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Subject: rec.photo.darkroom Read Me Before You Post
This article was archived around: 8 Mar 2001 03:30:05 +0100
Last-modified: 4 Jan 2001 21:41:24 GMT
Rec.Photo.Darkoom Frequently Asked Questions
Cees de Groot <mailto:firstname.lastname@example.org>
Table of Contents
1.1 I don't have access to the Web
1.3 Disclaimer, copyright
2. General information
2.1 What is rec.photo.darkroom all about?
2.2 What is The Link?
2.3 Your Mileage May Vary?
3. The darkroom
3.1 How do I build a darkroom?
3.2 Can I use tapwater for ...?
3.3 How do I store chemicals?
3.4 How do I remove water marks?
3.5 How do I get rid of my old chemicals?
3.6 What's the difference between the various enlarger types?
4. Film processing
4.1 How do I process...
4.2 My Kodak Tmax film comes out purple - what happened?
5. What's the advantage of diluting developer?
6.1 Resin-coated of Fiber-based paper?
6.2 Can I use brand A VC filters on brand B paper?
6.3 I have a color head, can I print on VC paper?
6.4 Can I print color negatives on black-and-white paper?
Welcome to the rec.photo.darkroom FAQ. You should read this document
before posting to rec.photo.darkroom in order to prevent you from
embarrassments, such as asking questions that are answered in this
FAQ. This version of the FAQ is labelled $Revision: 1.10 $.
This FAQ is available on the World Wide Web, in several formats:
o HTML format <http://www.cdegroot.com/photo/darkroom-faq.html>
o SGML format <http://www.cdegroot.com/photo/darkroom-faq.sgml>
o plain text <http://www.cdegroot.com/photo/darkroom-faq.txt>
o PostScript <http://www.cdegroot.com/photo/darkroom-faq.ps>
If you have any problems, suggestions, or questions, please contact
the maintainer, Cees de Groot <mailto:email@example.com>.
1.1. I don't have access to the Web
``You're pointing to Websites everywhere, but I don't have access to
the WWW.'' Sorry, but I think that you are out of luck. To put it
bluntly, I feel that if you can afford to put time and money into
photography, you should be able to put time and money into the
greatest information resource on photography - the Web. Furthermore,
people expect you to have access to the Web, so they will respond
irritated if you ask questions on the newsgroup that are one click
away from this FAQ.
So do yourself a favour, and get a decent Internet account.
Jean-David Beyer for typing in the quote from Kodak's T-Max datasheet
:-). Tom Reed <mailto:firstname.lastname@example.org> for suggesting the
parts on VC paper (and supplying me with the table of filtration
1.3. Disclaimer, copyright
I've done everything in my power and limited time to make sure that
the information in this FAQ is correct. However, neither I nor any
contributors can be held responsible for the results of acting on this
information or for any damages resulting from using the information in
this document in any way.
Copyright (C)1997 by Cees A. de Groot. This document may be
distributed and reproduced without permission provided that it stays
intact, including this copyright notice.
(The copyright has my name on it because somebody has to own the
copyright; however, I want stress the fact that the actual
intellectual ``owner'' of this document is the collective readership
2. General information
2.1. What is rec.photo.darkroom all about?
Darkroom work. In the broadest sense. There are people here trying to
get started with developing 35mm film, people busy with alternative
processes, professional darkroom workers, etcetera. There are many
many topics which are discussed: materials, technique, equipment,
etcetera. There are some questions, however, which are better
discussed in other groups, like the quality of films
(rec.photo.film+labs) and buying/selling equipment
Here's the newsgroups line and the charter of rec.photo.darkroom:
rec.photo.darkroom Developing, printing and other darkroom
This newsgroup will contain postings related to all aspects
of photographic darkroom use. As such it will cover subjects
such as the developing of slide and negative film,
photographic printing from negatives and slides,
photographic toning processes and alternative chemistry.
This newsgroup specifically does *NOT* permit the posting of
commercial advertisments for products or services, even if
they are related to photography.
By the way, all the charters for the rec.photo groups are available on
Photo.net. Read them, before you post...
2.2. What is The Link?
I'm going to introduce a new saying on the rec.photo newsgroups: Use
The Link, Luke ;-).
The Link is The Guide to rec.photo FAQs
<http://www4.ncsu.edu/unity/users/j/jnweg/faq44.htm>, and is simply a
huge collection of pointers to other places. If you have any interest
in photography, you should definitely bookmark this place.
