I own a Quantum Qflash and they have just come out with a UV/IR head for their flash units.
I plan to purchase it to use with IR photography, BUT...........
I'm intrigued with UV photography now. I can't seem to find any posts on APUG regarding UV photography other than using UV light for other processes, i.e. palladium prints and the like.
Does anyone have any knowledge on this subject and/or resources that I might be able to check out. I've seen a few websites, but I'd still like to here from you guys on here.
I've read about a Wratten 18a filter used to block out all light other than UV and some IR, but guess what.........it's not made anymore. One of the filter makers offers a 420 (I think that's the number) that appears to be about the same thing as the 18a filter.
You guys know your sxxx.......educate me and point me in the right direct(s).
For UV photography, you will need quartz lenses (quite pricey), a hot mirror filter that cuts off both IR and visible light (again, not usually cheap for something decent), and a UV sensitive film. The only film that I can recall that had a good UV sensitivity was Kodak EIR (yes it was a false color infrared film, but it was also UV sensitive). Since that is no longer made in 35mm format, you would have to get cut down Aerochrome III 1443. I know a guy that sells fresh 120 format Aerochrome III 1443, and if you are interested, please let me know.
I have not known anyone who has done UV photography outside of the scientific community (and more importantly, outside of getting government grants). It is expensive, but I have seen some impressive shots of the UV markings on flowers with Kodak EIR. Best of luck!
Steve, B+W produce (or at least did) the 403 which is used for UV photography. Exposure factor 8x-20x.
Do you know if any of that photography is online?
Originally Posted by Alexander Ghaffari
I've done a fair amount of playing around with UV photography. In my opinion, the best overall summary and examples of it are on Bjoern Roerslett's site.
You do not need pricey optics or special film to do UV photography. I typically use the apo Nikkor process lenses, which have almost exactly the same focus in the near UV (350-400 nm) as the visible. They have quite good UV transmission, as do many of the EL lenses (which, however, are not apo but are very inexpensive).
I have used a 403 filter, it's fine. I also have a 325 but haven't played with it yet; it's set aside for a winter solar project.
For film, I have used mostly polaroid type 55 and 665, because it allows me to check exposure quickly. Actually there is almost no exposure compensation when you use old, traditional b&w films with a 403 filter and the lenses that I mentioned.
Bottom line is: just look at the filter cutoff, the film sensitivity curve, and the glass cutoff as a function of wavelength and all will be clear. Obviously the UV intensity you record will be a convolution of those three things.
Yeah, Bjoern has some good stuff, and he is really smart and handy with photographic equipment. For anything worth your time, you really do need quartz optics (to get UV images within, say, the deeper parts of Aerochrome III 1443's UV sensitivitiy). I have done a lot of spectrophotometric work and you can fudge everything with plastics, borosilicates, or what have you, but the best results are with quartz. Of course, I had to be very picky with my work, but I do not want you spending a lot of time and money, only to cut one corner, and end up with sub par results. With Aerochrome III 1443, you can get very good UV sensitivity around 300 to 320 nm (basically the UVB range)...anything much less than that is going to be in the UVC range. If you are photographing high amounts of UVC reflectance from anything not the sun (that would be a UVC emitter, I know, and I know how the atmosphere filters much out, but that is beside the point), you better be wearing UVC goggles and have every centimeter of you skin covered if you do not want cataracts, skin burns, and possible skin cancer down the road. Anyone who has worked with germicidal lamps knows what I am talking about. Anyway, have fun with UV photography! I find it a bit harder to work with than IR photography, unless you are doing pinhole work (in which case IR photography is terrible).
I have done a little UV photography using Ilford HP4 and a UG 1 filter from Ealing Optical.
For landcapes the filter acts as a strong neutral density but the overall result does not look very different from normal except more hazy as you might expect.
A tungsten lamp using this filter on the lens enabled me to take a self portrait showing 'invisible' skin blotches and blemishes (quite scary). This is used in forensic photography to detect bruises after they appear to have healed.
The filter is quite expensive (it cost £50-60) and was used for a forensic project. I have never tried it with colour film.
I agree about the website mentioned above. Very good.