Wista bellows IR-proof?

[victorknotzel]

I do a lot of IR/full spectrum and UV photography using digital with several modified cameras and I really can't see how something like a film holder can upset things for IR. How much worse would things be for normal photography if film holders were made of a white material? I don't think it's any different to that. Once I get back home I'm going to check if any of my holders show up lighter under IR.

This would apply even less for shutters because, how long does it take between pulling the dark slide and putting it back in?

G

I'm afraid it might fog something up, because this thing really shines bright like a sun. It might not be a problem with an R72 on the lens, but still. I have bought a newer one, maybe it's more light tight. The holders seem to be perfectly fine

[Jac@stafford.net]

I do a lot of IR/full spectrum and UV photography using digital with several modified cameras and I really can't see how something like a film holder can upset things for IR.

The issue is IR transparency of the holder and slide. Generally, it is more of a problem with super fast, highly sensitive IR film, of which we have none today for large format. However, leaving a film holder in the bright sun will show fogging if there is any to be found.

How much worse would things be for normal photography if film holders were made of a white material?

Interesting observation. B&W IR film sees some fabrics, in particular nylon, as brilliant white, but most carbon-colored (black) plastics are dark - IR absorbing.

[genotypewriter]

I'm afraid it might fog something up, because this thing really shines bright like a sun. It might not be a problem with an R72 on the lens, but still. I have bought a newer one, maybe it's more light tight.

Unless the shutter creates a bright red reflection, it's not going to fog IR film any more than it fogs normal film.

The issue is IR transparency of the holder and slide. Generally, it is more of a problem with super fast, highly sensitive IR film, of which we have none today for large format.

Things don't suddenly become transparent in IR photography unless they already have some degree of transparency At the end of the day it's the same question as whether white "dark" slides would fog normal film.

Also the response of most IR film drops off greatly before getting to even 900nm... I can't see how they can be sensitive to long wavelengths ~8000nm that penetrate thin surfaces.

G