2.3. Your Mileage May Vary?
``YMMV'' is a well-known Usenetism to indicate that what works for me,
may not work for you. This is especially true in photography. Although
all photographic processes are subject to the laws of physics and
chemistry, there is such a large variation of factors you need to take
into account that it is impossible to say how something will work out
exactly in somebody else's darkroom. Add to that personal preferences
- what I call fine grain is horrible, golf-ball grain to the next guy
- and you'll understand that the only way to find out is to
Especially questions containing the words ``will ... make a
difference?'' are subject to this: probably, somebody with a well-
equipped lab having access to advanced measuring instruments will
always find a difference. But this does not matter. What matters, is
whether you will see a difference. So, rather than ask the Net, you
might as well see for yourself, because you're likely to get vague
Test And Experiment, you can only learn from it.
3. The darkroom
3.1. How do I build a darkroom?
There's an awful lot to say here, and it is all very dependent on what
kind of space (big/small, permanent/nonpermanent) you have. Kodak has
a lot of good, sound advice on darkroom building, and I'm aware of one
links covering the topic:
3.2. Can I use tapwater for ...?
Generally speaking: yes you can. The short answer comes from David
Manzi <mailto:email@example.com>, I quote:
Could you use it from a tap?
Yes you could, you little sap!
Could you use it for a mix?
Sure you could, without a fix!
Can I use it for a wash?
Absolutely, let is slosh!
But what about photo-flo?
Ooo I'm sorry, that's a no.
The general consensus is that normal tapwater doesn't contain any
chemicals in high enough concentrations to influence photographic
processes. This is assuming we are talking about water from a water
company - well water may very well be unsuitable for darkroom work.
The only exception is the final rinse with wetting agent (Photo Flo),
where hard water may still leave drying marks; here it makes sense to
use distilled water, water from an air dehumidifier, or bottled water
(if it is soft enough).
This is only a general consensus, people have been complaining about
their tap water's fitness for darkroom work. If you feel uncertain,
you might want to consult others in the area (minilabs), your water
3.3. How do I store chemicals?
A discussion that is coming up over and over again is what kind of
bottles are best used to store chemicals. The best stuff, but you
already knew that, is dark brown glass bottles with stops made for
keeping chemicals in and air out. Glass doesn't let air through and is
easy to clean, and these are the two most important considerations
(brown glass also doesn't let light in that could harm your
chemicals). These bottles are also the most expensive ones, so you
might want to use them only for chemicals that oxidize easily, like
Plastics are permeable to air, and not as easy to clean (chemicals can
and will be absorbed by plastic and it'll never get out). The cleaning
part is solved mostly by only using any given container for a single
type of solution. How much oxygen can get to your chemicals depends on
the type of plastic and its thickness (the thicker, the better). The
best solution is metalized plastic, then PETE, HDPE, LDPE, PP, PVC, PS
and last and worst Teflon. Here's an overview of plastics names, the
numbers that appear inside the "recycling triangle" on containers from
these materials, and what they're often used for:
1 Polyethylene terepthalate (PETE) soft drink bottles
2 High Density Polyethylene (HDPE) milk, juice and laundry product bottles, Nalgene laboratory ware and bottles
3 Polyvinyl Chloride (PVC) cooking oil, water, vinegar and bleach bottles
4 Low Density Polyethylene (LDPE) bags, margarine and ice containers
5 Polypropylene (PP) yogurt cups and ketchup and syrup bottles
6 Polystyrene (PS) clear: salad containers, disposable cups; expanded: insulating food containers
- (Poly)tetrafluoroethylene ((P)TFE) Dupont Trademark "Teflon"; laboratory and environmental sampling containers
(table and most of the information in this section from a posting by
Marc Hult <mailto:firstname.lastname@example.org> in rec.photo.darkroom, Message
3.4. How do I remove water marks?
A recipe by Richard Knoppow <mailto:email@example.com>, found in
"Try the following. Soak the film for a few minutes in plain water,
then treat it for a couple of minutes in stop bath. Swab the surface
gently with cotton swabs. If there is anything left treat it with a
wash aid like Kodak Hypo Clearing Agent for a minute or two and again
try swabbing. This should remove any deposits left by the Photo-Flo.
Then wash the film for five minutes and treat in a mixture of
distilled water with about one ounce per quart of rubbing alcohol
added (Mike Gudzinowicz correct this if wrong) and about half the
amount of Photo-Flow recommended by Kodak. Hang it up to dry without
3.5. How do I get rid of my old chemicals?
This depends on your local circumstances. If you're connected to a
sewage treatment plant, just down the drain with it. The stuff you
produce day by day on the toilet puts more load on the system than the
relatively small amounts of waste chemicals you collect in your
darkroom. It's more hazardous, too, to collect and store large amounts
of processed chemicals in order to bring them to a depot (if you have
one in your area). If you're unsure whether you're allowed to do this
(regulations may vary), contact the guys who process your water - I'm
sure they'll be more than happy to give advice.
