UV camera project build question

BobORama wrote:

Perhaps I am mis-reading your post, but you don't want an internal filter. You do want a IR-VIS-UV pass broadband window, e.g. quartz with broadband AR coatings, that make up the optical path length of having the IR cut filter. Without this, lenses will not focus to infinity and / or you will have ghosting. Then you use an external UV short pass filter, or whatever filters you want. . The camera will also work for IR and general multi-spectral work. t.

I and some of our researchers here, have had good experiences with this eBay seller, including his converted cameras and filters. I have one of their larger UV cut filters It is great and rejects IR and VIS > 250:1.

http://www.ebay.com/usr/image-laboratory

Interesting my searches hadn't turned them up... Now I've ordered a couple more filters - Properly mounted BG40 & UG11 not cheap but hopefully the AR coatings will make the postage/import duties worthwhile, and the mountings will be more convenient than my current bare 25mm discs!

As for a fun DIY project, if you want something to play with, web cams are a great way to do this, as pretty much they are a bare sensor, so easily modified. And given how bad some people's UV photography turns out, you may actually be better off.

Also, be in the lookout for old spectrophotometers ( the IR-VIS-UV type or anything with UV. Some of them will have a lens assemblies, and this will necessarily pass UV. Small UV lenses ( suitable for the webcam ) can be had from optics places. Some times colleges / universities chem and bio department have heaps of this stuff hidden away and a polite request will liberate one of the broken ones.

All the spectrometers here I've used (10 different models IIRC, including UV/Vis, IR, atomic & Fluorescence) use mirrors to direct/focus the light. The focal length of lenses varies with wavelength so would not be very good.

There might still be an interesting source of components to play with potentially having half silvered mirrors, lasers, diffraction gratings, light sources... Unfortunately by the time works finished with them the remaining life hasn't made it worthwhile trying to sort out portable power supplies, which only leaves mirrors & gratings. I might try stripping out current UV when it gets replaced, but I'd rather keep it running as long as possible - the proposed replacement will not take lenses or filters in the sample compartment!