Development Brain Teaser

Hello All,

I bring you a brain-teaser of sorts. There is a real-life situation involved, but consider this just a mental exercise.

A fellow would like to develop three rolls of film simultaneously in the same tank. One roll is in 120 format and the other two rolls are 135 format. The 120 roll is Ilford FP4+ and it was exposed at box speed (125). The other two rolls are Ilford HP5+ and they were exposed at EI200, and should be pulled one stop in development.

The fellow has D76 developer handy and would like to find a dillution, temperature, and time that would satisfy the given development requirements.

Of course, by the time this fellow posts this and waits for responses, he could have run both formats, individually. Anyone care to run the numbers?

- Wayne

D76 1+1 for 11 minutes would be right for both according to DigitalTruth.

Though the Massive Dev Chart doesn't show HP5+ at 200 in D-76 1+1, it does show 11 minutes for ID-11 1+1 and both films, the time is the same 11 minutes.

In general, when faced with a "last few rolls" of different film to develop, I'll pick a compromise time that will "not hurt anything" but in this case, the times are the same.

http://www.ilfordphoto.com/Webfiles/2011427133131459.pdf ID-11 and D-76 are functional equivalents.

So, the real question becomes how are you printing?

Fixed grade paper: develop separately.

If otherwise: sure you could use the time for FP4 and adjust contrast when printing.

I print with multigrade FB paper and contrast filters... It shouldn't be too much of an issue. I use the Massive Development Chart as an app on my iPhone, but I did not think to check with the times for ID-11.

Thanks guys!