Fascinating... and frightening. I hope that all manufacturers won't make an habit of adding anti-UV coatings to their procuct.
Sandy mentionned that most film tested between 0.15 and 0.30 As most of us don't have the quipement to measure UV transmitivity, would it be possible to post the results for the films taht have been tested? Information about classic films like FP4+ HP5+ and Tri-X would certainly be appreciated by a lot of people here.
Here is probably a dense question but what benefit is there to putting an anti UV coating on in the first place?
Philippe, I only use 400 Tmy and FP4 so my measurement for b+f are .21 for FP4 and .19 for 400 TMY. Note though that for an SBR of 5 or what would be N+2 in zone system the b+f jumps to .30 and .25 respectively.
Philippe,
The b+f UV readings vary a lot with films, with the developer, and with the CI to which the film is developed. For example, with FP4+ the b+f UV reading is only about 0.08 for a CI of 0.55, but it jumps to about 0.25 for a CI of 0.85. TMAX 400, TMAX 400, and most of the Hungarian films (BPF, JandC, Forte, etc.) will have a UV b+f of over 0.15 with a CI of 0.55, which will increase to over 0.50 for a CI of 0.85. Ilford HP5+ has slightly lower b+f UV readings than the Kodak high speed films.
The above is with develoment in Pyrocat-HD, a staining developer. Other staining developers will give different results.
For discussion and information about carbon transfer please visit the carbon group at groups.io
[url]https://groups.io/g/carbon
Jorge Sandy: thank you for uncovering this little known piece of lore. I suppose that the data would be pretty different with a non-staining developer, especially with the Hungarian films which are known to stain well because of their thick emulsion. My current choice (HP5+ in HC-110 dil B) is probably pretty UV friendly, which is exactly what I needed to know.
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