Development times for medium format FP4 at 100 in Xtol?

[atomicthumbs]

I've checked the Massive Dev Chart, the Ilford chart, and other places, but I can't find any times for this. I'm using Sunny 16 on a camera whose only shutter speeds are 1/25, 1/50, and 1/100, and it'd be much easier to develop it at 100 than at 125. Does anyone know good times for this? Will it make a significant difference if I shoot at 100 and develop in 125?

 

[heespharm]

No not that much.... You could change ur time from a iso 125 base about 2-3 percent but in the end it won't make much difference

 

[Bob-D659]

The difference in shutter speed is about 1/3 stop. Probably less than the variance in the shutter speed from snap to snap. I wouldn't worry about it at all, but you should do some test shots to see if your shutter speeds are even close to the labeled value.

 

[rawhead]

Besides, FP4 turns out better when shot @ ISO100 (and developed as ISO125), IMHO

 

[Aurum]

Ilford Dev chart PDF here

For FP4 in straight Xtol @ 20 Degrees C, you're looking at 8.5 minutes @ EI 125, 10 minutes at EI 200. The difference between 100 and 125, especially when you're judging exposure by sunny 16 isn't worth mentioning

 

[George Collier]

What the others have said, plus, you are looking for a combination exposure and development that works with your equipment, methods, agitation, etc, so it's close enough to start. Evaluate exposure by shadow value quality and development by contrast, after printing. It's pretty personal, after the basics.