FP4 plus + Ultrafin liquid - time?

[dawid]

Hello all, first time being here. I need an advice, guys. I shot a roll of HP4 plus at ISO 100. I'm goig to use Ultrafin liquid (not Ultrafin Plus) to develop it - dillution 1+20. Any idea what should be development time? Ilford says it is 11 min. (20°C/68°F) at ISO 125 and 14 min. at ISO 200, so what about ISO 100? Will 10 min. be fine, how do you think?

 

[Rick A]

http://www.digitaltruth.com/devchart.php?Film=FP4&Developer=Ultrafin&mdc=Search&TempUnits=C

 

[MrBrowning]

I'd think you'd be fine at 11 minutes.

 

[dawid]

@ Rick A: Well, I have checked digitaltruth before, but it doesn't show time for Ultrafin and FP4 at ISO 100... Thanks anyway.

@MrBrowning: I'll try 11 min. but 19°C/66°F. I know the difference between ISO 100 and 125 is slight but still... Sometimes it's the small things that make a big difference.

 

[MrBrowning]

@ Rick A: Well, I have checked digitaltruth before, but it doesn't show time for Ultrafin and FP4 at ISO 100... Thanks anyway.

@MrBrowning: I'll try 11 min. but 19°C/66°F. I know the difference between ISO 100 and 125 is slight but still... Sometimes it's the small things that make a big difference.

Even if you went to 10 minutes it should be fine and yes it is the little things. But that's only a 1/4 stop. I just ran 6 sheets of Foma 100 at 25. I developed it for my N-1 and it looks to be fine (I haven't printed it yet). FWIW I forgot to change the film speed on the meter before using it.

 

[Thomas Bertilsson]

@ Rick A: Well, I have checked digitaltruth before, but it doesn't show time for Ultrafin and FP4 at ISO 100... Thanks anyway.

@MrBrowning: I'll try 11 min. but 19°C/66°F. I know the difference between ISO 100 and 125 is slight but still... Sometimes it's the small things that make a big difference.

Have you looked at Tetenal's web site?

http://www.tetenal.com/imaging_shop/images/00001805.pdf

It appears that you need to decide first what kind of gamma you want, and then pick a developing time.

If you shoot FP4+ at 100 instead of 125, it will not make any difference in your negatives. Develop as normal. The difference is small enough that it will vanish within the margin of error.

 

[dawid]

@MrBrowning: I did exactly same thing, I forgot to change ISO...

@Thomas Bertilsso: I have looked at Tetenal's website, however I guess I'll stick to what Ilford gives.

 

[RobC]

Tetenal give two gamma values, .55(8 mins) and .7(18 mins). ISO film speed gamma is approx 0.62 so a time somewhere between the two would be correct. 11 minutes seems as good a starting time as any to detrmine if that gives you the contrast want.