6.13 How can I process reversal films at home? (Film Laboratories)
Description
This article is from the rec.arts.movies.tech FAQ, by Scott E. Norwood snorwood@nyx.nyx.net with numerous contributions by others.
6.13 How can I process reversal films at home? (Film Laboratories)
(courtesy Ed Inman edinman@teclink.net)
From: edinman <edinman@teclink.net>
Newsgroups: rec.arts.movies.tech
Subject: (no subject)
Date: 7 Jun 1996 01:50:18 GMT
Here is my advice on how to reverse process your Super 8 or 16mm black
and white movies at home. Why would you want to do this? There are
several reasons. For example, the film may be of a personal or sensitive
nature that you would feel uncomfortable sending out to a lab. But the
best reason to home process your film is that you get to see it right
away, instead of sending it off and waiting.
There is not much that has been written on this subject in years, so the
following suggestions are based only on my personal experimentation. If
anyone who has experience with this sort of thing would care to make
suggestions on how I could improve or refine this process, or would like
to ask any questions, feel free to e-mail me.
HOME B&W MOVIE/SLIDE PROCESSING:
The only home movie processing tank still sold that I am aware of is the
G-3 Daylight Processor sold by Doran Enterprises in Milwaukee,
Wisconsin, USA. Their phone number, if you wish to order one is
414-645-0109.
The tank is not ideal--the good news is that it only takes one liter (or
one quart) to process up to 200 ft. of Super 8 or 16mm film (or about
1.5 liters for 35mm film). The bad news is that it is kind of tedious to
use.
Since it is a "rewind" tank, the operator must continuously wind the
film back and forth from one reel to another. At recommended winding
speed of 2 turns per second, a complete wind of one 50-ft. Super 8 film
would be about 45 seconds from one end to another. For 100-ft spool of
16mm (or two Super 8 films stapled together) the time would be one
minute. At 200 ft., time would be 90 seconds.
IMPORTANT:
1. Emulsion should be face out.
2. Unless Prebath PB-3 is used when film is first submerged, tilt the
tank and pour in enough water so that the reel with no film is wet and
reel with film is dry. Then wind dry film onto wet reel so that emulsion
is uniformly made wet.
PROCESSING STEPS:
I do not have recommendations for developing Ektachrome film but for
developing B&W films like Tri-X Reversal 7278 or Plus-X Reversal 7276,
use the following processing steps:
SOLUTION and suggested NUMBER OF WINDS AT 68F (20C):
FIRST DEVELOPER: 12 (Or 8 at 80F--This is the most critical step.
Decrease number if fully processed films are consistently too light;
increase if too dark.)
RINSE: 4 (change water each time)
BLEACH: 10 (8 at 80F)
CLEARING BATH: 8 (6 at 80F)
Now remove cover of tank, add water, and re-expose film under a bright
200 to 500 watt light or in sunlight for two to three complete winds.
Cover tank and continue:
SECOND DEVELOPER: 8 (6 at 80F)
You may now rinse film (5 winds running water) and dry, OR if you want
to harden emulsion and make film less prone to scratches (recommended if
the film is expectd to have heavy usage) add the following steps:
RAPID FIXER: 2
RINSE: 2
HYPO CLEARING AGENT: 2
RINSE: 5 (running water)
PHOTO-FLO (optional):2
To dry film, string a line across the room and loop film over and over
the line, emulsion side up, for uniform drying. Spool onto projector
reel emulsion side out.
SUGGESTED SOLUTION FORMULAS:
FIRST DEVELOPER: Add 9.5 grams of sodium thiosulfate to 1 liter of Kodak
D-19 developer regular strength.
BLEACH: To one liter of water add 9.5 grams of Potassium Dichromate and
12 ml of concentrated Sulfuric Acid.
CLEARING BATH: To one liter of water add 90 grams of Sodium Sulfite.
SECOND DEVELOPER: Use standard paper developer like Dektol or Polymax T
regular strength.
FIXER: Use Kodak Rapid Fixer or similar.
HYPO CLEARING AGENT: Use Kodak Hypo Clearing Agent, or similar.
PHOTO-FLO: Use Kodak Photo-Flo or similar.
These solutions can also be used to make B&W slides from almost any 35mm
B&W film. The recommended starting point times for a standard
(non-rewind) tank at 20C (68F) is:
FIRST DEVELOPER: 6 min.
RINSE: 2-5 min. (change water frequently)
BLEACH: 1-2 min.
CLEARING BATH: 2 min.
RINSE/RE-EXPOSE (You can't overexpose at this point)
SECOND DEVELOPER: 5 min.
RINSE/FIX/DRY normally.
As a general rule, just remember:
If too dark, increase time or temp. of first developer.
If too light, decrease time or temp. of first developer.
TO ORDER HARD-TO-FIND CHEMICALS call Photographer's Formulary toll free
at 1-800-922-5255. (Note: They only sell sulfuric acid in a 48 percent
solution so you will need to use 25ml for a liter of bleach instead of
the 12ml you would use of concentrated solution.) If you want to get
really fancy, try some of their many toners, intensifiers, or reducers
on your films or transparencies--experiment first with unwanted films
since you don't want to risk ruining your good films.
DISCLAIMER: Potassium Dichromate and Sulfuric Acid are hazardous
chemicals which should be treated with extreme care and handled as
hazardous waste. If in question, the bleach formula should be made by a
qualified chemist. Also, bleach does not keep as well as the other
solutions when mixed. For best keeping, you may want to add the
potassium dichromate to one-half liter of water to make BLEACH PART A
and the sulfuric to a separate half-liter of water to make BLEACH PART
B. The two then are mixed together in equal amounts just prior to usage.
Additional Tips:
1. By adding an optional rinse between the bleach and the clearing bath,
you can probably extend the useful life of the clearing bath. But for
most consistent results always use fresh chemistry.
2. If highlights appear to be not fully reversed (I.E. gray image where
there should be white) the bleach is exhausted or you need to increase
bleach time.
3. If yellow stain appears anywhere in film, clearing bath is exhausted
or you need to extend clearing bath time.
4. If fixer erases part of the final image, you did not fully re-expose
or redevelop the film or your redeveloper is exhausted.
5. To use the G-3 tank for negative processing, use regular D-19, then
fix, wash and dry normally.
6. For high contrast applications (such as titles or line work) use
Kodalith developer in both the first and second development stages, or
as a negative developer.
Best of luck--let me know how you come out.
Ed Inman -- E-mail -- edinman@teclink.net
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