Question: about HC-110 Dil. B

[ilfordrapid]

I shoot Ilford Pan F Plus 50 ISO, 120 film, but I have rated it at 80 ISO, and I develope with HC-110 Dil. B (2:14) in a steel tank on a reel. The manufacturer says to give 4 minutes development, but I find that if I develop for 5 minutes that it raises the density of the negative and boosts the contrast, there is a very noticeable difference between 4 and 5 minutes, could this be considered a one stop increase in such a quick amount of time. I do not find the negative densities objectional. I think they would print well with a diffusion enlarger. Any comments, or suggestions?

 

[Lee L]

You've almost answered your own question. I can't tell you specifics about this film/developer combination under your conditions, but a 25% increase in time (from 4 minutes to 5 minutes) could easily be a one stop contrast expansion or more. 15% is often quoted as the increase in time for a one stop zone system expansion. You might go to a higher dilution and longer times to make the time more controllable if it makes you more comfortable.

I also can't recall if Ilford's published times are targeted for diffusion or condenser enlargement, but that makes a significant difference as well.

You just have to test under your conditions for what works best for you and your agitation pattern, printing paper, enlarger, paper developer, etc. Downrating film speeds is commonly needed with HC-110 at standard dilutions and times, so and EI of 80 is a reasonable place to start. It wouldn't be too unusual to use and EI of 64 or perhaps even lower.

Lee

 

[Eric Rose]

Hi there. I have used dilution H with good success. This is 1/2 the strength of dil B and double the time developing. This way you can fine tune + or - development better. To downrate a film you would go from 50 to say 32 asa. I have always found Pan F to be to contrasty for general use, but hey, if it works for you go for it.