dabateman Posted August 13, 2020 Share Posted August 13, 2020 A m42 to cmount adapter will fit inside. Then a 5mm c-mount extension can be used to slightly focus the beam. I like the look better than the one not adapted. I can also keep the green ring to know its on, as the adapter blocks its fluorescence.It does emit a strong fluorescence signal that I could pick up on my spectrometer. It also continues to fluorescence for a long time after the light is off. Link to comment
Cadmium Posted August 13, 2020 Share Posted August 13, 2020 Yes, That's what I meant M42. Andy, I hadn't thought about the heat... this thing does seem to have some heat out in front of it, which any filter on the front would be subjected to. Like I said, I have not played with this long enough to get a good idea about how hot it gets, but I might not start with the UG11, if it is real UG11 then it is twice the price of real U-340. If it is non-real (AKA Chinese glass labeled as whatever...), then the price might be OK for testing. Here is a size comparison: Link to comment
Cadmium Posted August 14, 2020 Share Posted August 14, 2020 Stupid question. Why are the batteries so big? 3.7v, 8800mAh (the ones I got, well supposedly, who really knows). Link to comment
dabateman Posted August 14, 2020 Share Posted August 14, 2020 Stupid question. Why are the batteries so big? 3.7v, 8800mAh (the ones I got, well supposedly, who really knows). Doesn't Ulf answer this question in his 2nd and 3rd sentence in the first post? Link to comment
dabateman Posted August 15, 2020 Share Posted August 15, 2020 I fully charged up the batteries that came with my lights and scanned them. One thing Ulf doesn't have posted is the fluorescence that comes off the green ring. I was able to capture that. This is the plot which shows the light off the green ring: To correct what I see with my lights. When the green ring was in front of the ZWB2 filter the peak max I got was 366.752 on one light. But now that I have moved the green rings behind the ZWB2 filter and placed a M42 to C-mount ring on both lights I seem to consistently get 367.478nm for both lights. This may also be a warm up thing as I had them on for a while to play with them and look at their intensities. One of my lights is brighter than the other. And my new Convoys which scanned at 367.115 repeatedly today were not too far off visually in intensity then these Nemo lights. I didn't capture an image with a full spectrum camera to properly compare intensity, this is just what I see in a dark room illuminating the dust off my socks. Link to comment
Cadmium Posted August 15, 2020 Share Posted August 15, 2020 If you put a UV blocking filter over the torch, you will see no fluorescence, but the green O-ring will still be clearly seen, and the green glow from the O-ring will illuminate a close target.It is up to the user if the target is far enough away to not be concerned with whatever minimal green might be added to the mix.I used a Zeiss T* for my test. Link to comment
colinbm Posted August 15, 2020 Share Posted August 15, 2020 Dave, why the M42 to C-mount ? Link to comment
dabateman Posted August 15, 2020 Share Posted August 15, 2020 Dave, why the M42 to C-mount ?It focuses the beam when used handheld.But also allows me to use the standard c-mount to screw it in as a direct light path for microscopy and spectroscopy experiments. Link to comment
ulf Posted August 15, 2020 Author Share Posted August 15, 2020 Be careful if you really are focusing the beam, with some lens in that setup, David.That would create quite high energy density, just like Stefano's dangerous experiments some months ago. Link to comment
Stefano Posted August 15, 2020 Share Posted August 15, 2020 Yes, it must be said that you can't create a laser-like beam with that power density, when you do what I did you get a rapidly diverging cone, and the burning spot is maybe a 5 mm × 5 mm × 5 mm cube (it isn't cube-shaped of course, just to give an idea), so very limited and located in a specific place in space. My LED was similar to the LED in the Nemo torch, but mine was rated for 10 W, this claims 15 W (has anyone measured the power consumption?), so probably you can burn paper, light a match, and have some fun like I did. I don't exactly advise anyone to do what I did, maybe don't do that in your bedroom if you really want to. Link to comment
dabateman Posted August 15, 2020 Share Posted August 15, 2020 Thanks Ulf,I have no interest in focusing or intensifying the beam. Collecting it into a fiber is a better word. With losses. Then spreading it over a slide or accross the width of a cuvette, may paint a better picture. Link to comment
Andy Perrin Posted August 15, 2020 Share Posted August 15, 2020 You want to columnate it, I think? So the rays are parallel. I know ThorLabs sells lenses that do that and they have adapters for every thread imaginable. Link to comment
dabateman Posted August 15, 2020 Share Posted August 15, 2020 Yes my 25mm bicx element actually works wonders for doing that and its fused silica. So it covers all wavelengths. Its in a c-mount 5mm adapter. Which is why c-mount works well for me. Then I have an adapter that I made to SMA 905 to tie into the fiber. I then have a large fused silica adapter on the end of a fiber for microscope slide illumination.bor use my cuvette holder to tie in there. The PMMA cuvettes are good enough for what I need and are disposable.I just now really need to solve the excreted potassium detection problem fromthe cells I am looking at. PBFI is really expensive, so still hoping I can use an autofluorecence assay as my cells are stressed.I need to think through this more clearly. Link to comment
