View Full Version : increase development time with re-used developer?

30-Jul-2010, 10:22
Hi all,

I did some searching earlier today and found, in the archives, the information that one roll of 35mm film is more or less equivalent in area to 4 sheets of 4x5 film, so that if one preparation of a specific developer is supposedly good for 10 rolls of 35mm, it will be good for 40 sheets of 4x5. Unless I've totally misunderstood things?

However, what I haven't found is information about extending development time for re-used developer. I used to use one of the Ilford developers (sorry, it was 10 years ago so I don't remember what type it was) that came with a chart or table or text about increasing development time by X% for each successive roll of 35mm film.

I now use Tetenal Ultrafin Plus, and neither the bottle nor the information on the web say anything about that. Does Ultrafin Plus not need longer time as it gets more and more used? Or am I just not looking in the right place? Many thanks for any help you can give me!

Best regards

Gem Singer
30-Jul-2010, 11:00
It's a good idea to use a working solution of film developer in a small tank or tray only once, then discard it (single shot).

Once diluted with water, a stock solution of developer becomes a working solution and begins to oxidize.

Sometimes, I develop a second batch of film in the same tray or tank of working solution and add an additional 30 seconds to my total developing time before discarding it.

However, I develop the second batch shortly after developing the first batch and am careful not to exceed the capacity of the developer.

The answer to your question is yes. Increase the time for re-used developer, but be careful not to over use it.

31-Jul-2010, 04:26
You can get extended use from t-max developer by increasing the time. But I just use it one shot with a volume based on the non-extended time to ensure even rotary development. http://www.kodak.com/global/en/professional/support/techPubs/j86/j86.pdf

2-Aug-2010, 00:10
Thanks, Gem Singer and ic-racer! Strange stuff this weekend... the batch of developer from two weeks ago is still clear, but too old to re-use. Mixed up some more, used it, and overnight it got horribly cloudy, it has about the visual density of skim milk. It worked fine on the negatives, and it was crystal clear even after I used it, but at some point overnight it, well, curdled. I'm definitely not using that batch again.


Bob McCarthy
2-Aug-2010, 07:07
I thought the sq inch equivalent was closer to 2.5 sheets of 4x5 per roll of 35mm.

Roughly 20 inches per sheet vs. 50 sq inch per roll.


Gem Singer
2-Aug-2010, 08:06
According to S. Anchell and B.Troop, "The Film developing Cookbook", top of pp.31:

1-35mm roll, 36 exposures = 1 sheet of 8x10 film (4 sheets of 4x5).

1- 120 roll = 1 sheet of 8x10 film.

Actual measurements may not be exactly 80 sq inches, but equivalents are very close.