Graphic Techniques for Biological Presentation

Black-and-White Halftone Copy Work

Setting up for copy work:

use the same copy stand unless if you want to recalibrate your exposures everytime that you work.
arrange illumination at 45 degrees to the copy. Proper photolights are expensive, burn hot, and age fast. Leave the lights on only during camera use. (Keep in mind that turning the lights on and off for each exposure also will age the bulb--organize your exposures.)
copy work should be clean, masked when needed to suppress extraneous information.
for 4 X 5 copy negatives: load film holders with 4 x 5 film in total darkness for panchromatic film. Notches on one corner of the film should be up and to the right to insure that emulsion is face up. Place film slide with the silver surface face up.
for 35 mm copy negatives: load 35 mm camera with a suitable film like Technical Pan 2415 at ASA 125. Develop in D-76 according to manufacturers instructions for contrast index of 1.0.

Determining exposure:

check exposure with a gray card at the appropriate ASA of the film.
expose test film (push film slide 1/4 of the way inward) at 1/30, 1/15, 1/8, 1/4 second at f/11, based on four 150 watt photolights.
develop, rinse, fix, and wash. Examine negative to determine best exposure. -calculate exposures on test strip by adding the exposure times. Do this carefully. Use longer or shorter exposures depending on the specific copy stand you use.
exposure should only vary with intensity of the lamps and image.
recalibration should be needed only when the lights are replaced with brighter or dimmer bulbs, or when the camera distance to the copy work becomes significantly different (inverse square law applies).

Photographing the Copy Work:

flatten copy by securing it will tape, if the copy curls excessively, or as a last resort, under glass.
if glass is used, it must be scrupulously clean. Watch closely as presstype or transfer letters may be transferred to the glass.
center copy and remove extraneous detail from field of view.
open shutter and focus copy camera at wide open (f/3.5 or largest aperture) on ground glass in the viewfinder.
reset aperture to f/11 (or desired f-stop), close shutter, insert film, pull film slide, and expose.
develop, stop, fix, and wash according to film recommendations.
record your settings for future use!
develop your film as you go. Bracket exposures only when your exposure does not work.

Film: T-Max 100 Panchromatic 4 x 5 sheet film, ASA 100
Development: 5 min HC-110 dilution B.

Black-and-White Halftone Transparencies

From negatives of any size:

construct cardboard mask same size as negative
use evenly illuminated light box
image of the negative is then recorded using a SLR 35 mm camera
image composition is accomplished by magnifying or reducing the image in the viewfinder of the camera
determine contrast needed prior to exposing film(!) Read instructions with film.

Film: Technical Pan Film 2415
Exposure: determine exposure for a given gray level in illuminated negative
ASA: dependent on development
Development: adapt to contrast needs (usually moderate to high contrast is good)

Problems:

bracket exposure densities (1/2 stop steps)
dark positives are underexposed
light positives are overexposed
project negatives to judge them; use same room size for which slide is needed
avoid stray light

From 35 mm negatives:

contact print using a 4 x 5" piece of glass and an enlarger at low illumination or high f/stop to reduce light
Eastman Fine Grain Positive Release Film is placed emulsion side up on the enlarger--OC safelight is okay, same as photographic paper!
negative is aligned and placed emulsion side down on the Release Film
test strips are made as with photographic papers using different exposure times. Aim for about 10 seconds. Burning and dodging is touchy, but possible.
film is developed in either D-19, Dektol (1:2), or D-76 for high, medium, or low contrast under safelight
rinse 30 seconds, fix 4 minutes, rinse 20 minutes (final change with Photo-Flo or distilled water) and dry
bracket your exposures.
judge films by projecting them.
for line drawings, contact print with Kodalith Ortho sheet film using red safelight and Kodalith Ortho developer, parts A and B mixed 1:1.
biggest problems are scratch marks on the glass and dust printed on the slide.

From prints or plates:

Method 1. Make an internegative

see "Halftone Copy Work" and then use above method.

Method 2. Direct Positive Reversal method, using below:

Film: Panatomic-X at ASA 64 or Technical Pan 2415 at ASA 50
Procedure: Photograph original negatives as you would for copy work.

Load exposed film in processing tank, make sure the solutions below are mixed.
Develop 6 minutes at 20 C with D-19 (1:2).
Wash 30 seconds.
Bleach for 3 minutes in solution of 15 g in 750 ml of water. Add 15 ml of concentrated sulfuric acid and mix to 1000 ml. (Stock lasts for 6 weeks or six rolls.) Film may be exposed to light from this point on.
Rinse until yellow color is totally removed, even if it takes a long time. Residual bleach will remove the image with time and color the negative.
Clear film using clearing solution of 100 g anhydrous sodium sulfite in 800 ml. Mix to 1000 ml. (Stock lasts for 6 weeks or 6 rolls.)
Rinse for 1 minute.
Re-expose film to white light completely for 60 seconds until all emulsion is totally re-exposed.
Develop 2 minutes in D-19 from step 1.
Rinse 30 seconds.
Fix 5 minutes.
Rinse 20-30 minutes.
Use dilute Photo-Flo or distilled water in final rinse and dry.

Method 3: Solarization Reverse Contrast

Film: Kodak High Speed Duplicating Film 2575

set up copy stand as for copy work with four 300 watt photolights
set camera aperture at f/5.6, expose copy for a total of 22 seconds.
for the first 20-30% of the exposure (4-7 seconds) place a white card in front of copy to provide contrast control. The more white card, the lighter the resulting slide.
adjust fogging time and overall exposure to vary slide density and contrast.

