fb+f of ilford film

[mitch brown]

i am doing a film speed test for hp5+ and d100 and was surprised at what i think is a high film base + fog reading. for hp5+ fb+f is .12 and delta 100 is .10. are these normal? the measurements are made useing a 361T on the ortho chan.
thanks
mitch

 

[edtbjon]

That sounds normal. I've measured film (from a yellow box though) which was only a couple of years or so beyond it's "best before" date and the b+f was in the range of .40-.50 .

//Björn

 

[ic-racer]

I have been letting the kids use some HP5 from the early 80s. The measured fb+f is 0.73. There is a discrete loss of speed and latitude, but the film still "works" and produces printable negatives.