Hello everyone, I’m relatively new to the world of flashlight mods and could use some guidance.
I am a scientist interested in biofluorescence and I have created some simple flashlights to help me avoid spending thousands on expensive custom rigs.
I have installed Cree royal blue XT-E chips (455nm) in flashlights that I used in amphibian research, but these single-LED flashlights are not bright enough for me to effectively photograph specimens in the future.
I am looking for a base flashlight with 5-6 LED mounts compatible with the XT-E that I can easily solder these chips into.
I have had success replacing the CREE XM-L2’s in cheap Bluefire flashlights. But I had to fully replace the star PCB board in these lights as the CREE XM-L2 is 5x5mm and the XT-E is 3.45x3.45mm. Maybe there are lights that already contain multiple white XT-E’s I can swap out?
I have seen on this forum lights like the KDLITKER E6 that can have modules dropped in with blue XP-E2, these modules may have the potential to have the XT-E’s soldered in, but would only support 3 chips. I may pick on up just to experiment.
The light will be used primarily for photography and, so it does not need to be designed for focusing long-distance.
A dive light that can be redesigned would be great, but I haven’t found anything compatible in my searching.
Maybe I should try creating a totally custom housing using plexiglass, PCB boards, and 26650 batteries? I hoped to avoid this option because it seems extremely complicated for a beginner like me.
XT-E important specs:
Size: 3.45 x 3.45 mm
Max Drive Current: 1.5A
Forward V: 2.85 V @ 350 mA
IN SUMMARY: I could use some help finding a XT-E compatible flashlight (lights with XM-L2’s work) with 5+ LED mounts or suggestions on building a custom rechargeable rig if the first option isn’t feasible.
I would greatly appreciate any suggestions.
Note: Some might questing why other royal blue LED’s won’t work, and the answer is that the XTEARY-00-0000-
000000Q04 has a very narrow bandwidth of 450-455nm that is what has been shown to induce fluorescence in the animals I work with, while other LEDs have large bandwidths like 450-470nm that result in the fluorescence getting muddled or covered up by light from less-reactive wavelengths.
Interesting note about the fwhm of the XTEs spectrum. Something like an Emisar DT8 might prove sufficient? How long of exposure i.e. on time of the light do you need? Does it need to be portable/handheld or is this being mounted on a bench/tripod for example?
Something fully DIY might be the answer here. I envision a few series wired triple DTP mcpcb’s mounted to a CPU heatsink and powered by a bench power supply.
I’m guessing output pwm can be an issue for you as well?
jon_slider, this looks very promising, I checked out the website and I’ll shoot him an email, thank you!
JaredM, the unit does need to be mobile for examining species in the field. The exposure does not have to be long, I have even considered constructing a custom camera flash. I may still make a immobile unit like the one you suggested for brining specimens in, or maybe try powered lights with a heatsink for a mobile unit.
EasyB, I want it to be as bright as possible while still being somewhat mobile. It would be ideal to have the brightness be constant regardless of battery life. I haven’t tried overdriving the XTE’s, it won’t damage them?
This is really interesting. Do you happen to have any photos that you’d be willing to share? I took an interest in UV fluorescence and have been quite surprised at all there is to learn, and at the variety of things/colors/amounts there are to see even without specialized equipment.
So yes, the footprint is the very common 3535 size (most often called XP-L type in the flashlight world). I don’t know about the colored emitters but the white ones can generally be heartily overdriven far past the “max” stated in the datasheets. The datasheets are very conservative with the figures and are geared toward low heat and/or longevity for product designers. Almost all Cree white emitters are very robust with a pretty long steep curve of increasing output before too much current will do them in (for instance, many will happily handle 6 amps and many a lot more than that so long as they are operated smartly with either a power switch, timed stepdown in the driver, or temperature regulated stepdown in the driver). UV emitters are a certain exception there, and most of those that I’ve seen really need to stick fairly close to the datasheet specs or they’ll cook, just a small amount of overdriving is acceptable with them. So…that tells you nothing about Cree 450nm blue, though.
If we can determine that better, then it sounds like you could use any number of flashlights on the market that use the XP-L 3535 footprint and have driver modes that give acceptable current, and simple disassemble and swap emitters on the mcpcb board already in the light. With only three emitters it may not be attractive to you, but if they are driven a bit harder than what you’re used to (datasheet) it may suit your needs just great. And if you get one that has ramping firmware (Anduril, some from Sofirn and Wurkkos, etc) then you can dial in the light levels to suit photography needs. I’ve done this with a Sofirn C8F and UV emitters and love it. And if a triple isn’t enough then there are quads or some other more expensive options. If Hank is able and willing to do a one-off light for you, I think you’d certainly end up with exactly what you want, and he’d make sure that the driver is well matched to the emitters.
Another thought I had was bandpass filter glass. Is that an option for you? The Tansinuo optics store on aliexpress has a really wide range available and are very receptive to custom orders as well. I see some 450nm options listed and they’re labeling them as narrow, but their graphs make me wonder a little (you might know better). If these would work with white emitters then maybe some combo of white flashlight with the lens would be an easy no-solder solution, or perhaps they could be used along with the XT blue emitters to crop stray waves (we do the same with UV emitters and the associated filters).