People have reported no problems dumping chemicals into their septic
tank system, although some take the precaution to dump them together
with large volumes of water, eg. when the washing machine pumps its
water out. If you are not sure your septic tank will survive
photochemicals, contact your dealer (at the very least, you've got
somebody to sue :-)).
If you cannot or don't want to dump chemicals down the drain, an
often-heard advise is to collect it in a large cannister which you
leave open in order to have the water evaporate. You can then
regularly collect the crystals from the cannister and get rid of them
in whatever way you get rid of other dry chemical waste (which all
depends on local regulations). Take precautions against spilling or
leakage, like storing the cannister in a tray that can hold the volume
of fluid in the cannister.
Note that all these rules apply to hobby darkrooms only. If you're a
professional, you should contact your local environmental authority
and talk to them; most places have strict rules about chemical storage
and disposal for professionally-run darkrooms and photolabs.
3.6. What's the difference between the various enlarger types?
There are two main types of enlargers: diffusion and condensor
enlargers. The difference is in the type of light that hits the film:
a diffusion enlarger has a light mixing chamber and/or a diffuse
translucent panel in order to shed an evenly distributed, diffuse
light onto the negative. A condensor enlarger uses one or more lens
elements in order to produce a colliminated light beam focused on the
You cannot say that one type is better than the other - a lot of
photographers have taken foot in one camp and defend their type of
enlarger in an almost religous way, but you will be able to produce
good prints with both.
There are some objective differences due to the nature of the light:
o The specular light from the condensor enlarger tends to enhance
dust, etcetera, on the negative. You need to be more careful, but
it's not a very big deal. A condensor enlarger also tends to show
more grain in the print, but see the next point. On the other hand,
the images are a bit sharper, which makes them especially popular
for small formats like 35mm.
o The specular light also gives higher contrast. This is hard to
explain in just a few words, but it's a well-known effect
discovered by a Mr. Callier in the early days of this century:
specular light gives higher density readings than diffuse light,
and the ratio between these density readings is called the Callier
Coefficient. I won't go into the details, but it means you need to
shorten your development times in order to correct for this effect.
Shorter development gives smaller grains and this offsets the
higher grain from the previous point.
o Again due to the Callier effect, you will have a difference in
contrast between contact prints and enlarged prints with a
condensor enlarger: contact prints always show the diffuse
densities in your negative, condensor enlarged prints show the
higher specular densities. If you make a contact sheet, you will
usually need a higher paper grade for this contact sheet in order
to see the effect you'll get when enlarging the negatives. This is
not a very big deal - you can match paper grades quite easily (it's
normally one grade difference), and for good prints the grade
indicated by a contact print is just a starting point, anyway
(Ansel Adams used a very soft grade for his contact sheets in order
to get maximal information, thus completely bypassing this
4. Film processing
4.1. How do I process...
Did you check the manufacturer information? I don't mean the stuff
printed on the inside of the box, but the full information readily
available on the web or even as hardcopy? When starting with a new
film/developer combination, make sure that you get and read the
manufacturer datasheets of both developer and film first - most of the
manufacturers have datasheets available on the Web:
o Kodak <http://www.kodak.com/ciHome/products/L1/>, or call
1-800-242-2424 ext. 19 if you are in the US;
o Agfa <http://www.agfaphoto.com/products/index.html>;
o Ilford <http://www.ilford.com/html/us_english/homeng.html>;
o Fuji <http://www.fujifilm.com/>.
Then, there is an incredible amount of information about processing
film on the web maintained by individuals. A (very) short list:
o Photo Source <http://www.digitaltruth.com/>, with the Massive B&W
Dev Chart, a gigantic list of development times for a lot of
and of course: Use The Link, Luke.
4.2. My Kodak Tmax film comes out purple - what happened?
Tmax (and other T-grain films like Ilford Delta) have sensitizing dies
incorporated into the emulsion that cannot be washed out very easily.
If you don't follow processing instructions carefully, this
sensitizing dye gives a purple/pink/magenta hue. According to Kodak, a
slight hue doesn't influence printing, but if the color is stronger,
it adds to base+fog density.
