film speed of 800

[mitch brown]

i finished a film speed test using HP5+ and was surprised at the result of a FS of 800. this is the result of processing the film using a slosh tray with PMK developer for 13 min @ 70 d agitation twice every 15 sec . previouse i had developed using a dip and dunk methiod that produced a film speed of 250. does the use of the slosh tray the reason?.
should this bother me to have a higher film speed? any thoughts ?
mitch

 

[David A. Goldfarb]

I suspect an error somewhere. Unless you did some sort of low agitation or stand development, I doubt you would get an EI of 800 for HP5+ in PMK.

 

[hywel]

What gamma you get? Trying some film speed tests of my own recently I also seem to get fast results, but the gamma is (unusably) high as well:

I use ID11, at 1+1, for which Ilford reccomend 13mins at 20 deg for HP5 (35mm small tank). At 11.5 mins I got a speed, worrying about bf+..., of about 600. But with a gamma of 0.9. To get gamma down to something around 0.6 I need 8 mins, at which point the speed has dropped to about 250-320.

I've never tried any variations on developer or method but I would recommend repeating a test: of the five I did one was a long way away from the others. I don't know what happened--I made a mistake, different batch of film, saturday afternoon vs sunday morning?-- but you wouldn't want that to be the only one you did.

Of course the real test is how the negs print.