Puzzled by something I read in "The Darkroom Cookbook"...
In the "Developer volume" section of the book Anchells (p.73) suggests to use not the traditionnally recommended 150 ml of undiluted developer per film but at the very least 250 ml if you want your film to be fully developed.
That means that if i'm not mistaken that I should not use my Paterson 8-reels tank to the max of its capacity but that I should fill it with only 4 or 5 reeled films (plus 3 or 4 empty reels) for the same amount of developer (1200 ml of D-76 plus 1200 ml of water).
It'll immediately double the amount of time I'm going to spend in the darkroom so I'm quite wary of doing this... (yes i'm lazy)
Do you have an opinion on Anchell's advice?
Last edited by Pat Erson; 06-25-2011 at 09:56 AM. Click to view previous post history.
I believe the answer depends on the developer you are using.
For example, Kodak says to fully develop a film (say one canister of 35mm 36 exp or 120 = has the same area), you'll need 8 oz of D76 full strength or 4 oz of XTOL. Going only from memory, Kodak says to extend the dev time by 20 or 25% if you are using 4 oz of D76. Otherwise, it shouldn't matter as long as the developer covers full fully.
Develop, stop, fix.... wait.... where's my film?
It depends entirely on the developer and the dilution and is related to the effects of exhaustion.
So if you use Xtol, ID-11/D76 or Perceptol at 1+3 you need excess developer, giving an exact figure only works for a specific developer. If you know the formula the rate of exhaustion can be calculated.
The issue really becomes a problem in rotary processing with dilute developers because they use smaller volumes in the first place, the optimum is to used a replenished developer because exhaustion is negated.
To extend the useful capacity of D-76 Developer diluted
1:1—when processing two 36-exposure rolls in a 16-ounce
tank—increase the recommended time by about 10 percent.
That is straight from D76 Tech Pub.
I've found 150 mL of D-76 stock solution (plus matching water) to be adequate for 35mm films. It flies in the face of Anchell's assertation but it works for me, and it's more practical.
The best way to know is to test. Develop one roll with 150 mL of stock (plus matching water) and another with 250+250. See if you can discern a difference. If you can, stick with the latter.
Jim MacKenzie - Regina, Saskatchewan, Canada
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That 150ml figure may be fine for average subject matter, but fail on high key work or a larger format, or negs which require a higher contrast, 35mm has a lot of rebate and sprocket holes, it's taken as a very rough equivalent of a roll of 120 or 4 sheets of 5x4 or one 10x8 but reality is it'll exhaust developer less.
These are rules of thumb, it's what works for you, and that might not work for others.
IMHO, if the leader of 35 mm film, or fully exposed film of any size, masks photo paper enough to keep it from showing density at your standard printing time, then your development was sufficient. (Standard printing time is the exposure time that it takes to create a convincing black with a clear piece of film in the negative carrier, at a given enlargement magnification., and given development type and time. If you were to move the leader into the carrier, the paper should remain white after development.) I have always used 16oz, about 500 ml, diluted at at a given working strength, for 2 rolls of 35, and 1 roll of 120 (due to tank depth). I think 150 ml could exhaust prior to the completion of development. (When my students us plastic tanks, I tell them to use 12 oz of working strength developer, about 350 ml for a one roll tank. It does seem that 150 ml is too little developer at working strength. However as the others have said, if you are satisfied with the results your getting, given your personal variables, them you are good.
Belated thanks for the replies!
Post-scriptum : I just processed a bunch (16) of TRI-X films in D-76 at 1+1. Since I only had 2 liter left of stock D-76 instead of the (150ml x 16 =) 2.4 liters required to process the sixteen rolls well I simply added more water to fill the tanks (1.4 l per tank instead of the usual 1.2 l). So I was below the "1 part of dev. 1 part of water" rule.
The result? The films came out great. Absolutely no difference with the 1+1 procedure that i usually strictly enforce.
So it seems that yes you can forego this Anchell's rule
Is the reference to p. 73 from the first edition? I skimmed the second edition and didn't find anything on this issue. I have the third edition, and found this general discussion of dilution and volume on page 40-41.
This thread is leaving out a lot of what Anchell writes in the third edition. First, the 150 ml minimum volume of undiluted developer was determined by Kodak Research based on the minimum volume required to cover and develop the surface of 80 square inches of film using a Versamat machine processor (which moves the film on rollers through the processing baths) when maximizing profits to the last penny. Kodak also stated that 250 ml of undiluted developer per 80 sq/inches of film gave better results in the Versamat and should be used for best quality and consistent performance. Anchell simply extends that advice to a recommendation to always have more developing agent than needed so that you don't have to deal with the effects of possible developer exhaustion as a factor that affects consistency of results. This is a "best practice" recommendation by Anchell, and as such it's not really right or wrong. It's just designed to protect you from the effects of one variable (developer exhaustion). If the developer is really exhausted, extending development time won't buy you much.
All Anchell is saying is that you should be careful to use enough developing agent to avoid ill effects from developer exhaustion.
The effects of developer exhaustion can't be judged visually by looking at negatives, all the major companies have given minimum volumes over the years for good reasons, once the developer becomes exhausted the shows detail keeps developing due to developer already in the emulsion but in the exhausted highlight areas details become lost.
It may be that the effects of the exhaustion may not be an issue for some peoples work but I can assure you that's not always the case.