First of all, get Kodak datasheet F-32. Via the Web (see above) or
from your photographic dealer. If you read the instructions carefully
and follow them, you won't have any problems. In a few words, you need
to dump your fixer earlier (because these emulsions exhaust them
faster), agitate vigourously when fixing, wash a bit longer, and use
Hypo Clearing Agent. As this is FAQ number one on the group, I'll just
"Fix at 65 to 75F (18C to 24C) for 3 to 5 minutes with vig-
orous agitation in KODAK Rapid Fixer. Be sure to agitate the
film frequently during fixing.
"Note: To keep fixing times as short as possible, we
strongly recommend using KODAK Rapid Fixer. If you use
another fixer, such as KODAK Fixer or KODAFIX solution, fix
for 5 to 10 minutes or twice the time it takes for the film
to clear. You can check the film for clearing after 3
minutes in KODAK Rapid Fixer or 5 minutes in KODAK Fixer or
"Important: Your fixer will be exhausted more rapidly with
these films than with other films. If your negatives show a
magenta (pink) stain after fixing, your fixer may be near
exhaustion, or you may not have used a long enough time. If
the stain is slight, it will not affect negative contrast or
printing times. If pronounced and irregular over the film
surface, refix the film in fresh fixer.
"Wash for 20 to 30 minutes in running water at 65F to 75F
(18C to 24C) with a flow ratre that provides at least one
complete change of water in 5 minutes. You can wash long
rolls on the processing reel. To save time and conserve
water, use KODAK Hypo Clearing Agent."
The Ilford datasheets for Delta films have similar instructions. If
you have films with these residual dies in them, re-fixing followed by
a long wash may help.
5. What's the advantage of diluting developer?
When you dilute developer, you change the chemical characteristics of
the various components. The two effects most cited are that you get
better sharpness, but at the same time slightly larger grain - both
caused by the suppression of silver solvent action. You also can gain
a bit more speed, and because of the extended developing times, it is
easier to get even and consistent development. Dilute developer makes
it economical to use it one-shot (throw it away after usage), which
further adds to consistency.
In howfar the effects of dilute developer are visible, depends on the
film/developer combination. When starting out with a new combo, test
various dilutions and see whether you can make out any differences.
Use what you like best.
6.1. Resin-coated of Fiber-based paper?
Which one you will use depends on a lot of things. First, the facts:
o FB paper has proven archival qualities (given proper processing).
That's why collectors, musea, etc. often insist on FB.
o RC paper has shown good keeping qualities in accellerated aging
tests. If it is just for yourself, friends and family, I think you
can rest assured that it will keep the rest of your life. But,
until RC paper has been on the market for another 100 years, it's
not called archival.
o RC paper is much easier to process. It is especially easy to wash
and dry, and it won't curl.
o FB paper is less sensitive to the temperatures in a dry-mount
o FB paper can be kept wet for a very long time, whereas with RC
paper, you risk separation of the layers.
Then the opinions: there are people who simply like the look and
feel of FB paper better. You should decide that for yourself, of
course. Invest in a small package of both, that will give you a
better answer than asking the newsgroup.
6.2. Can I use brand A VC filters on brand B paper?
Yes, but there might be small differences in the grades you get.
However, a #2 filter will always give a softer result as a #3 filter,
no matter on which paper you use it.
My humble opinion: the subtle differences of mixing up filters and
papers are probably smaller than the differences introduced by the
fact that you probably use another developer, enlarger and darkroom
than the factory test facility. So you need to test anyway (I test by
contact printing a step tablet).
6.3. I have a color head, can I print on VC paper?
Yes, you can. Again, get the datasheets of the paper - manufacturers
of VC paper normally have color filtration values for the various
grades. A starting point:
Grade 2 45M/9Y
Grade 2.5 65M/12Y
Grade 3 95M/15Y
Grade 3.5 120M/20Y
Grade 4 200M/30Y
Grade 5+ 200M
6.4. Can I print color negatives on black-and-white paper?
Yes, you can. Normal B&W paper, however, is not panchromatic - it only
responds to a narrow band of wavelengths of light. Graded paper just
responds to blue light, and variable contrast paper responds to blue
and green light (but the amounts of blue and green light influence the
gradation of the paper). Generally speaking, printing color negs on
B&W paper won't give natural-looking results.
Kodak has a panchromatic paper, Panalure, available in 3 grades. If
you want to get good results printing from color negatives, you should
use this paper.
Of course, using normal B&W paper can give interesting effects,
comparable with using orthochromatic film - experiment!
Cees de Groot http://www.cdegroot.com <firstname.lastname@example.org>
rec.photo.darkroom FAQ: http://www.cdegroot.com/photo/darkroom-faq.html
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