Devsloper volume

[Tony-S]

I'm about to purchase some Perceptol to restart my film developing (after more than 20 years of NOT doing film) and I cannot recall the typical volumes that my 120 tank takes. My tank is stainless steel and can accommodate one 120 or two 35mm reels. For some reason, I have in my head that it's:

12 oz/350 ml for a 120 reel
8 oz/230ml for one 35mm reel
16 oz/460 ml for two 35mm reels

While it would be easy to just put a reel in and measure with water, that does not account for the volumetric displacement of the film (which may be inconsequential?). I'd appreciate verifications or corrections from those of you in the know.

TIA.

 

[bdial]

I always fill the tank, regardless of the film size or number of 35 rolls, my tanks hold 16 oz.

 

[Tony-S]

Thanks for that info - but what is the rationale for filling the tank completely?

 

[Ian David]

You need to ensure that you have enough developer in the tank to:
1. cover the films on their reels with sufficient margin that any foam or bubbles on the surface won't affect the roll (don't worry about the volumetric displacement of the film when measuring - it is not great); AND
2. properly develop your film (look at the online data sheets for your chemistry to see how much developer is required per film).
Steve Anchell in his book advocates a "more is better" approach, using at least 250ml of undiluted developer per film...

Ian

 

[Tony-S]

Alright - that sounds like the plan; I'll order accordingly. Thanks for the input.

 

[Ian David]

I should just clarify one thing - when Anchell said "undiluted", he meant normal working strength (ie he didn't mean straight out of the concentrate bottle!)
Have fun!