Rodinal exhaustion rate

[Russ Young]

Can any Rodinal user give me a guideline for how many square inches of film can be developed by a cc of Rodinal?

Thanks.
Russ

 

[gainer]

I think 20 is a conservative number.

 

[david b]

I've done 2 rolls of 120 in 1+100 (990ml water and 10ml Rodinal).

 

[Ian Leake]

Isn't it supposed to be 10cc for 1 sheet of 10x8 (or one roll of 35mm)? That would make 8 square inches per 1cc.

 

[Lee L]

There are other threads on APUG that mention different common usage rates, so a search might come in handy. I've used 3cc per 135-36 or 120 roll (equivalent to 8" x 10" in area) at 1:100 dilution for over 30 years with consistently good results. I always do one shot development per batch. I think 10cc is the official Agfa recommendation as Ian mentions, but that recommendation is routinely violated (with great results) in practice by a large percentage of users.

Lee

 

[titrisol]

As Lee said 3 ml (1+100) is enough for a 135/36 roll so that should be 24x36x36 mm2 ~ 310 cm^2 without sprockets or spacing so closer to 320 cm2.
1+100 works well with 120 (432 cm2) as well, but more solution is needed
I have neer tried it in 8x10 (20x25 cm ~ 500 cm2) but if I were to follow the simple rule 1ml of Rodinal per 100 cm2 then I'd use 5 just to be sure.

 

[George Papantoniou]

The problem with this kind of reasoning and 8x10 film is that while on a 35mm film the images are usually 36 and the subject matter usually varies between them, so you can calculate an average developer strength to develop one roll, on a 8x10 sheet you have only one image, so if it's a low-key one then you need less active development ingredients in your soup, if it's a high-key one then you need more...

 

[titrisol]

Valid point form George, in that sense 6ml should be safe as a minimum