Minimum volume of developer

venchka

venchka

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I'm trying to work out various dilutions for 4x5 film in JOBO tanks. My primary developers of interest are: D-76, XTOL and Rodinal. Assume a standard film unit of 80 sq. in.

I can get minimums from Kodak. Are these conservative or real minimums?

I have seen various minimum figures for Rodinal. I can't seem to find them, so I'll ask again. What is the minimum amount of Rodinal for 80 sq. in. of film?
 
Wayne:

I have a JOBO and the min. volumes are listed on the developing cannisters, aren't they? I seem to remember it's 250ml of diluted developer per roll for the expert drums.

Is your question about the minimum total developer volume per processing session or the minimum amount of stock developer per roll? FWIW, the constant agitation of the drums brings a lot of molecules of developer into contact with the film. When I started using the JOBO, I found the amount of developer that I was required to use was counter-intuitively small.

FWIW, I develop 8 36-exposure rolls of Delta 400 in one liter of diluted Xtol (1:1) and they come out just fine. Just to be clear: 500ml of stock plus 500ml of H2O. Same ratio for large-format negs, measured by square inches of film.

Note: if I was developing a single roll of film, I'd stick to the 250ml minimum to make sure that the depth of standing developer in the horizontal tube covered the film as it rolled through.



Ben Marks
 
Thanks Ben. That's good news. I was asking how much developer per 80 sq. in. in a diluted solution. Based on your 8 rolls/500ml XTOL, I could put 10 sheets of 4x5 in 160ml of XTOL + 160 ml of H20, rounded up. I wouldn't have a problem with using 250ml XTOL + 250 ml water. That appeals to my "belt & braces" approach to most things.

Does anyone have any good numbers for Rodinal?
 
Wayne:

I guess the only thing I would add is that you have to do your own testing. I found Rodinal to be very sensitive to ground-water pH. I worked for a small newspaper in a desert town with limestone aquifers, and found that I could not extend my development time enough to produce any results worth printing with Rodinal. D76 and Accufine worked fine, though. If you go that route, I suggest you run tests with distilled water. In fact, the experience was notable enough that I now only used distilled water for my developer. For one thing, it removes a major source of potential inconsistencies as distilled water has the same pH everywhere ;-). Now I live in Vermont and my water comes from a well and treated with a water softener. I use this well water for mixing chems other than developer and for rinsing.

The constant agitation of rotary processing is going to decrease your development times compared with small tank invert-and-bang agitation. The JOBO has good temperature control, so that takes care of another major variable.

When I am testing out a new developer in the JOBO (currently using a home-brew developed by Patrick Gainer that uses phenidone, Vitamin C and Red Devil Lye), I shoot a bunch of bracketed images of a grey card (marking the exposure indicated by a trusty hand held meter) and run a test roll through development at my "best guess" time. Then, when the film is dry, I scan or print the roll to show the best middle grey (after the sproket holes have disappeared -- or are barely visable -- on my contact sheet). I then adjust the development time up or down based on how many stops overexposed or underexposed the grey card is. This becomes the "normal" development time for a particular film/developer combination. All temperatures are a constant 68F. The rotary speed is always constant on the JOBO ("F"). The developer is always mixed with distilled water.

Good luck!

Ben Marks
 
Lately , when I'm using Rodinal at high dilutions, I figure that the lye (NaOH - KOH) is so dilute it may be ineffective, I add a pinch of NaOH to make sure the pH is high enough to make the p-minophenol works. Just a thought.

plus I use de-ionised water from the local automobile supply house. Much cheaper then distilled water.

Murray. Brisbane.
 
Last edited:
Minimum Rodinal from AGFA

Minimum Rodinal from AGFA

Even if AGFA is gone, the Internet still remembers:

wolfgang holz, May 15, 2001; 02:09 a.m.

Dear Dan,


<p>


in our technical data we mention that 500 ml concentrate of RODINAL will last for 50 films (135-36). That means that you need 10 ml concentrate to process 1 film. It does not matter what the dilution is. Important is that you are using 10 ml concentrate. For example if you are processing with a dilution of 1+50 than you need 10 ml concentrate plus 500 ml water so that you will have in total 550 ml solution to process your film. Why is it importatn to take 10 ml because these 10 ml contain the amount of substances which will be used to process your film correctly and with reproducible results. It can be that you will get good results with less than 10 ml as mentioned in one answer but to be sure we recommend 10 ml. I hope this will answer your question. If you have further questions please do not hesitate to contact me.


<p>


Kind regards Wolfgang Holz Product Manager Marketing Chemicals


<p>


Agfa-Gevaert AG

wolfgang holz, May 15, 2001; 08:50 a.m.

Dear Dan,


<p>


although I mentioned the amount of concentrate which is needed for a 135-36 the quantity will be the same for 8x10 film since the unit of square measure is near the same - 551 cm² for the 35 mm film and 516 cm² for the 8x10 film. The correct ammount would be 9,36 ml concentrate but I think to measure this might be a bit difficult.


<p>


Kind regards Wolfgang Holz
Click to expand...

10ml per 8x10 equivalent may be overkill. Rodinal is cheaper than loosing valuable images. I reckon being wrong on the high side is better than being wrong on the low side.

So, here we go. For 6 sheets of 4x5 film in either the JOBO 2521 with 2509 reel or the 3010 Expert, 1:50 dilution:

15 ml Rodinal + 750 ml water and Bob's your uncle! :D

D-76 (60ml min.) and XTOL (25 ml min.) recipes are already known.

That's my story & I'm sticking to it.
 
I got good results using Rodinal and constant agitation (colorol system), for 135 36exp and 120 roll film (I donno about square inches) I used 1ml of Agfa Rodinal and 200 ml of boiled and cooled tap water. Development time was about 37min, aprox @23C, for 100 ISO film shot @EI80. I tried 0.7ml of Rodinal plus 200ml of water and increased development time, but found resulting tonality (curve) not good for printing (though it may be improved in software) and I suppose there was some lose of details in shadows despite longer development. If I use Rodinal (not really often 'cause I prefer dual bath metol developer) I stick to 1ml plus 200ml. If put more Rodinal I ended up with too contrast negatives to my taste - pay attention I'm talking about constant agitation, i.e. it's kind of exhausting development when at each time some film goes into developer and other part of film goes out of solution. For normal hand developing tank process Rodinal deluted 1+50 usually works fine.
So, in a nutshell, 1ml of Agfa Rodinal is enough for one roll film, using less than 1ml you're under risk. That's result of my non-scientific practical tests.
Eduard
 
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