I finally got everything together and wanted to post this. First off, I am a real newbie and have relied heavily on the advice and knowledge of the great BLF community. I missed out on the heyday of UV light building here, which was really active in 2015-2016. Anyone interested in UV builds should search some of the old threads here. However there still seems to be some interest and activity in UV lights with djozz testing new emitters when they come out. I came to UV flashlights through the mineral collecting community. If you want to read about it check out this web site Nature’s Rainbow .
Safety notice: UV light is dangerous for your eyes. Do not look into the beam and be sure to wear protective glasses when using a strong UV flashlight. Reflections off shiny surfaces can direct the beam into your eyes by mistake. You won’t know you have damaged your eyes until you get a case of “snow blindness” caused by the UV burning your retina.
I had purchased the Convoy S2+ with Nichia emitter based on recommendations at Nature’s Rainbows and here. If anyone is thinking of getting a UV light I highly recommend this light to start with. Be sure it has the Nichia emitter and get a ZWB2 filter to reduce visible light. While this light works great, reading on BLF naturally encourages one to do more. I monitored the discussions of the Sofirn C8F light on BLF with great interest since it is a triple emitter and there is was a cheap host available. I got one along with their DTP board and driver. And thanks to a recent review by djozz on the Luminus SST-10 emitter here https://budgetlightforum.com/t/-/48736 I got three of these from Digikey.
These were quite easily reflowed onto the Sofirn DTP board (thank you for the great tutorial VestureofBlood!). It was my first reflow and worked great.
The light went together without too much trouble although I left the wires long and had a hard time stuffing them into the space below the driver. And believe it or not it worked the first time!
This is the view of emitters on moonlight mode without a front filter. Don’t worry I was wearing my safety glasses while taking pictures. The only remaining requirement was to get a filter for the front of the flashlight to reduce the visible light emission. I managed to find a 50x50mm piece of ZWB3 glass on ebay for not too much ($16). I know, the ZWB2 filter is the main one used for 365nm but this glass seems to work about as well. I had to cut the glass down with a saw
and then smoothed out the cuts using a grinding wheel. DBCustom mentions doing this in his builds years ago.
So this is what it looks like with a 42mm filter glass in place
But how does it work? Well I tried wall shots like most of the other beam shots on here but my wallboard doesn’t really fluoresce well. So I put up a sheet on the wall. Because whiteners used in washing it fluoresce nicely this seemed to provide a good way to compare the C8F with the S2. In this comparison both lights have a filter on, ZWB2 on the S2 and ZWB3 on the C8F.
On the left is the Convoy S2+ and on the right is the C8F. The S2+ has an orange peel reflector whereas the C8F has smooth reflectors. Unfortunately Imgur did some strange things when converting the images so the differences are not exactly as they look in real life. The left image is the C8F on Low2, middle is Medium and right is High2, only in Group 1. The S2+ is has only one mode.
The S2+ hot spot is a little more spread out than the C8F. On Low 2 the hot spot for the C8F looks almost as bright as the C8F, maybe a little lower. However the Medium and High 2 are clearly much brighter than the S2+. Success! Oh yes, I should mention that both lights have the same freshly charged battery from a laptop pull that I did. With a good high draw battery the C8F could be even brighter. I haven’t had the guts to try it on Turbo yet as I really don’t want to smoke the emitters. From what I have read Turbo can go up to close to 9A. The test by djozz only goes up to 2A for the SST-10 so as a newbie I am scared of pushing them too hard.
As for people who want to know about visible light emission, here is a comparison of both lights without filters. Again S2+
on the left and C8F on the right (C8F on Low2). To my eye they look about the same but in the image the S2+ (Nichia) looks much worse. As the Nichia is noted for having very low visible light emission I have to say that I think the SST-10 is about as good.
Again Imgur introduced some awful artifacts when converting the image. I should state that all of the beam shots were taken with my Nikon D5100 using manual mode to prevent differences between images. So my little adventure has met with success and I have a nicely portable light that I can take in the field with me. Here are some pics of a few of my fluorescent specimens for your viewing pleasure.
This is the same Low2, Middle and High2 settings used in the previous images. They are, clockwise from the top left, blue fluorite from Illinois, yellow sodalite from Canada, pink calcite from New Mexico and reddish bladed hexagonite from New York. You can clearly see the intensity of the fluorescence increasing from left to right. So all in all I am very happy. Hope you enjoyed reading and I will look forward to questions and comments. And again thanks to the inventive BLF community. I never would have been able to do this without your help.