Craigo79 Posted July 13, 2021 Share Posted July 13, 2021 UV flash used in dark room on the flower to get uvivf shot.. This is cool. Will have to try it with some real flowers. Link to comment
Andrea B. Posted July 18, 2021 Share Posted July 18, 2021 Craig, I can't figure this one out?? The flower is reflecting in the water droplet? But some water droplets are hanging down and some are hanging up ??? However it it, it turned out very interestingly. Link to comment
Craigo79 Posted July 20, 2021 Author Share Posted July 20, 2021 Craig, I can't figure this one out?? The flower is reflecting in the water droplet? But some water droplets are hanging down and some are hanging up ??? However it it, it turned out very interestingly. There is a flower for the background. The uv flashes are on it. There is a bit of cotton going across over the top of water with the droplets on it. The reflection from the flower and the droplets can be seen plus the refraction of the flower in the droplets. :) That is pretty sexy.... Thank you.. Link to comment
dabateman Posted July 20, 2021 Share Posted July 20, 2021 There is a flower for the background. The uv flashes are on it. There is a bit of cotton going across over the top of water with the droplets on it. The reflection from the flower and the droplets can be seen plus the refraction of the flower in the droplets. :) Thank you.. Thank you for the description. You have some fun science going on in that image. It gives me an idea that I would most likely never do, but would be fun.Line up a bunch of different transmission resins on a string. Then photograph the UV reflectance of a flower. The various UV cut offs of the resin "lenses" on the string would give the same background flower various colors. Could be quite fun with the right subject and light. Link to comment
Craigo79 Posted July 21, 2021 Author Share Posted July 21, 2021 Thank you for the description. You have some fun science going on in that image. It gives me an idea that I would most likely never do, but would be fun.Line up a bunch of different transmission resins on a string. Then photograph the UV reflectance of a flower. The various UV cut offs of the resin "lenses" on the string would give the same background flower various colors. Could be quite fun with the right subject and light. Sounds very cool Link to comment
colinbm Posted July 21, 2021 Share Posted July 21, 2021 Dave, what are " transmission resins " please ? Link to comment
Andrea B. Posted July 21, 2021 Share Posted July 21, 2021 Craig, thanks! Suddenly it all popped into place. It's funny how sometimes we don't "see" what we are seeing. Link to comment
dabateman Posted July 21, 2021 Share Posted July 21, 2021 Dave, what are " transmission resins " please ? Colin I found this idea interesting:https://petapixel.com/2021/07/16/photographer-makes-diy-lenses-with-cake-molds-and-epoxy/ Then went down the rabit hole looking into various resins and if transmission curves existed for them. There are some that might work in UV. The idea merged here is you only need a drop on a line as a lens. Not a huge one for a large format film camera. Link to comment
Stefano Posted July 21, 2021 Share Posted July 21, 2021 If I understand, you can make resin lenses which are UV-transparent and show a flower with its natural UV false colors, and also resin lenses with a high cut-off (like 380 nm) that would probably appear lavender and make the flower appear lavender. A lens made of U-glass would appear yellow. Is that the concept? Link to comment
dabateman Posted July 21, 2021 Share Posted July 21, 2021 Yes Stefano has it. But thinking about this again, you might be able to keep it simple and just crack out your old chemistry set.Mix copper sulfate or various other common chemicals with various concentrations in water and carefully drop them on to the line to look for color differences. Maybe more art than knowledge. But I most likely wouldn't do this. This does however offer a quick test with various resins to see if they pass the full uv floral signature. Link to comment
colinbm Posted July 22, 2021 Share Posted July 22, 2021 Dave, Brilliant idea, lots of 'food for thought'. Stefano, " A lens made of U-glass would appear yellow. "I am not getting it, in my mind, this yellow ? But here is an example I just saw today too....?This is from Nabeel Ashraf from Fluorescent Minerals FaceBook post..... He says that..... "The Quartz is not fluorescent. The UV light pointed at it from the top makes it appear so." Link to comment
Stefano Posted July 22, 2021 Share Posted July 22, 2021 Stefano, " A lens made of U-glass would appear yellow. "I am not getting it, in my mind, this yellow ?If you take a UV photo of a piece of ZWB1/ZWB2/U-340 etc it will appear UV-yellow. See how the U-340 on a Convoy S2+ torch appears greenish-yellow in UV: https://www.ultravioletphotography.com/content/index.php/topic/4544-flowers-dog-and-torches/page__view__findpost__p__44962 Imagine a lens made of the same glass. Link to comment
Stefano Posted July 22, 2021 Share Posted July 22, 2021 That's a bit odd. Did you try this with sunlight/flash, broad filtration and a proper white balance? Link to comment
colinbm Posted July 22, 2021 Share Posted July 22, 2021 Obviously I am doing something wrong ?Photograph a U340 filter with sunlight behind it...? Link to comment
Stefano Posted July 22, 2021 Share Posted July 22, 2021 Another image I took (ZWB1, 3 mm thick): https://www.ultravioletphotography.com/content/index.php?app=core&module=attach§ion=attach&attach_rel_module=post&attach_id=22120Original topic: https://www.ultravioletphotography.com/content/index.php/topic/4412-new-camera-first-tests-and-a-long-story-to-tell Link to comment
colinbm Posted July 22, 2021 Share Posted July 22, 2021 I must be doing something wrong ..... ?I shine the light at or through the Quartz or ZWB1 & it appears clear to the full spectrum camera ? Link to comment
Stefano Posted July 22, 2021 Share Posted July 22, 2021 Quartz is ~100% transparent in UV, so it has no color. ZWB1/ZWB2 glass peaks at 340-360 nm, and that gives it its yellow tint. Link to comment
Stefano Posted July 22, 2021 Share Posted July 22, 2021 If you are using a 365 nm LED for example, the image you get doesn't show much color. If you use sunlight or a full-spectrum flash you will get more colors. Link to comment
colinbm Posted July 22, 2021 Share Posted July 22, 2021 I tried the U340 in the Sun & it was clear on the full spectrum camera ?The example I showed this morning of the quartz was clear but showed yellow in UVA ? Link to comment
Stefano Posted July 22, 2021 Share Posted July 22, 2021 Your quartz example is yellow because of fluorescence (and the quartz isn't actually fluorescent, but appears yellow because of the yellow light coming from above). What I did is reflected UV photography of U-glass. Try to take a normal UV photo of a UV-pass filter on a block of PTFE, with a white balance applied. It should look yellow. Link to comment
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