Remember:

light is overexposed, dark is underexposed.
Development:

Dektol (1:2) dilution for 3-4 minutes at 22 C in the dark. Rinse, fix, wash, and dry as per instructions.

Method 4: Solarization Reverse Contrast

Film: Kodak Direct MP Film 5360 (repackaged by Ted Pella, Inc., catalog # 24611 [available in 100 ft. roll], 4595 Mountain Lakes Blvd, Redding, CA 96003-1448, orders: 1-800-237-3526)

set up copy stand as for copy work
using the departmental MP-3, f/3.5 20 seconds exposure for line copy (bracket either side using 5 sec intervals) or for continuous tone f/5.6 13 sec (bracketed at 3 to 5 seconds)
increases contrast slightly. Some line copy work is not suitable for this technique

Remember:: light is overexposed, dark is underexposed.
Development:: Dektol undiluted for 7 minutes at 21 C in the dark. Rinse until red color is totally washed out, fix 5 min, wash 20 min, and dry as per instructions.

Method 5: Solarization Reverse Contrast

Film: Kodak LPD4 Film

this film was primarily developed to produce line drawings, tables and charts. Contrast control for continuous tone copy is obtained by fogging the film with a "flash" of a white surface
exposure times will vary with each set-up and with distance from subject to the lens. Use f/8 for all exposures

Distance	Exposure
>30 cm	10 seconds
25-30 cm	11 sec
20-25 cm	12 sec
15-20 cm	13 sec

for continuous tone:: for the first 2-4 seconds of the exposure place a white card in front of copy to provide contrast control. The more white card, the lighter the resulting slide. Adjust fogging time and overall exposure to vary slide density and contrast.
for line copy:: don't fog!
Remember:: light is overexposed, dark is underexposed.
Development:: Dektol (1:1) dilution for 5 minutes at 21 C in the dark. Wash in running water for five minutes (3 to 5 changes). Fix for three minutes, wash 20 minutes, dry and mount. (Source: Wayne Elisens' reference sheet.)

Black-and-White Line Transparencies

From negatives of any size:

see B & W halftones section, for details
use evenly illuminated, masked light box, and 35 mm camera
determine light reading for appropriate ASA for gray card
bracket by 1 stop (less makes little difference)

Film:: Kodalith Ortho Film (orthochromatic)
ASA:: 25
Development:: 2-1/4 minutes at 20 C, using Kodalith Ortho developer (parts A and B mixed 1:1)

Problems:

bracket exposures (1 stop)
imperfections, dust on positive is a problem!
should project as they appear
avoid stray light

For 35 mm negatives:

contact print using Kodalith Ortho sheet film with dim light from an enlarger.
place Kodalith emulsion side up. Align negative to be printed emulsion side down and place glass on top of negatives (apply pressure to get good contact) and expose.
printing can be done under red safelight. Development is conducted using Kodalith Ortho, parts A and B mixed 1:1 in a tray.
Stop, fix, and wash as for negatives.
Biggest problems are dust and scratches. Project results to evaluate quality and most desirable line width.

Black-and-White Reverse Contrast Line Transparencies

(use this for diazos, if you must use diazos!)

use only for true blacks and true whites, using only clean copy!
using copy stand for illumination, position copy with lights at 45 degree angle, overhead lights out
glass may be used to flatten copy, but better without it
examine for needed masking
test lighting with gray card for appropriate ASA
bracket by 1 stop intervals

Film:: Kodalith Ortho Film (orthochromatic)
ASA:: 25
Development:: 2-1/4 minutes at 20 C, using Kodalith Ortho developer (parts A and B, mixed 1:1
Problems:: bracket exposures (1 stop); imperfections are holes in the negative (Kodak opaque black may be used for "pinholes"; project these to check black levels and line size

Note: Among the correct exposures, line size is the only thing that will vary. Projecting the slide is required to evaluate its suitability.
A flashy touch: Color the white lines so that the viewer's eye undergoes less stress and to attract interest. (This can however be overused.)

for whole slide color changes, use gels (approx. $1 each)
colored report covers work, but must be mounted in glass mounts to prevent warping in the heat of the projector
for line-by-line color changes, use water-soluble felt pens.
check suitability of pens on spare negatives first!!!!

Image Removal for Graphics Applications

draw object using indeliable ink onto a "discard" photograph
immerse the marked photograph into the following solution to remove the image: add 3 g iodine crystals, 50 g potassium iodide, and 10 ml glacial acetic acid to 800 ml of water. Filter before use and store in dark to prolong life. Continue to immerse until paper has turned brown.
drain the print
immerse in fixer until brown color and photographic image has disappeared. Repeat bleaching and fixation until image is removed. Fix until white background is obtained.
wash 1 hr and dry. Make a high quality xerox of your drawing, because this procedure sounds anything but archival in quality!

Colored Slides of Line Copy Work

color film such as Vericolor-X can be used to produce color negatives. The procedure is the same as photographing line drawings with other films.
background colors can be varied by varying the filter combinations used, by multiple exposures and through the use of masks.
black text on a white background is photographed with a Wratten filter superimposed on the lens.
below has some suggestions for ideas to try.

Background color	Filter type	Exposure increase (in f-stops)
Diazo blue	12 or 15 (yellow)	2
Cyan	85B or 85 (orange)	4
Green	34A (deep magenta)	4
Red	38 (light blue)	4
Orange	44 (cyan)	4
Magenta	61 (deep green)	5
Yellow-brown	47 (deep blue)	4
Dark red	no filter	0

Note: Weaker filters give softer, more natural colors and may give colored lines or text. Stronger filters give more saturated colors. Development: C-41 process. Source: Eastman Kodak publication S-30, "Slides."

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