Delta 100 vs TMX technical differences

[Pere Casals]

Pere:

In the original tech sheets Kodak indicated the TMax emulsions were designed to have slightly less blue sensitivity than other panchromatic films, in order to more closely approximate the sensitivity of the eye. This has nothing to do with the UV attenuating dyes which were/are on the film base.

Thanks for that information. So if the UV blocking is at the base then it has not that effect at all. Still I don't understand why using a base with UV blocking additives...

So lower blue sensitivity may/should be related to the sensitizing dyes and possible staining dyes potentially used for performance enhacements in dye sensitization.

Still including non sensitizing dyes in emulsion/supercoating to tame blue it could be a technical choice, perhaps, just speculating...

[djdister]

Thanks for that information. So if the UV blocking is at the base then it has not that effect at all. Still I don't understand why using a base with UV blocking additives...

Since UV radiation has a shorter wavelength than visible light, UV rays would pass through the emulsion layers and continue to "scatter" around between base and emulsion if they are not absorbed or otherwise attenuated by dyes in the base layer. As a related example for cutting down on UV rays hitting the film, some folks use a UV cut filter in front of the lens...

[Pere Casals]

Since UV radiation has a shorter wavelength than visible light, UV rays would pass through the emulsion layers and continue to "scatter" around between base and emulsion if they are not absorbed or otherwise attenuated by dyes in the base layer. As a related example for cutting down on UV rays hitting the film, some folks use a UV cut filter in front of the lens...

Yes... but also there is the anti-halation layer, so photons that have arrived to the base won't scatter there and will go to the anti-halation layer to be absorbed there. The UV absorbing film base would be a good idea if anti-halation layer reflects UV, just speculating, perhaps used anti-halation layer was not black enough for UV...

[Michael R]

The UV dyes apparently had to do with reducing static-related exposure from the back of the film.

[Pere Casals]

The UV dyes apparently had to do with reducing static-related exposure from the back of the film.

Hello Michael, so (I understand) as anti-halation layer is opaque... light comming from the back has been reflected in the interface base/anti-halation layer. The UV absortion of the base may remove that problem for UV... I guess...