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There's two types of upconversion phosphors: the "direct" ones, that absorb multiple low-energy photons to emit one higher-energy photon, and the "storage" ones, that must be charged with high-energy light (such as UV) and release their stored energy as photons when illuminated by IR light. MaxMax sells both, and below is a video of a comparison between two storage phosphors: What I noticed is how bright they are. The laser pointer used in the video is probably also quite powerful, but direct upconversion phosphors are very inefficient. [Edit: in the comments the author of the video says the laser is 980 nm, 100 mW] Andy has experimented with them (read this topic), and he can tell you he needed a lot of light. Of course the problem is that these phosphors need to be charged. If one wants to take video, then one way is to flash the phosphor in the blind times between frames, somehow synchronizing the flashes with the camera sensor (or maybe even continuously illuminating the phosphor and imaging it through a longpass filter that blocks the charging light). The storage phosphors sold by MaxMax (in the video above) are rated to respond between 700 and 1500 nm. To my knowledge, this techique hasn't been tried yet.

Several of these on eBay, priced between about $1,200 and $1,700. All from China, apparently from different vendors (although they may be related). Resolution should be 320x256. Example: https://www.ebay.it/itm/304980132465?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=fcdsnphwro-&sssrc=4429486&ssuid=kmqj_e1bqvo&var=&widget_ver=artemis&media=COPY

I finally figured out all the settings with my InGaAs linescan camera setup. Here are the first photos. Most of them full InGaAs spectrum, I still don't have my 1575nm bandpass filter - it should look even nicer with a filter. I used a VIS Nikon 50mm lens.. A proper SWIR lens wouldn't make big difference regarding the resolution, especially with the bandpass filter. The VIS lens has however only 40% average transmission in SWIR. Landscape SWIR 800-1700nm VIS (400-800nm for comparison) The next is isopropanol and water (800-1700nm) VIS (400-800nm) Another mountain SWIR (800-1700nm) SWIR with uncoated silicon wafer filter (ca. 1100-1700nm) VIS (400-800nm) VIS full spectrum (400-1200nm) with my ASI294MM (monochrome CMOS) and 50mm lens And finally ASI294MM with 860nm longpass (860-1200nm) I still like this last photo the most, but I'm very excited to discover more SWIR . :)

My interest in light didn't end when I studied laser physics in Hungary and didn't start in the UK while developing high power lasers. I'm now in Switzerland focused on the infrared part of the spectrum, NIR, SWIR, hyperspectral, multispectral. Continously collecting light: line and area scan cameras, optical simulations, spectrometers, slit goggles.. I'm DIY-optics (dot com) himself. ;) You have a very nice community here, I appreciate being a new member. Hello Everyone

Don't get too excited. Despite the grand title, the results are a little disappointing. Part of this is the fault of my equipment being insufficient for the job, but a lot of it is apparently the moon's fault. It just doesn't vary that much with wavelength, seemingly! But a negative result is still a result as they say, so here you are... Equipment -TriWave camera (germanium-on-CMOS sensor), which has sensitivity from 350-1600nm -Thorlabs 1" 100mm mounted achromatic doublet lens, AR-coated for 1050-1700nm -Thorlabs SM1 Lever-actuated Iris Diaphragm (for controlling aperture) -Thorlabs Filter Mount with Sliding Modular Inserts (with a bunch of the inserts for holding my filters. These are very convenient. You slide the filters back and forth for quick swaps.) -Various Thorlabs SM1 tubes and C-mount adaptors for hooking things together and holding them at the correct distance. -The filters are a mix of Omega seconds from eBay for NIR, and high quality Thorlabs filters in the SWIR (1200nm+). -INOGENI USB 3.0 NTSC video capture card (because the TriWave is analog output) Software - Custom written MATLAB code for snapping bursts of images and saving them - Lynkeos astronomy software for aligning images and weeding out low quality ones - Photoshop Resolution was severely limited by the optics in this case, although the TriWave is only 640x480. I was using only about 128x128px of that, however, due to the 100mm lens. If I get a longer lens, I may try again with higher resolution. Each of these individual images is boiled down from a stack of 600 photos each, but the Lynkeos software throws out many of the bad frames before the rest are averaged together.

I do not remember seeing anything here about this camera: https://trieye.tech/ovi/ I just found it in a newsletter for optical components and know nothing more about it.

