FP4 as HP5

While I was on my mini-break I raided my film stash for 400 speed film. I felt sure I’d need it, and I was correct! I ran very low, but in the end I returned home with half a dozen exposures left on the last roll.

It seems to be a “thing” these days of pushing HP5 two stops to 1600asa. The thought crossed my mind, what would happen if I did that with FP4? If I did, technically I’d end up with a 500asa film.

A did a little research on timings for that. Massive Dev chart offers 9.5 mins, with Ilfosol at 1+14, a weaker solution than I normally use, but at 24 degrees, warmer than I normally use. I also looked at the regular time for FP4 in Ilfosol 3 at 20, and a few other times too. In the end I decided that I’d expose a roll of FP4 as if it were HP5, in other words 400asa. I’d then develop it in my usual solution of Ilfosol 3 but at 1+9, at 20 degrees. These are the results I got.

A few observations are that first, just looking at the negs on the lightbox I got what I call a “good set of negs”, in other words nothing obviously too thin or heavy, not flat or too contrasty. Secondly they scanned well, the images presented here have had very little work in photoshop. Third the grain is not too strong. I was expecting the grain to be higher than it is.

In summary, if I ever need 400 speed, but don’t have any, I’ll be quite happy to repeat this process without worry. It’s not been a scientific test, but based on this I’m not sure I don’t prefer this to HP5! I guess you could say this is nothing new and is just pushing a film two stops or N+2, and I guess that’s so, but it’s not something I’ve tried before. For me, it’s been a useful play!

As a footnote I decided to try this, at the West Moors Country Park, a walk I take regularly, so that if it all went wrong, I wouldn’t loose anything thing that I couldn’t repeat. About 20 mins in it started to rain, so the film speed was useful. Then the rain got heavier. The river and then the lake had burst it’s banks and covered the path. I was past the point of no return and the water was over my shoes more than once! Above the river is to the right, on the left should be the path! Below look at that rain! Below again, there’s a path there somewhere!!