JandC Classic 100 Reciprocity

[Will S]

Anyone know the reciprocity exposure compensation needed for JandC Classic 100? It seems high from what I'm seeing on my negs (4x5) at times of 1-4 seconds.

Thanks,

Will

 

[Andy Tymon]

Hi Will,
I find that I have to rate it at 40 iso to get the zone iii values I prefer, thats with rodinal 1 to 50 with pyrocat hd i get an iso 50. As to reciprocity I always found just doubling the length of time in the 1 to 20 second range always worked for me. I don't know what type of pictures you are making,when I do still life i always have to remember to factor in bellows extention, I tend to overlook it in the heat of the picture making experience : ).

 

[Will S]

That's what I'm seeing too. 1 sec = 2 sec. 2 sec = 4 sec. Seems high, but if it works...

Thanks,

Will

 

[Donald Qualls]

Seems to me J&C has suggested, over on the Sponsors' Forum, that the reciprocity table for APX 100 would work for Pro 100 (as will the developing starting times).