SAFETY WARNING: UV-C is dangerous to your eyes and your skin. UVP DOES NOT SUPPORT USING UV-C ILLUMINATION. [UV SAFETY] UV-C Light Dangers A short YouTube video that includes a 254 nm clip: https://youtu.be/CaXzgumCn34. The gear they use is interesting.

"Silicon inspection uses next-generation SWIR cameras" https://www.laserfocusworld.com/detectors-imaging/article/14196038/silicon-inspection-uses-nextgeneration-swir-cameras?utm_source=LFW+Detectors&utm_medium=email&utm_campaign=CPS210224014&o_eid=1758A2788401D4U&rdx.ident%5Bpull%5D=omeda%7C1758A2788401D4U&oly_enc_id=1758A2788401D4U This is the kind of equipment we may hope to find on the second-hand market in maybe 5 to 10 years.

Is it a metaphor, or just water drying in SWIR? You decide! 1450nm, water on paper. https://youtube.com/zC5et6slLCQ

After a great deal of work, I have figured out how to access the video feed from my TriWave in MATLAB, and I've written a program to capture time lapses and process the resulting frames. Each frame of video is actually 120 frames from the camera (4 seconds' worth) averaged together, and this is repeated once a minute. This video took 90 minutes in real life, but's 13 seconds of video, or about 415 times faster than reality. Lens: Wollensak Velostigmat 25mm/1.4 Filter: Thorlabs FB1450-12 (1450nm, 12nm FWHM) https://youtube.com/dEgNbJj6NWU YouTube's compression really degrades it. ---- Update: I repeated the experiment at 1250nm. For some reason the Triwave is significantly less sensitive at 1250nm. (Or my lens has lower transmission that at 1450nm? Unlikely.) I don't THINK it's the filter, since the peak transmission is 50%-ish for the 1250nm but 30%-ish for the 1450nm, and the bandwidth is almost the same. ANYway, excuse my noise. Filter: Thorlabs FB1250-10. https://youtube.com/Br3hr_6Z7Tc

As previously discussed, ice and water have different spectra in SWIR. You can see this pretty graphically demonstrated when you watch a snowflake melt. https://youtube.com/5zNsfJMPaHg https://youtube.com/kzp6lH52hW8

I finally redid my pano today, thanks to the overcast weather. (Link to previous attempt) When the sun is out, my mere 10 bits of dynamic range are not enough to capture everything in the photo. It becomes like trying to photograph the moon AND the stars simultaneously -- pick one! Even so, there was enough variation in the photo that I had some trouble stitching the bottom edge with all that black snow. The snow seemed much darker today, which is probably a sign of the thaw, since it was well above 0 deg C. Details are the same as the last attempt except that I stitched in Hugin. Visible (today) Previous pano for comparison purposes. We have had additional snow + melting in the interim.

Here's a tricolor of snow on a window. The filters are: 780BP30 - red channel 1064BP25 - green channel 1500 long pass (but probably 1500-1550 effectively because of the camera gain fall off) - blue channel The color channels are BGR essentially because it made the snow stand out better. Alternative is to have magenta cyan snow in RGB. visible: Individual frames: 780nm ("red") 1064nm ("green") 1500nm ("blue")

Consider this a first attempt, which I plan to update or replace tomorrow when it's light out again. I started a SWIR pano of the snowy landscape out my window but unfortunately the sun set before I could finish. Oh well. In addition to missing data, there are some obvious places where the lighting changed between captures. I will try again! Equipment TriWave Ge-CMOS sensor camera Wollensak Velostigmat 25mm lens (but the camera has a 1/2" sensor, so there is a huge crop factor of around 5.4, so the effective focal length is about 135mm) 1500nm long pass filter from Thorlabs Tripod Software TriWave driver software (seems to be custom coded for this particular camera -- I definitely think my camera must have been a prototype) Custom MATLAB script to batch process the images and prepare them for the panorama, including subtracting off fixed pattern noise from the sensor Photoshop CS6 SmartDeblur for deconvolving the image to sharpen it Observations - ice and water have different absorption curves and it's definitely possible to distinguish wet snow (black areas near windows and on the ground) from well-frozen snow (the gray on the roofs). ETA: it seems ice absorbs more light than water at 1500nm, not less, so my updated hypothesis is that the contrast is due to less scattering between ice/water interfaces than between ice/air interfaces. See discussion below. - brick has gorgeous patterns in SWIR

I saw this on eBay: https://www.ebay.co.uk/itm/333795972392 It is a SWIR camera which is "non functioning and for replacement parts" (translated from Italian, this may not be how the message appears in English). I think there is everything except the lens, maybe someone could be able to repair it and make it work? What do you think?

