 6, No 2 1993)
5. The Critical Image: Essays on Contempory Photography - ed. Carol
Squires, Bay Press Seattle 1990.
6. Disrupted Borders: An Intervention in Definitions of Boundaries - ed.
Sunil Gupta,Rivers Oram Press / London1993
From: mclennan@giaeb.cc.monash.edu.au (Brett McLennan)
The book " Photographers On Photography" edited by Nathan Lyons is an
excellent collection of essays by photographers. Unfortunately it is out of
print also. I have found "Seeing with the Mind's Eye" by Samuels & Samuels to
be a good book to get students thinking creatively.
From: Russell J Rosener
I have twice used as a text Mark Jacobs and Ken Kokrda's *Photography in
Focus*. In many ways it is an ordinary textbook, but it does contain some
rather well-presented chapters on photograms, pinhole cameras, "visual aspects
of photography," special processes and techniques, and the history of
photography. It was the chapter on the history of photography that initially
attracted me to the book: although it's short, it does give the students some
readymade "notes" which I am able to amplify with lectures and slides.
I also recommend that students have a look at Terry Barrett's *Criticizing
Photographs: An Introduction to Understanding Images*. Barrett presents a good
*introduction* to art criticism and to aesthetic theory, and does an especially
nice job regarding describing, interpreting, and evaluating photographs. These
last three sections are very helpful when we begin critiques.
From: "David L. Rayfield"
There are a couple of books which are my favorites, (though I have a vested
interest-I have workbooks available for each.) One is Henry Horenstein's
classic, Black and White Photography and the other is David Curl's
Photocommunication. If you are a teacher, please email me if you would like
sample copies of either (and/or the workbooks which accompany them.)
From: Kim Mosley
"vintage and classics"
Handbook of Photography by Henney and Dudley - Whitlesey House
Ilford Manual of Photography - Ilford
Applied Photography by Arnold, Rolls and Stuart - Focal Press
The Photographic Process by Mack and Martin
Principles of Photographic Reproduction by Miller - MacMillan
Fundamentals of Photography by Neblette - D. Van Nostrand
Fundamentals of Photography by Boucher - Morgan and Morgan
View Camera Technique by Stroebel - Focal Press
In-Water Photography by Mertens - Wiley Interscience
and books by Langford (Focal Press) and Blaker (Freeman)
I also can't resist picking up any book by Andreas Feininger
but they all tend to look alike after a while! :-)
From: andpph@rit.edu (Andrew Davidhazy)
Amateur Photographer's Handbook by Aaron Sussman. I have noticed how quickly
I whip out my cash whenever I find a used copy this book. I always know some
student who needs a book that has a lot to say about the basics. I like to
have a few on hand to give away.
From: Larry Bullis
==========================================================================
Note 30.13 -< The Argyrotype Process >-
--------------------------------------------------------------------------
ARGYROTYPE
Mike Ware
(version of 12 August 1994)
A new 'user-friendly' iron-based silver printing process, related to the
Kallitype, Argentotype, Sepia, Brownprint and Van Dyke processes of the
19th Century, but offering some advantages over them in the economy of
materials and effort, and in the quality and permanence of the image.
Sensitizer Chemicals needed:
Sulphamic acid 7 g (spelt 'sulfamic' in the USA)
Silver(I) Oxide 7 g
Ammonium Iron(III) Citrate (green crystals) 22 g
Tween 20 (wetting agent) about 0.2 cc
Distilled water to make 100 cc
Making up Sensitizer (under tungsten light)
1) Heat about 70 cc of distilled water to 50-60 C, and dissolve 7 g of
Sulphamic Acid in it.
2) Add 7 g of powdered Silver(I) Oxide to the hot solution 1) in small
amounts with vigorous stirring until all is dissolved.
3) Add 22 g of Ammonium Iron(III) Citrate (the green variety) to the warm
solution in portions, with stirring, until it is all dissolved. Allow to
cool.
4) Add 0.2 cc of Tween 20 and mix well.
N.B.The appropriate quantity of this wetting agent is variable and will
depend on the paper used.
5) Add distilled water (at room temperature) to make a final volume of 100
cc and filter the solution to remove any small amount of solid remaining.
(The solution should be a clear deep olive-green colour.)
6) Store in a brown bottle in the dark at room temperature.
(The solution should keep for a year, at least. If it throws down a small
amount of black precipitate, it should be re-filtered.)
7) To make a more contrasty sensitizer, dissolve an extra 1 g of sulphamic
acid in 100 cc of sensitizer.
CAUTION The solution is toxic and will stain skin and fabrics: wash away
spillages with plenty of cold water.
