How much developer needed to develop 2 5x7 inch films?

How can I figure out how much developer I need to develop two 5x7 inch sheets in a rotation tank.
Till now I just splashed 250 cc in the tank and it did the job, but maybe I can use much less or maybe I'm just on the lower limit? Is there a "common" guideline for this?

The developer I want to use is Pyrocat HD 1+1+100; 15 minutes with film Fomapan 100 13x18 cm.
This is 2(13x18) = 468 cm2

Many thanks in advance and a Merry Christmas

Sorry but found the answer in the Pyrocat HD in the mean time.
75 ml / 4x5 inch film or 250 ml for 1 8x10 inch film

Hi Hans,

Developer capacity is generally stated in the number of "sheets" that can be processed.

A "sheet" is one 8x10 sheet of film or any combination of film that can be proofed on a single 8x10 sheet of paper.
That means one 36-exposure roll of 35mm film or one 120 roll or four 4x5 sheets or 2 5x7 sheets.

- Leigh

Hi Leigh,

Thank you for your clear explanation.

Best regards

Hans

In addition to the chemical capacity, you need to have some concern for the nature of the tank itself. In some cases, even with constant rotation, 150 ml may be too little to ensure even coverage and development.

Thank you Matt,
Makes sense.
250 ml in the past was enough for D76 1+1
Because of 1+1+100 dellution I was wondering about the minimum amount.
According to what I found online 300 ml should be enough.
The tank is made for one 8x10 inch paper/film format.

There is a very good explanation of this in the Film Developing Cookbook, page 31. How much developer you need depends on the type of developer and the dilution you want to use.

Developer is cheap; better to have an excess than not enough.

Hi Jim,

I have the Darkroom Cookbook and found the same explaination as posted by Leigh.

Leigh B said:

Hi Hans,

Developer capacity is generally stated in the number of "sheets" that can be processed.

A "sheet" is one 8x10 sheet of film or any combination of film that can be proofed on a single 8x10 sheet of paper.
That means one 36-exposure roll of 35mm film or one 120 roll or four 4x5 sheets or 2 5x7 sheets.

- Leigh

Click to expand...

I don't know if there is a different advice in your book as I don't have that one.
Maybe you can give more details about what you found?

Anyway you are right about not saving to much on Developer.
however that is not the issue but to much waste is not good for our enviroment so I'm looking for a good balance.

Many thanks

Hans,

Regarding the amount of developer you need...

Most developers state the amount of film that can be developed using a bottle of concentrate, like 20 rolls or whatever.

That defines the amount of concentrate you must use per roll, regardless of what dilution and final volume you choose.

That is the only volume that has any environmental impact, since the rest of the working solution is just water.

- Leigh

I use the Expert tanks from Job and also the roll film tanks. In the 3006 tank I can start to have development issues if I drop below 3.5ml per square inch. So 4ml per square inch is a safety margin.

Two things can occur.

1. Some parts of the film may not get sufficiently immersed in the developing solution. This is something specific to the tank you use. I think the reel tanks can use less developing solution. Keeping an expert tank very level during agitation is very important.

2. There is a possibility of developer exhaustion depending on dilution and developing time.

As insurance, I use a long-lasting developer that is diluted to keep my costs lower.

swmcl said:

I use the Expert tanks from Job[o] and also the roll film tanks. In the 3006 tank I can start to have development issues if I drop below 3.5ml per square inch. So 4ml per square inch is a safety margin.

Click to expand...

In all cases, you must use at least the minimum developer concentrate as stated by its manufacturer.

This may influence the actual dilutions that can be used for a given tank and developer.

It may result in the volume of working developer being larger than the minimum required for the tank.
That's OK.

- Leigh

Hans Mulders said:

Hi Jim,

I have the Darkroom Cookbook and found the same explaination as posted by Leigh.



I don't know if there is a different advice in your book as I don't have that one.
Maybe you can give more details about what you found?

Anyway you are right about not saving to much on Developer.
however that is not the issue but to much waste is not good for our enviroment so I'm looking for a good balance.

Many thanks

Click to expand...

Hans, this is (I believe) the 1st editon of FDC by Anchell & Troop, 1998. Here's the page:
8x10 film or 80 sq. inches =
1) 35mm roll, 36 exp.
1) roll 120
4) sheets 4x5
2) sheets 5x7
1) sheet 8x10

"Although it is true, as Kodak claims, that 100 ml of UNDILUTED D-76 is sufficient to develop 8x10 inches of film, it may not always be enough to develop the film to its fullest potential. The amount of solution required to cover the film's surface should not be confused with the amount of developer required to fully develop a roll of film.

For example, 100 ml of solution will cover one roll of 35mm, 36 exp. in a JOBO CPA-2 processor. However, to ensure full development of all images on the roll at least 250 ml of undiluted D-76 should be used, no matter what any manufacturer says to the contrary.

To maintain qulaity and consistancy use the following volumes each 8x10 inches of film, regardless of the processing method, even rotary processing.

Undiluted developers: at least 250 ml of D-76, Microdol-X, Xtol,

Dilute developers: at least 500 ml of D-76 1+1, Rodinal 1+25 and 1+50, , FX-1, FX-2, HC-110 1+31 and PMK.

Very dilute developers: use 1 liter of D-76 1+3, Rodinal 1+100, FX-2 1+1, HC-110 1+90.

These amounts may sound extreme to some, but saving on developer is penny wise and pound foolish. Do not try to make photography cost effective by skimping on developer. You'll never be able to maintain quality and consistancy, even if the results appear adequate."

This is advice I take. If I'm wasting developer, it isn't much and I pefer to think of it as an investment.

I use a lot of Pyrocat HD and use the PMK dilution above. No complaints.

There are two unrelated conditions that must both be met:

1 - The amount of active developing agent (chemical) used must meet or exceed the amount spec'd by its manufacturer.

2 - The volume of working developer solution must meet or exceed the amount required to fully cover the emulsion.

With rotary tank processing, the total volume (#2) is much less than for vertical tank or tray processing.
But the minimum amount of developing agent (#1) does not change with processing method.

- Leigh