A friend (who I am hoping to entice to join the forum one of these days) sent me a link to this company, which seeks to make some kind of low-cost SWIR using CMOS(!) of all things. https://trieye.tech/products/

I have had occasion to notice that a number of flowers start to show colors again in SWIR, and it turns out that the tiny flowers (florets?? I don't have the vocabulary down, although I'm sure Birna could help) on Queen Anne's Lace have dark centers at 1500nm. The darkening starts before then and is visible also in the longer wavelength parts of NIR. Using the TriWave (which has a germanium-on-silicon sensor with range 350-1600nm), I made the following "true color" IR image from two Omega bandpass filters and a Thorlabs longpass (but effectively a bandpass since it's at the end of my sensor's range of 1600nm). - 1500nm hard coated premium edgepass from Thorlabs (blocked OD5+ through 200nm, which is rather important with the Triwave since it's much more sensitive in visible than at 1500nm+). - 1064BP25 Omega - 780BP30 Omega These were placed in the R, G, and B channels respectively to produce the following image: The image has been processed by registration of the channels, contrast adjustment, noise reduction, sharpening, and boosting saturation. Original images: 1500nm-1600nm (but probably mostly 1500-1550nm because the TriWave's gain falls quickly in that range): 1064nm: 780nm: This result is startling given that in visible and in UV, the flower shows a uniform light or dark appearance, with the flower centers undistinguished from the petals. VIsible: UV (S8612 1.75mm + UG11 2mm): -- Edited to add a large pano of the whole head at 1500nm. 58 images.

The new Sony SWIR sensor looks really interesting. Capable from at least 400nm to 1700nm. For only about $9000 USD, you can buy one. First saw it here: http://image-sensors-world.blogspot.com/2020/05/sony-unveils-swir-sensors-for.html?m=1 Here is the Sony data and prices: https://www.sony.net/SonyInfo/News/Press/202005/20-036E/

Stefano's thread on solar panels glowing in IR (when you push current through them the "wrong way" rather than shine light on them) occasioned some skepticism from me (since indirect bandgap semiconductors are supposed to make very poor LEDs). It seems that "very poor" is not the same is "you don't get anything at all" because I can reproduce the effect. The equipment was: -TriWave germanium-on-CMOS camera (QE >0 between 350nm and 1600nm, roughly) -Solar panel I ripped out of an old IKEA solar powered lamp -9V battery and alligator clips -1100nm, 1150nm, 1200nm, and 1500nm long pass filters (all from ThorLabs). The first two are blocked to OD4+, the latter two are blocked to OD5+. - f=100mm NIR-AR-coated Thorlabs lens (25mm diameter) The results were as follows. With no filter on the camera at all, and power applied to the solar panel: With the 1100nm long pass: With the 1150nm long pass: I didn't continue on to the 1200 and 1500nm long pass since I'd already lost the signal at this point. It seems pretty clear that most of the signal is below 1150nm (regardless of what graphs on the internet might say...). I put my 980BP10 filter (Thorlabs, naturally, one day I will own their whole catalog and die happy) on the Sony A7S and took a photo: EL-Nikkor 80mm/5.6 F/5.6, ISO10000, 5 min exposure (bulb) Still to try: putting the 1100nm long pass and the 1150nm long pass on my Sony and seeing what I get.

https://medium.com/valence-digital-magazine/say-hello-to-the-worlds-first-handheld-swir-camera-c5432b3a0f3f https://www.ebay.com/itm/800-1600nm-Handheld-SWIR-Smartphone-Compatible-Camera/113858109409?hash=item1a8278dfe1:g:WhEAAOSwRsRdWbbT 128x128 resolution When they hit 320x240 or whatever, I may want one...the TriWave is nice but not portable at all. Incidentally, the website falsely claims that nobody has used germanium for SWIR, when as we know, the TriWave does. I would very much like to know what is going on here. Is there a relationship between the former NoblePeak and Stratio, who makes this new camera?

