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Several times on this board, people have mentioned the possibility of a "sound camera" for making images from sound waves. Of necessity, the waves would probably be ultrasound because the diffraction limit really makes things blurry if the wavelength is much beyond the millimeter range. Conventional "B-mode" ultrasound machines do not make passive images the way a camera does, using available sound waves from the environment. Instead they work more like RADAR/SONAR/LiDAR and send out a pulse of ultrasound and use the time-of-flight of the echoes to form an image. While I would eventually be interested in a passive ultrasound camera, I noticed on eBay that the price of conventional ultrasound machines has fallen enormously, and veterinary models (for pregnancy testing of dogs and cats and other farm animals) were in the ballpark of $600 for the most stripped-down models. I decided paying $550 (for used/refurbished) was a reasonable amount to splurge on as a toy. So I bought the DAWEI S0 Portable Veterinary Ultrasound. You may read info about this particular device here, although as I said, I bought mine on ebay. One of many drawbacks of ultrasound as a modality is that, to generate an image, it assumes the speed of sound is constant in all substances, and for a medical ultrasound, not only constant but roughly equal to the speed of sound in water (1500 m/s). So you are restricted to imaging the following things: 1) things similar in density and speed of sound to water 2) there is no (2). See number 1. That leaves you with body parts, stuff made of plastic, most other living or formerly-living things including flowers and fruits/vegetables, and...that's it. You won't be looking inside anything with a hard outer case. On top of that, ultrasound does NOT travel though air (this is why they slap ultrasound jelly all over you at the doctor's office) so you need to either coat the probe in something (water, dish soap, and glycerin all worked pretty well), OR submerge your object in a tank of water. The probe, but not the electronics, is waterproof to 1 meter. So far I have had fun peering at my organs in cross-section — that's another thing, you really have to get used to imagining things in cross-section — and I have bought a little turntable that I can computer-control which should allow me to take multiple images at different angles in a systematic way. The turntable hasn't arrived yet from China. Then I plan to try to do some tomography and make 3D ultrasounds. The frequency is adjustable from 2-5MHz, so it should be possible to do "tri-color" images also. Meanwhile, here we have my middle finger: And inside my finger:

An interesting paper in the current issue of PLOS Biology: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002444 I haven't had time to read it fully yet, but the illustrations look good!

The TriColour technique is probably my favourite way of representing false color in invisible light photos (UV, IR, and theoretically any other band of the EM spectrum). False colors will always be false, but I feel like this technique makes "truer" false colors, as there's a logical meaning behind. Traditionally, this is done by taking three photos of the subject at three different wavelengths. The images must be superimposable, meaning the subject must stay still, the lighting should stay the same, and the images must be taken from the same point of view, otherwise color fringing will occur. This is fine if the conditions above are met, and I have taken some images this way which have little to basically no color defects. For videos, however, things are much different. Normal color sensors have subpixels for red, green and blue, and take the frames at the same time in all spectral bands. Outside the visible spectrum, if such sensors are not available, one has to use different strategies. Method 1 (naive method) The most obvious approach is to use three cameras, as close as possible, with three filters on their lenses, and take the frames at the same time. It would work fine for far away subjects, but at close distances parallax would be obvious. Pros: - simple to implement; Cons: - needs three sensors and three lenses; - parallax at close distances. Method 2: filter wheel I discussed this idea here: a spinning filter wheel is placed in front of the lens, and the setup is timed so that the sensor takes a frame every time a new filter is in place. If done quickly enough, this could allow for TriColour video. The problem is that fringing would be visible for fast-moving objects, and the sensor will have different sensitivities at different wavelengths, so ND filters might be needed. Pros: - only one sensor and one lens are needed; Cons: - difficult to build (the sensor and the filters must be synchronized); - the lens must be corrected for chromatic aberration. Method 3: dichroic mirrors To take three images at the same time at three different wavelengths from the same point of view, dichroic mirrors can be used. They reflect certain wavelengths and transmit others, essentially splitting the image. The biggest downside is that the lens must be either telephoto or strongly retrofocus in design, as the image plane cannot be close to the rear element. As for the retrofocus lens, here's a very raw attempt, at f/8: Pros: - allows for true simultaneous images without parallax; - corrects chromatic aberration (by adjusting the individual sensors); Cons: - requires three sensors; - for wide angle images, the lens must be strongly retrofocus, which makes it difficult to design; - dichroic mirrors in UV are not easily available (maybe interference filters at 45° could be used, although they are usually designed for near perpendicular light beams). A similar technique has been successfully used here. Method 4: dichroic mirrors with image screen This is a possible improvement of the previous method. It's the same camera as before, but the image is first projected onto a screen by a first lens, and then the screen is imaged with a second lens with longer focal length. This way a retrofocus lens is not needed. To increase the brightness of the image, the screen could be made with a microlens array or a Fresnel lens, although I doubt it would work much better. Something similar was used by Andy for his early SWIR experiments: https://www.ultravioletphotography.com/content/index.php?/topic/2112-swir-camera-setup-and-some-pics Pros: - allows for true simultaneous images without parallax; - doesn't need a retrofocus lens; Cons: - requires two lenses; - the sensitivity is likely lower than in the previous method, which is a problem especially for UVB; - the first lens must be corrected for chromatic aberration. To connect multiple sensors, I think a Raspberry Pi or similar could be used. I had other more exotic ideas (like using phosphors excited by different wavelengths), but I don't think they could be practically built. I think method #3 is the most reasonable.

