Wista bellows IR-proof?

[victorknotzel]

Does anyone know if the standard + wide angle bellows for the Wista 45 VX (the metal one) are good for IR-film?
The good sunny weather is slowly arriving here!

[ataim]

On my Wista M450 they are.

[RichardRitter]

Yes, No, May be. I would test the bellows.
Why.
There are many different types of bellows material to make bellow from and your camera many have a different type of material on it from some one else on the forums that has the same camera and said that it is ok. You go off and do a very important photo shoot only to find out that your camera bellows is not IR safe.
When in doubt it is best to test your own equipment and not relie on the advise by others. I have read a lot of wrong advise on this and other forums.

[vinny]

What Richard said. Go out on a sunny day, Put a holder in, pull the slide half way with lens cap on or blank lens board, wait a minute or two. Process that sheet. It'll be quite obvious if there is an issue with this method and you don't introduce other variables that could throw off your results.

[victorknotzel]

Hmm, ok. So wouldn't it be possible to take a photo through the bellows with my digicam where i have removed the IR-blocking filter? I'd hate to waste my sheets of High speed infrared :D

[Jac@stafford.net]

Be sure you have IR proof film holders, too.

[victorknotzel]

Be sure you have IR proof film holders, too.
Didn't think about the holders at all, thanks for reminding me.
The bellows are indeed IR-proof, my IR camera saw nothing. The packard shutter for my petzval however, is nowhere near IR proof.

[B.S.Kumar]

Richard and Vinny are certainly right that you should test your own camera, because the bellows may not be the original one. I have a fair amount of experience with a variety of Wista technical cameras - 45D, 45N, VX and RF, with normal and both kinds of wide angle bellows. I have used these cameras with a Betterlight scanning back, which needs an IR cutoff filter for proper color response. All the cameras that I used were IR proof. YMMV.

Kumar

[Jac@stafford.net]

Didn't think about the holders at all, thanks for reminding me

You are welcome, of course. In my experience the later holders with expressions on the top of the slides are more IR safe, however in the days of Kodak HSIE they still had to be protected from direct sunlight. (I miss that film. I still have lots of it in deep freeze but have become convinced it is no longer good.)

I used IR not for aesthetic concerns, but to cut through haze, largely to show what we cannot see in everyday life.

[genotypewriter]

Didn't think about the holders at all, thanks for reminding me.
The bellows are indeed IR-proof, my IR camera saw nothing. The packard shutter for my petzval however, is nowhere near IR proof.
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

[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 :cool: 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