4x5 Vacuum Film Holder "RW Institute"

[konakoa]

I wonder if anyone here has ever seen one of these. It's a Fidelity film holder, but modified for vacuum by a company called the "RW Institute of Color and Photography". I have not been able to find a thing anywhere about these.


They are pretty dang neat. They do pull film down flat, and I've been using them for astrophtography. These modified film holders are a whole lot lighter and simpler on and off the camera than the Schneider Hi-End back.


Anyone know anything about this RW system?

 

[Axelwik]

I guess it would be useful for a really fast lens (or shooting open aperture) such as, as you mentioned astrophotography.

Is it double-sided?

 

[John Patrick Garriga]

I'm a little confused as to why you'd want this. Seems like more work when your film should be flat in the holder anyways, but I'm sure I'm just a dummy.

 

[abruzzi]

Should be, but depending on orientation and the film, it could bow in the center. I’d think 8x10 and larger is much more likely to have the issue.

 

[konakoa]

Axel, they’re single sided. One of the sides of the holder was used to create the vacuum modification.

John, they do two things for me; they do hold the film very flat so I can make the most of using my lenses wide open. Also equally important they keep the film absolutely stationary as well, the film won’t slide or shift at all during long fifteen minute or more exposures.

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The holders are Fidelity Elite models, so they're kinda new-ish. I was hoping somebody had seen these before as I was curious about the company that made them and when.

 

[warpath]

Hmm, curious... is it modified/constructed in a way where if certain parts of the fidelity elite breaks, you can replace with another fidelity elite holder? Thanks

 

[Philippe-Georges]

What about dust? I might be wrong, but doesn't 'sucks' it in when taking out the dark slide for exposure as the film - backplate combination doesn't looks that airtight, how could it be?

 

[konakoa]

The flap at the bottom of the holder could be replaced, the rest is all molded factory plastic from Fidelity or the custom modifications, likely glued in there in a way they could not be taken out. They're too nice, too unique to tear it apart to see how it was built.

The vacuum isn't that strong. It's a very mild, gentle suction. You can barely feel it on a fingertip. But it is enough that when the film is in the holder, you can't pull it out with the pump on. My very similar homemade versions of these holders and hundreds of exposures made with those I've never, ever had a problem in decades of use with dust created from the vacuum. This 'RW' is just fancier and much improved over my garage tinkering.

 

[DREW WILEY]

Astro work requires very long exposures and an unshifting precisely flat film plane. I've never seen one of these, but have made my own 8X10 ones - not for telescope usage, but analogous scenarios where I don't want any change in film position or flatness whatsoever. No dust is drawn in because the vacuum draw is applied to the back of the film through a series of small drilled holes (about 1/16th inch diameter).
You turn it into a one-sheet holder. On the opposite side you glue in little struts of the right thickness to prevent the median plate where the film sits from flexing. Then you put a little metal air tube into the edge of the back, and then seal off that entire back side by cementing its dark slide shut with black silicone RTV sealant. A relatively simple project.

 

[Philippe-Georges]

 

[DREW WILEY]

Sinar also made an expensive press-fit back for 4x5 film. I suspect simple vac backs work better than either. And then there's the adhesive filmholder option too.

 

[John Wiegerink]

Sinar also made an expensive press-fit back for 4x5 film. I suspect simple vac backs work better than either. And then there's the adhesive filmholder option too.

Yes, I have one 8X10 adhesive holder. Can't remember where I got the darn thing, but I think it was when I was doing camera shows in the mid-80's and 90's.