Film number 7
HP5+ @ 1600 ISO, DD-X 13 minutes at 20C
This is my first experiment with push processing; +2 stops. And, I'll be honest, the first film where I think things have not gone completely to plan - and I don't know why. The film, especially the early frames, looks rather thin to me, that was my first impression when the film was hung up to dry, and is still my impression now. It doesn't really come across in the contact sheet. All of the frames seem to me to be perfectly usable, despite whatever I may have done wrong - and this is an excellent demonstration of the latitude of film and its rather forgiving nature.
The most likely mistake is just exposure errors in those early frames (up to the compass shots), but everything just looks a bit "thin" (can't really think of a better description). Comparing at a general level to earlier 400 ISO films, and specifically the frames with the same content of our kitchen Welsh Dresser shelves, it looks to me to be about one stop underexposed. I doubt I messed up the exposure generally, but perhaps I did.
I have rechecked the meter readings, and the camera looks fine. I have rechecked the data sheet, but 13 minutes in DD-X looks right for HP5+ at 1600 ISO. I double checked that with the Massive Dev Chart, that was in accord too.
I did think maybe it was a temperature problem - I use a water bath to control the temperature of all the chemicals to 20C, but have not been temperature controlling the tank itself. I took the tank out of our rather cold garage just prior to development (with the film already loaded), perhaps it was 10-13C. I did wonder if that might have caused the temperature of the dev to plunge from 20C to maybe 16-17C, and that might explain the under-exposure, since the 13 minutes would have been appropriate for 800 ISO instead at that temperature. But, I just did an experiment with the cold tank and 300ml of water at 20C. I checked the temperature every minute for ten minutes or so until I got bored - it didn't budge, clearly the plastic of the tank is an excellent insulator. So that is not the explanation alone.
I have another film part way through in the camera that is also rated at 1600 ISO. I will pay special attention to the exposure of the final dozen or so shots. I shall also be very careful with mixing the dev, temperatures and agitation.
They do say that we learn more from our failures than our successes - but that only works if you know what went wrong!
Has anyone seen anything similar?
Here is the sheet