Will a LED UV light source damage film negatives (or acrylique picture frame)?

[mzjo]

As the title says. I am going to have a go at cyanotype prints, on a very small scale, just for the fun and to see where it leads. UV sunlight being a bit scarce at the moment I am thinking of experimenting with a UV source designed for gluing (or something similar) false fingernails. The source is there, free and doing nothing except occupy shelf space so why not! It will take 6x9 negs (just). I don't know how well it will expose a cyanotype print, it works or it doesn't, that's not a world-ending problem. The question is can I use a UV light source with 120 film negatives or is the film likely to be damaged by the UV rays? If I use a clip type acrylic picture frame as a press is the acylic likely to get damaged as well (in the short term, say a dozen prints - I know that long term damage to the acylic is very likely). The source is marked lamp LED 6W, it runs off a 5v power source and just takes 6x9cm (9x12 would have been nice but if I follow up on the process it will undoubtedly mean building a slightly bigger UV source and probably getting a clubmate with a suitable printer to print me some decent negatives. My ambitions don't run to bigger than 5x4 or perhaps half-plate).

This is perhaps a bit of an idiot question but I would rather not make an obvious error (or at least a known error) right at the start.

Cheers Jo

 

[koraks]

No, certainly not for exposures of minutes up to an hour or so.

 

[nmp]

If I use a clip type acrylic picture frame as a press is the acylic likely to get damaged as well (in the short term, say a dozen prints - I know that long term damage to the acylic is very likely).

Cheers Jo

Why not use glass frame instead? You will get a better contact and higher UV throughput.

:Niranjan.

 

[Petrochemist]

Why not use glass frame instead? You will get a better contact and higher UV throughput.

:Niranjan.

Undoped acrylic actually has a better UV transmission than glass. Though most acrylic is doped to reduce UV damage which does away with that advantage.
For printing the extra weight of glass can be an advantage, helping keep the negative flat, so it's not worth sourcing the undoped plastic..

UV sources for curing nails will be long wavelength UV, probably 395nm only just in the UV. If these degrade negatives etc at all it won't be faster than sunlight for a similar exposure.

I've used UV LED strips for cyanotypes which makes printing in UK weather far more practical

 

[koraks]

UV sources for curing nails will be long wavelength UV, probably 395nm only just in the UV.

Not so sure about this anymore; 365nm has become quite popular for resin curing applications. I'd not be surprised if the nail curing systems have moved to 365nm as well lately.

Btw I would not recommend the nail curing systems as such since they're generally designed to cover a relatively small area. Contact printing for photography generally involves somewhat or much bigger surfaces and more power.

I presently mostly use a single 365nm 100W COB LED with a 60-degree lens for 4x5" contact prints.