Hi Michael:
OK, thank you. Good luck with your project.
Barry Young
Hi Michael:
OK, thank you. Good luck with your project.
Barry Young
It's been a while since I've added to this post. I did some more experimenting with the light baffle (where the dark slide slides in /out). Thanks to Erik Larsen, I found some finger springs at Omega Shielding that I'm trying out. Here is the link:
http://www.omegashielding.com/099-720-NT.php
My first try was to glue blackout cloth, painted flat black on one side, down on both sides of the springs. That still let some light through, so I then pried up the side of the fabric closest to the film, following a suggestion by Erik to glue the fabric down only on the edge closest to the insertion point. This seems to work well, and the opening appears to be light-tight when the dark slide is in and out.
Next step is to complete the assembly and try it out!
Last edited by Michael Roberts; 25-Aug-2019 at 09:31.
I have just picked up on this thread rather late. You may have considered this already but I have used black velvet ribbon (which can purchased in a wide variety of widths), to renew light traps on cameras. David Odess has expressed a preference for this when restoring light traps on Hasselblad backs on his website. Worth a try if your experiments with felt are proving troublesome
Hi Michael, keep up the good work. If you find you are getting leaks still, Steve's suggestion is a good one. I have used black moleskin that is similar to velvet but is adhesive backed. It is used for sealing auto windows. You can get it from 1/4 inch to 2 inches wide I believe. Good luck with the project.
regards
erik
Thanks Steve. Ribbon suggests to me a velvet/nylon combination. I'll look for David's website to see if he provides more details and will check my local fabric stores.
Given Paul's recent thread on his 14x17 film holder project (https://www.largeformatphotography.i...build-question , I went searching for this old thread. Finally found it (apparently search terms are case-sensitive). It was one of the old posts where the attached photos were lost in a server migration. So I searched my hard drives and found the old photos. Since the mods now allow perpetual editing, I was able to restore the old attached photos to the appropriate posts (more or less).
Believe it or not, I am still working on these holders. Or to be more accurate, I put them away for about eight years before resuming work on them this past year (one of many projects I quit my day job to have time to get back to a couple of years ago).
I think I solved the baffle problem (with Erik Larsen's help). I'm still working on getting the 3M adhesive tape to work.
The last two times I have tested my first prototype in the field (once in February of this year and again in June of this year), the film fell out of the holder and into the camera bellows, i.e., the adhesive did not hold the film. Right now, my working hypothesis is I may have a problem with altitude changes. I live at 8,600' and extended time in the holder plus changing several thousand feet of altitude may be causing air between the adhesive and the film to expand/contract and loosen the film. If so, I need to do a better job of laying the tape down on the plenum with no wrinkles or make sure I press the film down in the morning before shooting or carry a changing back with me so I can check and press the film down when needed, as least during the experimental phase.
Still hoping to perfect these!
There is also a discussion of adhesive film holders in this thread: https://www.largeformatphotography.i...hesive-holders
Still working on applying all of Drew Wiley's suggestions and experience to this project....
What about a thin steel sheet in the middle and use magnets to tack the film down in the corners/edges? I did this in a round pinhole large format camera made of a pet food can. It held 1 to 3 sheets of 8x10. I also like the suggestion of an array of 8x10 sheets for 20x24 ULF. Tesselated ULF makes a lot of sense from a film handling perspective if you can stand the breaks in the images.
Also, in re-furbing some old holders, I noticed that some of them had internal springs that had a velvet covering and pushed a flap up into an area relieved into the opposite piece of wood. And, black gaffer's tape is light tight and I've used it to rebuild the flap hinges on old holders (plastic and wooden).
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