Papers
The purity of the paper is critical: of the UK papers tested so far,
Whatman Watercolour, Saunders Somerset and Atlantis Silversafe Photostore
are recommended, but the best is Ruscombe Mill's handmade Buxton paper. The
wetting agent, Tween 20, is included in the sensitizer formulation to
assist uptake of the sensitizer by the cellulose fibres, which minimises
"bleeding" of the colloidal metal image during processing, but it may cause
uneven penetration of some papers that contain a mixture of fibres.
Discovering the best paper is a matter for personal experiment.
Coating
A 10"x8" coat requires about 1.6 cc, depending on the paper, if a glass rod
spreader is used. Brush coating will consume more.
Allow a few minutes for the sensitizer to soak in, until the paper surface
appears non-reflective, then dry for about 10 minutes in a stream of warm
(40 C) air. Alternatively, simply allow to dry at room temperature and
humidity for about an hour. The sensitized paper should be used within a
few hours, unless a desiccated box is used for longer term storage: 'shelf
life' in a dry environment is at least a week.
Printing
As with platinum-palladium printing, a negative with a long density range
(0.2 to 2, or so) is desirable, obtained by "overdeveloping" by 70%-80%.
Softer negatives may be accommodated by using the more contrasty sensitizer
recipe. [Indeed, by mixing the two formulations, the contrast of the
sensitizer could be 'fine-tuned'.]
Printing is by contact, using a UVA source or the sun. Exposure is similar
to other iron-based processes, e.g. platinum/palladium.
If the relative humidity of the paper is 'normal' (ambient RH between 40
and 80%), a detailed print-out image will be obtained, orange-brown on a
yellow background, which gives a good indication of correct exposure,
making test strips unnecessary. A little development (half to one stop) can
subsequently be expected to occur in the high values during wet processing,
and there will be considerable 'dry-down' of the tonality: both factors
should be taken into account in judging exposure; the colour will also
darken to a rich brown in the fixer bath. It is better to overexpose than
underexpose, because a dense image can be 'reduced'.
Colour
The colour of the print-out image may be shifted to a more neutral tone if
the sensitized paper is humidified before exposure by leaving it above
water (100% RH) for 30 minutes at room temperature. This is a very
economical method of colour control!
CAUTION: Humidified sensitized paper can damage negatives during contact
printing unless a protective layer of very thin polyester film is
interposed between the two.
Wet Processing
This is extremely simple and non-critical, requiring only one inexpensive
solution, 2% Sodium Thiosulphate: dissolve about 20 g of the crystals in 1
litre of water. This bath has a capacity of about ten 10"x8" prints and
should be replaced when necessary.
1) Develop and clear in running water at room temperature for 5 mins.
2) Immerse in the 2% Sodium Thiosulphate clearing bath for about 3 mins.
3) Wash the print in water for 20 mins and air dry at room temperature.
NOTES:-
1) The yellow unexposed sensitizer should disappear completely within
this time. If there is any "bleeding" of colloidal silver metal, indicated
by a red-brown stain running off the image and loss of image density, then
this problem results from the paper fibres failing to trap the tiny silver
particles; it is especially likely if insufficient Tween is used. The
effects of "bleeding" may be minimised by processing the print face down,
to avoid staining adjacent areas. If a particularly long tonal range is
desired with very delicate high value gradations, the exposed print should
be left in a humid atmosphere (100% RH) for ten minutes before wet
processing; several steps of highlight detail will build up.
2) The image should intensify in the fixer, improving the shadow
gradation, and the colour will rapidly transform from red to brown. (As the
bath 'ages' its action in this respect increases). Overlong treatment in
this bath and exposure to air will result in loss of image density
especially in the highlights; it may be used to 'reduce' an overexposed
print, or a standard, non-acid fixer may be used. If, on the other hand,
very delicate highlight detail is desired, a little ammonia may be added to
the clearing bath to make it distinctly alkaline (pH 9 to 10); this
inhibits the dissolution of silver, but may raise the level of residual
iron in the image.
3) The image 'dries down' significantly - at least one Zone. Heat
drying on a ferrotype plate or by ironing, may shift the colour to a more
neutral blackish brown.
Permanence
Like any colloidal silver image, an Argyrotype is inevitably rather
susceptible to attack, especially by acids and sulphur-containing
substances. However the residual iron and silver in the unexposed areas
should be very low and image stability and lightfastness are good.
If improved permanence is desired, then try selenium toning (Kodak selenium
toner, diluted 50 to 100 times for a minute or so). Toning with gold,
platinum or palladium should also be possible, and the image should also
respond readily to sulphide toners, but I have not yet tested all these
options.
Disclaimer
This information may be copied and circulated freely (preferably with
acknowledgement!), but the author cannot accept liability for any injury,
damage or loss resulting from its use.
Reference
'The Argyrotype Process' by Mike Ware, British Journal of Photography,
No.6824, 13 June 1991, pp. 17-19.
From: Mike Ware
=========================== end of section 30 ==========================
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