I found this interesting: http://image-sensors-world.blogspot.com/2019/10/iedm-2019-sony-presents-48mp-all-pixel.html?m=1 In that article, Sony described a new high resolution SWIR sensor using Copper wiring to improve signal. Apparently, SWIR are becoming more popular. This is the quote: "Sony Semiconductor Solutions Corporation We developed a back-illuminated InGaAs image sensor with 1280 x 1040 pixels at 5-um pitch by using Cu-Cu hybridization connecting different materials, a III-V InGaAs/InP of photodiode array, and a silicon readout integrated circuit (ROIC). A prototype device showed high sensitivity at visible to SWIR wavelengths and low dark current."

Not sure what this is, but obviously a close relative of black-eyed Susans. This flower continued the trend where the disc flowers of aster family flowers are interesting in SWIR. Visible The colors are not quite true on this, because I did an autotone in PS, but they came out so nice that I kept it anyway. The yellow parts of the flower stayed yellow, though. UV-A This is HDR with 4 images. WB off PTFE, didn't monkey with the colors much beyond what the HDR did to it. SWIR A large panorama with 164 images.

This is a cultivar, found growing in a bush. It matches the existing UV signature for that species on the site here. (The only other thing it could be is dwarf cinquefoil, but the leaves don't match. Or, I suppose, some other cinquefoil that we don't have a record of on the site yet.) Of note, the SWIR image showed some interesting effects on the anthers(?) around the center of the flower. (I am not confident of my botanical vocabulary here.) Visible and UV-A photos were taken with the Resolve 60mm lens on my old NEX-7 camera (which is APS-C and therefore is better covered by the small image circle of the Resolve lens). SWIR was with the TriWave camera. I did not record exposure info. Visible (BG38 2mm+DB850 stack) UV (330WB80 filter) This image is an HDR made from 4 exposures, because those petals were very very dark. SWIR (Thorlabs 1500nm long pass filter, and the camera cuts off at 1600nm) This is a pano (as all my SWIR pics are now, since that's the only way to get a decent resolution). I also oversharpened it, but oh well.

A classic sunflower. The SWIR is the major contribution here, because many sunflowers have been imaged before on this forum. I made a 530 image panorama to get adequate resolution, and the results look nice. It took all night to stitch the images, and I went through 5 software packages before I found one that didn't get bogged down by the sheer number of images involved. Most stitching programs are geared toward a small number of images with a large number of pixels, rather than the opposite situation, which is what I have with the TriWave! Vis sunshine Resolve 60mm lens, F8 iso640 0.04" (DB850+S8612 1.75mm) UV sunshine Resolve 60mm lens, F8 iso2500 2" Vis sunshine Resolve 60mm lens, F8 iso640 0.04" (DB850+S8612 1.75mm) UV sunshine Resolve 60mm lens, F8 iso2500 2" UVIVF ConvoyS2+ Sony FE 55mm lens, F8 iso1000 30" IRG sunshine Resolve 60mm lens, F8 iso400 0.005" (DB850+Tiffen #12) Near infrared (830-870nm) sunshine Resolve 60mm lens, F8 iso400 0.05" (DB850+Hoya R72) SWIR (1500-1600nm) halogen Thorlabs 50mm achromatic doublet, F10-ish, not sure how to quantify the rest of the exposure info. Thorlabs 1500nm long pass filter. 534 image panorama stitched with Panorama Stitcher, a Mac app available in the Mac App Store. This was the program that finally worked after trying Hugin, PTGui, Photoshop CS6, Panoweaver, and Autopano Giga. Autopano Giga's free trial actually worked, but when I went to buy it, I discovered that Kolor, the company that made it, had been bought by GOPro, which then discontinued the product! With no way to unlock the software, I had to find another program. Due to stitching errors near the edges, I was forced to crop this more than I would have liked. The results are still pretty nice, though, and I found that the sunflower (as with other members of the aster family) has a dark center in the SWIR 1500-1600nm band, despite being pretty uniformly white in the 850nm NIR range.

I tried a St. John's Wort. The UV was mostly for comparison to the SWIR, but it came out rather nicely. What a lovely flower this is in UV! Visible sunshine, Resolve 60mm quartz lens, F16, iso2500, 0.02", DB850 + S8612 1.75mm UV sunshine, Resolve 60mm quartz lens, F16, iso2500, 2", 330WB80 filter SWIR 1500-1600nm pano shot with 50mm Thorlabs SWIR-coated achromatic doublet, stopped down. The filter was a Thorlabs 1500nm long pass. Camera was the TriWave, and currently I have no idea how to quantify the exposure settings.