Anyone make any progress with this?
Anyone make any progress with this?
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
FR4 and G10 glass reinforced epoxy are pretty common materials due to their use in PCB manufacture (I believe they are the same except that FR4 is fire retardant). It may be a little harder to get 0.9mm = 0.035" specifically, but I'm sure someone makes it. It also should not be super expensive.
Here's a supplier that advertises black FR4/G10 in 0.031" thickness in sheets up to 36x48", which costs $42 (probably make about 15-16 darkslides): http://www.americanepoxy.com/g10fr4sheet_Black.html
Here's a supplier that only advertises thicknesses down to 0.06", but you could always call and ask if they can get thinner sheets: https://www.eplastics.com/sheets/micarta/g10-fr4
I have no experience with these suppliers, I just found them by searching for black FR4.
FR4 is not terribly hard to cut with a fine toothed saw, and clean up with sandpaper, so it would be possible for a hobby builder to order a sheet and try to make some darkslides at home. Some of these suppliers offer cutting/machining services, so if you can make a mechanical drawing, you might be able to get darkslides manufactured (if you can forgo handles).
Is metal not a reasonable substitute? I recently replaced a polaroid 405 holder dark-slide with one fashioned out of a steel sheet at it seems to work well.
Tin Can
I'd recommend a product called Brillianize to stop static electricity on your finished dark slides. Just spray it on and wipe off with a microfiber cloth. There was not long ago another photographer who was experiencing static when working in cold, dry air in Death Valley. I suggested this product and got a report that it indeed resolved the issue. It's available from several sources:
https://www.framedestination.com/fra...er-polish.html
https://www.tapplastics.com/product/...rillianize/112
I was the original poster in another thread who wrote of the problems I had with Garolite xx.
I had some left over aluminum pieces that were the right thickness so I made those up into dark slides. The problem with a material that is that stiff is that it is prone to leaking light between the light trap and dark slide if there is any pressure on the aluminum. It's too stiff. It should be noted size matters, on 4x5 I doubt there would be a problem but as you increase the dimension going across the light trap there is a greater chance of deflection causing a leak.
This was my experience with the holders I made. It's quite probably my method for constructing the light trap that is the weak link. I didn't take the time to do it the way Fidelity constructed the traps in my 5x7 holders. There they used two different types of metal at two different thicknesses to perform two distinct functions. The "fingers" in the brass piece would compensate for deflection in the dark slide material. Since I didn't follow this method I ended up with problems using aluminum.
As a side note, I'm in the process of helping a friend construct two wet-plate cameras that are 24" x 24". We are using Garolite XX for the dark slides. I doubt ISO 2 will be sensitive enough to pick up any radiation for the duration that it will be exposed...
I have nothing to add, but a question: what darkslide material does the Chamonix holders use? I've seen it described as "carbon", but I don't own such holders, so I can't make any comment on its qualities.
Well, one can buy all sorts of carbon fiber sheet. Carbon as a pigment is pretty good at blocking light.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
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