Chemical to paper ratio in developing trays?

[cantore]

Is there is a certain amount of chemicals (Developer & Fixer) that you should fill the trays with based upon how many prints you expect to process? When i print i use Ilford Mg developer 1+9 that gives me 20 ounces of developer (2oz developer & 18oz water). I also use Kodafix at 2.5oz Kodafix & 17.50z water. When i make an 8x10 print i usually go through about 6 sheets before i like the print. i know the developer is fine because i have not seen any difference of development from the 1st to the 6th print but i dont know about the fixer. Is there a certain amount is should use based upon how many print i expect to do? Thanks!

[ROL]

To my knowledge, all commercially available chemicals have per square inch or number of some size sheets for safe use before exhaustion occurs somewhere in the fine print. Just observe the manufacturers recommendations and you'll be fine.

If you're asking a very searchable question of how much liquid to use, you only need enough to cover the print or to make sure multiple prints can swim freely.

[MattKing]

The volume of chemistry I use in my trays depends on the trays themselves and the size(s) and numbers of prints I am doing.

If there is a chance I will be developing prints in batches (2, 3, 4 or more at a time - think Postcard Exchange) it is much easier if there is a lot of volume in the tray.

If you start out with a small volume, you can always replace chemistry, or just add more when the capacity numbers are reached.

In most cases, chemistry is the cheapest element in the process.

[David Allen]

The amount of fixer you require is based on a ratio between how much you need to fully immerse the print and the number of prints you want to process. The effective capacity of the fixer depends upon:

Commercial printing: approximately 40 prints at size 10" x 8" (or equivalent) per 1 litre of working strength rapid fixer.

Archival printing: requires regular testing as the maximum safe level of silver in the fixer for effective archival fixing is 0.5 grams/litre.

Archival printing (more economical approach): use the two fixer bath approach. In this system the first bath can contain up to 2 grams/litre of silver upon which it is then discarded. Once the second bath has reached a level of 0.5 grams/litre of silver it is transfered to become the first fixer bath and a new fresh batch of fixer is mixed up to become the new clean second fixer bath.

All sound far more complicated written down than in actual practice.

Best,

[markbarendt]

http://ilfordphoto.com/Webfiles/2011427123181979.pdf

See page 3 for developer capacity.

[Thomas Bertilsson]

I use a gallon in each tray when I print, irrespective of print size up to my maximum of 16x20".

My developer is replenished, so I add 300ml for every 30 8x10 prints (or equivalent).

And that's that...

If you use a regular print developer that isn't replenished, follow the link Mark Barendt posted above.

[keithwms]

Is there is a certain amount of chemicals (Developer & Fixer) that you should fill the trays with based upon how many prints you expect to process?

I usually have a good inch or so of developer over the print, which allows me to run through at least ~10 prints with no changes in times or results and allows me to agitate easily. I didn't do any math, it just seems to work out that way.

[pgomena]

I'm with Thomas. If you're settling in for a long stretch in the darkroom, start with a gallon of working-strength developer. Add a little more stock after you've finished each set of prints from one negative. Pitch the whole thing when you're done for the day. You'll never suffer from developer fatigue. Obviously, if you're just making one print, you can start with less working solution, but I'd never work with less than a quart/liter.

Peter Gomena