Ilford Delta 100 @ 125

[SolaresLarrave]

When it's exposed/rated at ISO 100, it's souped in D-76 (7 mins) or T-Max (6 mins). What if it's (accidentally) rated and exposed at ISO 125?

BTW, those are the two developers I have.

Thanks in advance for the suggestions! 🙂

 

[peterc]

D-76 at 1+1 for 11:45 or 12 minutes should be pretty close.

 

[Bob Michaels]

What if it's (accidentally) rated and exposed at ISO 125?

Are you sure that you meter accurately enough so that this 1/3 stop makes a difference? I would say that this is well within the latitude of the film. I'd just develop it the same way you always do if you normally shoot this at 100.

 

[SolaresLarrave]

Bob, that was exactly my first thought... These two rolls were used in snowy scenes, so I believe a little bit of overdeveloping might do good, but then, the difference is so small I wonder if it's really necessary.

Thanks a lot 🙂 !

 

[MikeL]

Francisco, how did you meter the snowy scenes? Also, I use Delta 100 with my IIIs and if the shutters are within half a stop I'd be surprised. Haven't had too much of a problem with exposure.

 

[SolaresLarrave]

For snow, I overexposed one stop.

See, rating the film at ISO 125 was accidental. I thought I was loading FP4 (whose 24-exposure canisters are the same color as the 36-exposure Delta rolls). I guess that gives the snow a bit more overexposure... which is fine with me!

 

[rich815]

For snow, I overexposed one stop.

See, rating the film at ISO 125 was accidental. I thought I was loading FP4 (whose 24-exposure canisters are the same color as the 36-exposure Delta rolls). I guess that gives the snow a bit more overexposure... which is fine with me!

Actually shooting a 100 speed film at 125 it will be slightly underexposed.

 

[MikeL]

Last week I thought I had a Delta 400 roll in my Nikon, and it was a Delta 100. I pushed it just a stop since is was sunny and the results weren't too bad, but I probably should have pushed it another half or so. Show us how yours turned out when you can.

 

[Chris101]

Actually shooting a 100 speed film at 125 it will be slightly underexposed.

I believe he meant that he intentionally gave the film one stop additional exposure so as to place the snow into the upper brightness levels (whereas the meter would try to put snow close to middle gray.)

Then he underexposed accidentally by a third of a stop by incorrectly setting his meter. Sum the EC values and he has overexposed by 2/3rds of a stop instead of the intended 1 stop.

According to the Massive Dev Chart, the speed of Delta 100 can be doubled (ie one stop) by increasing the time of development by two minutes with d76 1:1, from 11 minutes (for iso 100) to 13 minutes (for iso 200.) Thus, as peterc said eleven minutes, forty five seconds ought to increase the speed by those two thirds of a stop.

 

[skahde]

Don't mess with what worked for you on the processing side and just ignore that puny 1/3rd stop. Increasing the development time will have more effect on contrast than speed. And if you increase to much: blocked highlights, still empty shaddows, nightmare to print. :bang:


Short version: just ignore it.

Stefan

 

[SolaresLarrave]

Thanks, folks! I'll process it as if it were exposed at ISO 100 and tell you about it. 🙂