ulf Posted August 17, 2020 Author Share Posted August 17, 2020 For 365nm it does not have to be fused silica.If that is not available, BK7 works just as well. Link to comment
ulf Posted August 17, 2020 Author Share Posted August 17, 2020 If there is a need for a small area illumination that is even a rigid short light guide like this can be used:https://www.ebay.com...ar=691643939436For some reason I have one of those and decided to design and 3d-print a suitable adapter.I made it slightly longer than the combination of the reflector filter and rubber ring to maintain the pressure on the LED's metal-PCB. The light-guide fits snuggly into the hole and ends just above the LED's lens, coupling almost all UV-light into the guide. At the end of the light guide the UV-light is very intense, almost as bright as directly above the LED's lens, then decaying quickly with increased distance. During the first fitting of the parts I leaned that the white bezel around the LED is made of plastic and just pushed into place.It's purpose is to guide the LED and reflector to an optimal position. It came off as the hole in the 3d-print by mistake was slightly too snug, as well. The LED's PCB came lose and I noticed that the cables were long enough to allow adding some quality thermal paste between the PCB and aluminium structure. Link to comment
Andy Perrin Posted August 17, 2020 Share Posted August 17, 2020 That is a nice build. Based on Stefano's experiments with burning things, I am not sure I would leave the end of the light guide on the paper like that! With such a high intensity, I bet you could see some interesting fluorescence in any material that can stand the heat long enough for a photo. Link to comment
ulf Posted August 17, 2020 Author Share Posted August 17, 2020 I agree, only long enough to take the picture!!The intensity in the light spot is rather even but decays fast as the spread angle is wide. BTW I used ABS for the 3d-print. The melt point is rather high and the LED would be dead before the plastic melts.The printing temperature was 245°C in the extruding nozzle. Link to comment
Stefano Posted August 17, 2020 Share Posted August 17, 2020 You can always add a lens to have a narrower beam. I bet you can feel heat on your skin in front of that light guide. It looks like you are spraying light from the tube. I wonder what people would think seeing someone illuminating flowers at night with that thing. Link to comment
Andy Perrin Posted August 17, 2020 Share Posted August 17, 2020 Many people have seen me out taking photos at night with the tripod and all, and I've yet to get even a question! I think people are hesitant to approach. Link to comment
dabateman Posted August 17, 2020 Share Posted August 17, 2020 Many people have seen me out taking photos at night with the tripod and all, and I've yet to get even a question! I think people are hesitant to approach. If you really want to keep people away. Get a $30 hazmat suit off Amazon and a Geiger counter when your out at night taking photos.If someone comes close sweap them with the Geiger counter in lowest or calibration mode and shake your head. Link to comment
Cadmium Posted August 19, 2020 Share Posted August 19, 2020 Update to my previous post:https://www.ultravioletphotography.com/content/index.php/topic/4051-convoy-s2-has-a-challenger/page__view__findpost__p__38256 The 42mm to 52mm step up ring doesn't have enough thread depth to screw into the front of the Nemo. The Nemo threads start at about 2+mm inside the front.Have to find something with longer threads. Link to comment
dabateman Posted September 23, 2020 Share Posted September 23, 2020 Have you found a good battery for them? Something Ulf recommend with low resistance. Link to comment
Cadmium Posted September 23, 2020 Share Posted September 23, 2020 I have no idea. Nothing to compare. These are the first and only 26650 I have so far. These work fine. I purchased these batteries separately from the 'Nemo' torches.Ask Ulf for battery test comparisons and suggestions.I have tried and compared many 18850 batteries for the Convoys and MTEs, some of which are inexpensive, and others are premium quality, and I have not noticed any difference between them in the brightness or run time.I often use the Convoys for 45 minutes, and get to compare.Here is the place John recommended years back. I have purchased some premium batteries there.https://liionwholesale.com/ Link to comment
ulf Posted September 23, 2020 Author Share Posted September 23, 2020 I have been playing with the idea to create an end-cap for the lamp head, containing a DCDC-converter and connection to a suitable USB current source like a Power Bank or USB adapter. That can be handy for more permanent shooting setups, lighter and smaller than the whole torch with it's battery. Then there will not be any risk of losing intensity to a low battery voltage. The DCDC-board in the picture fits the inside diameter of the battery tube or in this case end cap. It can deliver more than the needed 1.8A and step the 5V down so an optimal 3.8V after adjustment. The cap can easily be 3D-printed and I think I will give it a hole with a 1/4" camera-thread, on the side, for mounting on something like a small ball head. The rather fine threads on the lamp head will not be possible to 3d-print well for me, but I can make a well working self threading structure. The easiest way to build this is with a fixed USB-cable, exiting at the backside of the cap. I am open for suggestions and opinions about this idea. Is it usable for others than just me? If it turns out to be easy to make and build, I might make a few more than the two or three I need, myself. The materials cost is not very high. Link to comment
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