reciprocity polaroid 55 p/n

[buggy]

I'm beginning to shoot the polaroid 55 p/n through a pinhole and wondered if anyone had experience with reciprocity correction? I've searched the forums and found some info on other films but not polaroid 55p/n. Thanks!

 

[gwatson]

Not sure if these times are long enough for your use, but they are taken from Steve Simmons book and I have found them to be pretty accurate. (The reciprocity info on the polaroid datasheets I've seen is woeful.)
Metered (secs):16 = 36
24 = 65
32 = 90
45 = 140
60 = 204
90 = 350
120 = 504
Hope this helps. Geoff

 

[buggy]

Thanks Geoff.

 

[Will S]

Is that at ISO 40 or 25?

Thanks,

Will

 

[gwatson]

Will, I think I'm misunderstanding your question. If you are referring to dev compensation changes, then he (and I) suggest you don't. If you're referring to where he rates the film, I don't know. Personally, I think 25 is a little too slow and would suggest 40 as a starting point for the neg. If you're not referring to either, can you expand? Cheers.

Geoff

 

[buggy]

I personally rate the negative at 25, and the few times I need a print, I rate at 50. I always develop for 1 minute irregardless of shooting for a print or negative. As long as you set the correct ISO on your meter you will get the correct shutter for that ISO. I always meter at f22 and multiply by 49 to get the correct shutter speed for a f154 pinhole. If I'm correct f154 is 5.5 stops from f22. Hope that helps...