August 07, 2006

• Hope you don't mind: I popped a "Curious, George" in there and stuck the details inside. Sorry I have no tips for you.
• I'm not an expert an photographing urine, but maybe you could use a small non-black light at the same time? I would expect that the urine in restroom still glows when lightly lit from another source (while still using a black light), while lightly lighting area by the front door with another source (while still using the black light) would reveal detail around that area while displaying no urine streaks. Of course, if urine is not showing up, I don't know what other detail you need in the photograph. I'm not positive cat pee has the same black light properties that human pee has. They have a different diet, and a different digestive process (hence the need for a different diet). Their waste may not contain the same chemical that glows under a black light, or whatever it is that causes glowing. Maybe you should verify that cat pee would show under black light conditions. I don't know if checking a litter box with a black light would be enough, because the litter could already have black light properties, or the reaction of cat pee with kitty litter could produce a chemical by-product that has black light properties. Again though, why would you need more details than "no pee here"?
• CSI Filter?
• Though I have never watched the show, I googled CSI and Blacklight, and a very significant number of hits came back that included Cat Urine, though I did not include that in the search. This link may actually provide some information, it doesn't mean anything to me.
• Talk to this guy: he shoots scorpions in UV with his digital camera....
• Interesting. I've never tried shooting under black light, and cannot verify the whole black light/urine bit. But if the issue is that you're just getting a purple blur... Do you have a tripod or something you could use to stabilize your camera? It's probably a dim light, or it's dim in the white light spectrum. Anything you can do to hold the camera still, adjust manual settings to a longer exposure, etc. might be helpful.
• The photos themselves aren't blurring, they just aren't showing the illuminated, greenish. . . stuff. It just looks like a regular photograph only with purple light. As far as cat urine vs. human urine, I found out about the blacklight thing over at Me-Fi and tested it out last night on both human and cat; human was definitly more vivid, cat urine still stood out but not as brightly. Diet or careful aim on the cat's part? Who knows. . . I'm checking out the info on the CSI link, pretty interesting. Perhaps going with a slower shutter speed will do the trick, although right now it's pretty slowish.
• What kind of camera do you have, and what settings are you using on it when you take your pictures? I'm not up on F-stops or all of that (though I'm certain that there are smart camera monkeys out there!), but my camera has some built-in settings for shooting in dim light. (I'm not trying to advertise for my camera, here, but coming from what little experience I have) I have a little Sony Cybershot (5.1 megapixels, 3x zoom... if that helps) that has two dim light settings built in. They're both on the dial on the top. One is a little moon shape, meant to take pictures in full dark outside, and the other is a little candle meant to take pictures inside by dim (candle) light. Both are cool because they preserve the colors of the original scene. (Oh -- there's also settings for taking portraits at night, which have the moon and candle pictures with little people in front of them.) If your camera has anything like these, try playing with them and seeing if they do any better. My camera also has a neat feature that helps it focus well in dim light. It shoots a little orange light at the scene. The orange light doesn't show up in the picture, but it helps the camera focus because digital cameras use contrasts in light (which are hard to come by in dark scenes) to create focus. If your camera doesn't have this, try shooting a little pen light or laser beam at the scene to help with focus. (You can always explain what the lights are for if they show up in the pics.) Maybe if you're focused better you'll get more detail in the picture? I hope these ideas help at least a little. I'll also email a friend who's a good amateur photographer and ask her what she thinks.
• Ooh, sorry I killed the thread! Anyway, I asked my friend and she said she'd think about what to do, and also asked what kind of camera you have.
• I have a Nikon D70 that has the light sensitivity set to flourescent 'cause that's the kind of light I'm using. F stop is 3.5 and shutter speed is 1.6 seconds so there's no problem drinking in the light, the kicker is getting the scene that I'm seeing with the naked eye to appear on digital film.
• Nice camera. Ah, fluorescent? That'd be the white balance setting for white fluorescent light. So... prolly not the right setting. But then you'd have already tried the automatic one. So the stains are much lower in intensity than the surrounding purple light? Maybe there's some kind of filter necessary for this type of photography. Do you have a UV filter on the front of the camera? I always leave one on mine, that might block some of it. Um. I'm stumped, sorry.
• My friend also suggested making sure that your lens doesn't have a UV filter, which might block out what you're trying to see. Also, she said she'd ask a photography message board she's on to see if anyone had any ideas. I'll get back to you when she gets back to me. Also, I feel my suggestions above were horrible naive, so please forgive. I don't know much about it, and probably should have just asked my friend instead of offering any advice. *wince*
• Bah! horribly, of course
• The UV filter! This is one of those 'ah-ha' moments. I'm at work now but as soon as it gets dark tonight I'm going to try shooting again with the UV filter removed. Gee I'm glad I have Monkeyfilter. . .
• My friend got back to me with more info on how to do the UV filter, including this page about taking UV pictures. She also wondered if it was hard to take UV pictures with a regular digital camera, because she read this review of a camera specially designed for it.
• Oh, and apparently there's a filter you can buy that will only pick up UV -- basically the opposite of your other filter :)