Ilford FP4+ at 400 asa

[arigram]

I accidentally exposed a roll of 120 llford FP4+ at 400 asa. It was the first roll I put through my new Rolleiflex 2.8FX and had forgotten its iso dial for the meter.
I have Ilfosol-S, D-76 and Rodinal. I would need to mix the D-76 as I only have it in powder form.
Any suggestions on times?
Can I adjust the time of FP4+ in Ilfosol-S with an algorithm of sorts?

 

[selenium96]

The Massive Development Chart on DigitalTruth.com lists this for Ilfosol S for 35mm but the 120 and sheet film columns are blank:

FP4+ Ilfosol S 1+9 400 13 min 20C

 

[Steve Smith]

Here's a coincidence. We had a very similar thread this morning: (there was a url link here which no longer exists)

I would increase the time by 25% for each stop so in this case, 1.25 x 1.25 = about 1.5 x the normal time.



Steve.