A link to their “custom” product page but you can check the other product links in the sidebar or search the store….or just message them. I’ve ordered from them a couple times and they were super helpful, seem like a very professional outfit (not too many of those on aliexpress….).
Thanks for linking this test. I was thinking about suggesting this, but I’m not sure of the fwhm of the blue pump spectrum. I have an SFT40 that I’ve scraped the phosphor off and am going to eventually get around to testing that one. I wouldn’t be surprised if we see 20A from that one.
Correllux, thanks for the reccomendations. I'll share some images of amphibians from my research. I investigated bandpass filters like some companies use for fluorescence work and I believe the broader FWHM of these filters would result in too much noise from nonreactive wavelengths. Here is a graph from my work in regards to bandwidth and fluorescence:
https://drive.google.com/file/d/1-ezTv_VfOm8MBEA-twWae87J2lRcMzYn/preview
Image of frog:
https://drive.google.com/file/d/1bZgjcprMx6J_8M0PfAFCnPo5RW_VIeuX/preview
Image of newt:
https://drive.google.com/file/d/1YFetE_eJTDrKANrtAIQA7XwyRGqEkevh/preview
Flightless22, I appreciate the recommendations, but if you check out the graph I linked to Correllux you’ll see how I’m kinda pigeonholed on what LED I use because of bandwidth.
I’ll keep talking to hank, he says lots of his lights work with the XTE chips. Maybe it’ll be an easy swap, sometimes I have found it very difficult to swap out these LED’s because of how small they are. I have had the best luck attaching them to star PCBs on a hot plate using paste solder. Maybe you guys have a recommendation for guides on soldering tiny chips like these?
Also something I would like to note here is that one of my long-term crazy ideas would be to go a few steps further than a custom blue light. I would really love to make a light that features an array of UV LEDs, blue LEDs, green LEDs, and red LEDs. A controller would combine the different colored LEDs to produce different wavelengths (just like a monitor). I could use an optical probe to calibrate the different ratios to produce the different wavelengths. This way I could go out in the field and dial in exactly what wavelength an organism responds to. For instance, I might find that animals use longer wavelengths of light to fluoresce in deeper water or foliage than their counterparts in shallower water/foliage because the longer wavelengths penetrate deeper. I wouldn’t even know where to begin with this design though. I would need a simple computer that could easily be programmed to dim these different arrays, not to mention a DIY rechargeable battery and waterproof housing.
That’s pretty neat…thank you for sharing those. Makes you wonder why on earth they might fluoresce and what purpose or benefit (if any) it serves. Kind of like scorpions but they’ve come up with some very good theories about that which seem pretty plausible - but then there are the reactions to different wavelengths and variations between different scorpions, too. But for an amphibian that doesn’t ever expose its ventral side if it can help it…whyfor, then? And is it “activated” by reflection/refraction of sunlight in the water? Maybe the answer is in the eyesight of fish. Or maybe it’s a byproduct of a healthy mateable frog.
Newt feet look a lot like armadillo feet…if anyone ever asks.
Swapping emitters is best done outside the light just as you have. I suppose with a wide and very hot chisel tip they could be done in the light head but I’d be concerned with possibly overheating the dies, maybe damaging the domes, or the solder mask on the mcpcb. With the board attached in the light, the design is doing its job and sucking all that heat away to the body metal/pill so it’s much harder to get enough heat there without going overkill. It’s just a bit more effort to remove the star, more on some lights than others, but much better all around. Some of the tiny smd aux leds are easy to do with an iron whether they’re mounted on pcb boards or stars. I don’t know if I’d trust hot air from the top…maybe in skilled hands.
Oh, on sharing images….this site only links to external hosts. Many people use imgr but some have trouble viewing those. https://postimages.org/ is a good alternative and seems to work for everyone. Drive works, too. You can direct link or you can embed them in your messages using the toolbar icon at the top of the box (for some reason the simple editor here always works better for me with image links than the advanced editor).
As far as why they would be ventrally fluorescent, your guess is as good as mine. I wondered if maybe when they leaped it produces a flash of fluorescence to entice mates or confuse predators. There is probably detectable fluorescence in refracted sunlight, but whether it is detectable by amphibian vision is something that would have to be tested. It is also possible that these pigments being fluorescent is purely coincidence with no measurable effect on fitness (but I think this hypothesis is unlikely). The fluorescence observed in the lymph glands of a species of South American frogs did have emission patterns that very well matched amphibian vision - possibly indicating it has sexual significance.
We’ve learned so much and yet there’s so much more to learn…it’s awesome. I just sit on the sidelines and read articles and findings but I sure appreciate the people like you that are doing the work! Do keep us updated on the light and the work if you can…may not be many people seeing this thread right now with the holidays but I’m sure there are many who share the interest and fascination (about the emitters and Light, too, of course).
Do you have the LEDs you want to use or a supplier that has them —- Seems like it would be nothing to build a Triple or Quad with them — If you want to spend some money — Talk to Vinh — He has that 12 LED board that he builds mules with —Looks like Richard could help you to at Mountain Electronics
Chops728, I do have a Cree model I have tested from mouser. Maybe I can order components from one of these sites. I am new to the world of custom flashlights, what is a mule?
