[Adrian]

I recently shot a roll of FP4+ at box-speed and inadvertently ended up closing down by 2 stops for 10/15 shots until I'd realised what'd happened. Oops. So, I thought I'd wasted most of the roll.

I developed the film in what I thought was ID11 1+3 for 18.5 mins (21C)(having found I didn't have enough of what I thought was 1+1, so I added extra water to make up to 1+3.)

When I looked at the contact sheet, I was amased. The frames that should have been nearly black were a bit underexposed (~1/2 stop) but usable. The remainder of the frames looked fine, if a little contrasty. Upon printing, I didn't like the contrast so printed at 1 grade lower. I also noticed grain. I thought, 1+3 ID11 and FP4+ should be very fine grained. So, what had happened? I'd rescued the roll of film, got more contrast and grain, but neither contrast nor grain were excessive. I must have pushed the FP4+ unintentionally.

When I thought about what I'd done, I realised I'd mixed stock (not 1+1) with 2 parts water: effectively 1+2 and pushed it to 18.5 mins dev time.

So the lessons learned are:
1. Always read the label even if it's written by oneself!
2. 1+2 and 18.5 mins is a potentially useful rescue remedy for a 2-stop underexposure of FP4.