I posted this in one of the X-Ray threads and got no feedback.
The link is below.
Any ideas and info welcome.
http://www.largeformatphotography.in...=1#post1225996
I posted this in one of the X-Ray threads and got no feedback.
The link is below.
Any ideas and info welcome.
http://www.largeformatphotography.in...=1#post1225996
Tin Can
If you're looking for encouragement, go for it? I would try it, if I had the film. Why not?
I just did a quick google search for B&W UV images and the results weren't pretty. I would avoid doing portraits, unless you want to make people look sickly and dirty. I didn't see any landscapes or architectural, in my quick search. Just sickly people and odd flowers.
Yes, one of my links showed that.
Not everybody desires conventional worldview, is my answer.
I am seeking more technical reason why it may not work at all. If an UV/IR machine contact copy takes 10 seconds, perhaps a sunlight only exposure in camera with small stop may takes hours. Hard to estimate the speed of this unknown, except as you suggest empirical testing.
I may just try it, but first a little more research, which is what this thread is about.
Thanks Jody!
Tin Can
I'll just keep talking to myself.
If I used this film would I need an IR filter?
From, https://www.schneideroptics.com/pdfs...dOfFilters.pdf
I got this info.
Tin Can
Maybe I miss something but where the IR part come from ? As I read this film is sensitive only to UV.
IR is on the other end of the spectrum so I assume it has even less sensitivity.
An IR filter will cut the UV and the visible.
If you read the same page I did (www.ultravioletphotography.com), there was a big discussion of filtration, but that was to use a full-spectrum sensor for UV photography. Since you have UV-only sensitive film, you shouldn't need any filtration at all. What you really need is a spectral sensitivity curve for the film, that will guide you on subjects and compensating exposure for different lighting situations. If you can't find the curve, just take a photo of a color chart in broad daylight, to see if the film is sensitive into the visible light range.
I doubt if the film will be usable in any standard artificial lighting, as everything that emits UV has coatings to block it, to reduce the health hazards for humans.
However, you could get a couple of old tanning lamps if you wanted to experiment. I have an old 500W one upstairs that I planned on using for alt processes, that was banned because it causes cancer (it has the correct UV band emissions that I need for my hybrid biochemical process I'm working on). But more modern UV lamps are safer. They're cheap and easy to find, most people have clued in that they're not really safe to use.
Yep we used those stupid tanning lights in Minnesota in the 50's. My father had skin cancer. We also had the shoe store fluoroscopes that ruined my feet...
I would think the film may work in sunlight?
http://commons.wikimedia.org/wiki/Fi...r_Spectrum.png
Tin Can
Yes, it will work in daylight, but you'll have a heck of a time calculating exposure. UV present in daylight depends on thickness of the ozone layer, amount of moisture in the air, time of day (angle of sun relative to you changes the distance sunlight travels through the atmosphere, which filters UV). Etc. Again, this is assuming the film is sensitive to UV only, and I'll assume it's sensitive to near-UV, that is it works with standard 'black light' fluorescent sources. Near-UV is abundant in natural sunlight, it's the shorter wavelengths that are most filtered through the ozone layer (and these are the ones that cause cancer). You could simply monitor the local weather station for their 'UV index' during the summer, that would be a rough guide.
It's possible the film was designed to work with short-wavelength sources of light such as the anti-bacterial lights used in hospitals, food prep areas, etc. But I think that's unlikely. An old-style UV tanning light puts out a full range of UV, because the short wavelengths tan you a lot faster (besides causing cancer and damaging your eyes). The one I have came with a primitive light stand that's ideal for studio lighting of tabletop still lifes.
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