UV blocking film for dimroom windows?

[CreationBear]

I was reading James Reilly’s book on historical albumen processes where he mentioned that commercial sensitized paper was manufactured in rooms with yellow painted windows (or else yellow curtains.). That got me thinking: would modern UV blocking window film serve the same purpose? According to the literature, some vendors are claiming a 97% reflectivity—maybe coupled with some window sheers I might could get away with processing relatively slow emulsions without having to go the whole blackout curtain/commando cloth route?

Any thoughts?

 

[Vaughn]

Perhaps combined with a sheet of rubylith? Depending on the size of the windows, blinds to reduce the amount of filtered light coming it?

I have been slowly letting more and more light into my carbon process without ill affect. Sensitizing and air drying the sensitized tissue does need the care, though.

 

[BrianShaw]

Any thoughts?

I've casually looked into that kind of window film, but for heat reduction and fabric fading rather than photographic aspects. It might be an interesting experiment to request sample pieces and test them for UV reduction on something easy like cyanotype paper.

 

[pentaxuser]

Might it not be easier to fit heavy curtains or roller blind and coat with silver nitrate under low incandescent light ?

pentaxuser

 

[CreationBear]

Might it not be easier to fit heavy curtains or roller blind and coat with silver nitrate under low incandescent light ?

Thanks for the insights, guys—I should have mentioned there are, ah, domestic harmony issues at play as well.. As pentaxuser mentioned, I do have the ability to blackout my coating station, but development requires an incursion of my wife’s sewing room…I was looking for something with a small footprint, or at least a halo of duel use plausibility.. Brian’s experience trying to keep fabric from fading might be my in…

 

[MattKing]

a halo of duel use plausibility

Somehow I have a feeling that you actually meant to post instead: "a halo of dual use plausibility"
Thanks to Mrs. Malaprop for the PM with the heads up on this

 

[CreationBear]

Hooked on phonics…

 

[wiltw]

There is HEAT blocking, and there is OPTICAL blocking, and there is UV blocking, three factors in window films.
Important to understand which one(s) are claimed in any percentage specification claim.

 

[CreationBear]

Thank you kindly, the ones I was looking at claimed 96% UV blocking, caveat emptor of course!

 

[koraks]

The question is which wavelengths are attenuated by how much, what the sensitivity of your printing process is, and how long you want to keep the uncovered, sensitized paper around under these conditions. This is not a binary thing where it'll work or not work. It's a typical safelight scenario.

Having said that, it's exceedingly unlikely that a clear/colorless filter will be sufficient to make a room 'safe' for handling silver halide emulsions of any kind. Spectral sensitivity of bare silver halides extends a little into visible blue, which means that any filter on your windows that does not look distinctly yellow (or orange, or red) will therefore not be safe by definition. Such a filter may work fine for processes like cyanotype and other pure-UV sensitive processes provided the sensitized material is exposed only relatively briefly to the light passing through the filter, and the light isn't too rich in UV to begin with (absorption will generally be less than 100%).

From a practical viewpoint, my conclusion would be "don't bother."

 

[CreationBear]

Thank you kindly, Koraks—I’ve already (however surreptitiously) installed brackets on the windowsills in my wife’s sewing room, so fitting opaque panels during my printing sessions shouldn’t be a problem.

 

[BrianShaw]

There are a bunch of "it depends" in this very intriquing question. Can you clarify which alternative process(es) you are considering and what phase do you mean when you write in the OP, "processing".

Spec sheets are a lot more difficult to find than marketing brochures. The common UV values I've seen are 300-380nm. Many films seem to depend on density, I believe primary for heat control but perhaps UV blocking. How does Mr. CB feel about slightly darker windows? That was the deal-breaker for me...

 

[CreationBear]

Brian, I am slowly gearing up for POP processes like salt/albumen. My thought was to sensitize in “my” part of the attic that had blackout curtains, load my contact print frame, then scurry into the backyard to expose.

What I wanted to do at that point I was to have my trays set up in my wife’s territory on the other side of the house that is most convenient to a running water source in a guest bathroom. At that point, there are really two windows to contend with—the larger one on the west exposure and the smaller in the bathroom itself. It was the last one that set off this train of thought, since the UV films I was looking at are opalescent and billed as privacy screens. More efficient rinsing, and perhaps a place to evaluate toning in “natural” light would be the big draws.

At any rate, I’ll be interested in your thoughts—bit of a fool’s errand trying to navigate a space like Harry Potter’s bedroom (especially since I’m “Hagrid” sized, but I still enjoying the challenge.

 

[koraks]

fitting opaque panels during my printing sessions

That's the option I went for in my present darkroom; works a treat! The only drawback is that the panels need to be stored somewhere when not in use. Not a major issue though.

 

[Chromium VI]

Quite a timing, This week on LIDL (portugal) catalog: UV blocking film for 3€ (or soo) per 15m roll.
I never tried your idea but my current lab has a huge (5mx2m) window made of Rubylith glass, most of the time, I don't even use the red lights.

 

[CreationBear]

Very cool, I was thinking about taping film to a plexiglass sheet and using it as the insert I mentioned—rubylith sheets of sufficient size might be a bit expensive here in the States…I will check the prices.

 

[BrianShaw]

Very cool, I was thinking about taping film to a plexiglass sheet and using it as the insert I mentioned—rubylith sheets of sufficient size might be a bit expensive here in the States…I will check the prices.

Check out Rosco filter material. Very forthcoming with specifications and quite affordable through the various lighting supply companies serving the movie industry. I would just make a light wood frame and handle carefully rather than bonding to plexi, but that might be more structurally durable.

 

[CreationBear]

Much obliged, Brian—will do.