A friend sent me this YouTube link for obtaining IR images with Sony cameras by the use of a magnet! I don't own a Sony camera so can't test. I do wonder what the magnet does for the other components of the camera! https://www.youtube.com/watch?v=2mug6xGPdhY

UV highlights often record non-linearly. I can take a shot and, upon review, the histogram might show exposure peaking near the middle. Add perhaps 1/3 to 2/3 steps more exposure and the histogram is close to or crashing into the right side. This is all done with EL-Nikkor closed down to the same aperture and camera on manual. Light appears the same. Is there something about UV light that causes this? Thanks, Doug A

Not exactly sure how to explain this as I haven't done much experimenting with it, but the other day, I was shooting around in a retail space where they had those blackedout windows, and I noticed through the viewfinder, something seemed different about that dark. It seemed richer, fuller even. The words in this photo are not a reflection, the cars are. The words are a light through the window. This photo might give some notion of what I'm talking about better than just my words and it's what I took. This photo has been heavily processed, but the tones and clarity I could get from this dark reflection seem so different from what I would get in a normal camera. What is this? Is this my eyes playing tricks on me, or is this something to do with spectrums? Is there a name for what is happening so I might research it further? Not sure if it's related, but I'm currently messing with a reflection photo in a puddle that was made via a shadow, and it's sorta doing the same thing having a richer dark tone.

So I have researched some alternative color arrays that were used throughout time, and I found out that Kodak apparently made two DSLRs with a CYYM color array. Kodak DCS 620x and 720x. Does anyone know anything about these cameras? I looked at eBay and couldn't even find one, I wonder if they're affordable and if one could convert them to full spectrum. They're like 3mp but would be fun to play with regardless.

I have recently joined what seems to be a new wave of people buying the Sony DSC-F828 2003 point and shoot camera, mostly due to its one of a kind sensor and extremely easy full spectrum conversion. I have been very curious what UV looks like with this camera, given its RGBE sensor. I have only obtained a fitting magnet to flip out the hot mirror filter last evening so there was no time to do UV under natural light. I got to do it now, though. The image is in full resolution, so feel free to click and enlarge. ZWB2+QB39 Tangsinuo stack 3s exposure, ISO 64, f/2.5 These flowers are UV yellow, yellow in real life as well. They're about as UV yellow as gerberas or dandelions. Here they are a very desaturated shade of orange. I think it's due to the fact that the Zeiss T* Vario-Sonnar 2-2.8/7.1-51 zoom lens does not pass much UV at all. That is to be expected, but still a shame, since this sensor could have unlocked a lot more UV false color, given its 4 color channels as opposed to the usual three. Last observation: flipping out the hot mirror seems to make the image only marginally brighter, meaning the hot mirror either does not block much UV at all or the lens passes so little most of what does pass is around a wavelength the hot mirror was not designed to block. Either way, I am happy I have this camera now, the IR results have been a lot less underwhelming, and even the normal visible photos have an interesting look to them, very much unlike the images taken by modern cameras. At the risk of sounding like a huge cliche, they do look somewhat film-like color wise. Probably since back then, digital was still considered to be a replacement for slide film (and was designed as such), not a universal best way to record anything.

