colinbm Posted October 9, 2022 Share Posted October 9, 2022 [UV SAFETY] UV-C Light Is Dangerous NEVER look at a UV-C light. NEVER let UV-C light hit your skin or eyes directly or by reflection. UV-C light can cause: severe burns of the eyes and the skin, and DNA damage from broken chromosomes. When working with UV-C illumination, you MUST: cover up completely, wear head & eye protection, and have strong ventilation. UVIVF, UltraViolet Induced Visible Fluorescence, with many UVA, UVB, UVC, LED lights & Far UVC Excimer lights. I now have a collection of UV LED lights, 365nm, 340nm, 310nm, 395nm, 375nm, 365nm, 255nm & 222nm Excimer Far UVC lights. I have been developing my Macro set-up & light stands. These are taken with an unconverted Sigma fp camera with a Sigma 70mm macro lens. The rock/mineral sample is one in my collection from the Puttapa Zinc Mine, South Australia, & contains willemite, calcite & smithsonite, plus others. I have tried to process these all in a simple & similar way. I have adjusted the shutter speed & aperture to maximise the dynamic range in the histogram to fill it from left to right. Processing has been minimal to white balance on the black cap the rock is sitting on & sharpened in Topaz Sharpen AI. First in Visible Light 400nm - 700nm. Far UVC 222nm Excimer Light, Induced Visible Fluorescence, safer to use. Protect eyes, face & all skin. UVC 255nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVC 265nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVC 275nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVB 295nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVB 310nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVA 340nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. UVA 365nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Link to comment
dabateman Posted October 9, 2022 Share Posted October 9, 2022 Colin, amazing. The differences between them makes it worth it. I wouldn't have predicted so much difference between the 222nm, 255nm, 265nm and 275nm leds. Looks like you have it working and ready to discover some new rock fluorescence. Link to comment
lukaszgryglicki Posted October 9, 2022 Share Posted October 9, 2022 Great photos, what are you using as 222nm light source? Link to comment
JMC Posted October 9, 2022 Share Posted October 9, 2022 Fab pictures Colin. The 222nm in particular is quite striking. Link to comment
Stefano Posted October 9, 2022 Share Posted October 9, 2022 Very cool! You can see the gradual change between wavelengths. Link to comment
Kai Posted October 9, 2022 Share Posted October 9, 2022 Great work Colin! Like it a lot. Thank you for sharing :) Link to comment
colinbm Posted October 10, 2022 Author Share Posted October 10, 2022 Thanks everybody for looking & commenting. @lukaszgryglicki I have used BBTUV.com & SuntechLeds.com 60watt 222nm Far UVC Excimer tubes, but these are the better filter IMHO, https://www.suntechleds.com/far-uvc-lamp-light/far-uvc-excimer-light-accessory/far-uvc-filter/uv-filter-222-nm-optical-bandpass-for-far-uvc.html Link to comment
lukaszgryglicki Posted October 10, 2022 Share Posted October 10, 2022 Thanks for info. Link to comment
Wayne Harridge Posted October 11, 2022 Share Posted October 11, 2022 Great stuff Colin! Images get more interesting as you reduce the wavelength of the exciting UV. Are these effects used for determining the composition of mineral specimens? Is there such a thing as UV induced visible spectroscopy? Link to comment
colinbm Posted October 11, 2022 Author Share Posted October 11, 2022 Thanks Wayne It can only be an aid to identifying from the same location. The same mineral at a different location can have different colours. Yes you can do UV induced visible spectroscopy, but I can not. Here is a example borrowed of the net..... Link to comment
Doug A Posted October 11, 2022 Share Posted October 11, 2022 Fabulous photos. Never expected such dramatic color changes. Do most fluorescent rocks exhibit this much variation, or is this a very special specimen? What would UV electronic flash look like? Do the colors track the greatest NM flash output? Thanks for sharing, Doug A Link to comment
colinbm Posted October 11, 2022 Author Share Posted October 11, 2022 Thanks Doug Yes most minerals exhibit different visible fluorescence when excited with different UV wavelengths. UV Xenon flash doesn't go this deep, but the longer wavelength UV will give a similar visible fluorescence if a narrow band filter is used. Link to comment
Andrea B. Posted February 28, 2023 Share Posted February 28, 2023 i was on leave-of-absence and missed this last October. It is an excellent illustration of the effects of different UV wavelengths. Nicely done, Co! Link to comment
colinbm Posted February 28, 2023 Author Share Posted February 28, 2023 @Andrea B. Thank you I intend to go back to this with the microscope objectives one day soon. Link to comment
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