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 recently found a reasonably-priced MaxMax 8Mp monochrome IR-Vis-UV USB camera with no sensor cover, along with a 25mm quartz lens. I'm thrilled about this, and I'm hoping to use it as a microscope camera using UV light. Does anyone know the lowest wavelength that can be imaged by this camera? No software info came with it. So I tried my standard astrophotography camera software, Sharpcap. It worked! I could adjust exposure speed and choose between file formats and color space. The "color spaces" allowed were MJPG and YUY2. The MJPG format showed severe compression artifacts but YUY2 output looked fairly uncompressed. But there may be better dedicated software for this camera. Does anyone have any experience with this?

The Raspberry Pi HQ camera has shown good results for UV photography. Below a couple of topics in which this camera has been discussed: https://www.ultravioletphotography.com/content/index.php?/topic/3883-raspberry-pi-hq-camera-12mp https://www.ultravioletphotography.com/content/index.php?/topic/4178-uv-safety-warning-reaspberry-pi-hq-affordable-fast-uv-sensitive-sensor Universe Kogaku makes two 6 mm UV lenses, one with a fixed aperture of f/2.8 and the other one with a variable aperture from f/3.5 to f/16. Both lenses cover a Raspberry Pi HQ camera sensor (diagonal of 7.9 mm). The f/2.8 lens covers a 4.8*6.4 mm sensor (diagonal of 8 mm) and the variabile aperture lens covers a 5.2*6.9 mm sensor (diagonal of 8.64 mm). This is the datasheet of the variabile aperture lens: https://www.universeoptics.com/wp-content/uploads/UV0635BCM-1.pdf Also, this lens has a C-mount. These lenses, as the other UV lenses from Universe Kogaku, are not corrected for chromatic aberration. One could rear-mount two 310 nm bandpass filters, to reduce angle-of-incidence effects, if this doesn't degrade image quality too much. One such filter could be this: https://www.edmundoptics.eu/p/10nm-cwl-125mm-dia-hard-coated-od-4-10nm-bandpass-filter/33098/ Of course I'm thinking about a monochrome-converted sensor.

Hello. I was wondering if Foveon X3 sensor greater quantum efficiency in ultraviolet and infrared spectrum? This is unusual sensor technology unlike traditional CMOS utilising 3 layers to capture color instead of Bayer mosaic filter. I imagine in full spectrum mode first layer should sensitive to UV and deeper pixels to infrared. Bayer filter does block a lot of UV and little IR. It can be removed in monochrome conversion but then ability to record color is lost.

I got a Bushnell Trail Camera: B&H Link to set up on the property in order to try to see what lives in the various dens, burrows and holes. My first trial was yesterday and last night. I put the Trail Cam on a tripod and set it out in the back courtyard to see what might show up to visit a ground feeder containing some birdseed. I got some bird photos. And I got a few IR photos of some rodent. Bottom line: the Trail Cam works!!! The Trail Cam shoots Camera (stills), Video and Hybrid (don't know what that is yet). At night it shoots Infrared with "no-glow" illumination choices of Low, Fast Motion and Long Range. Coyotes, Look Out!! I'm gonna see you prowling around!! There are 32 megapixels. Images and video is stored on a typical SD card. Set up is totally easy, but there is a small learning curve for the settings. The examples posted here were made with a Medium image size, Long Range illumination setting, Auto sensor level, 24 Hour mode with 1 sec delay between shots. Given that the Trail Cam is motion triggered, I did get a few shots of nothing which were probably due to breezes or instability? The Medium daylight jpgs are enormous at 7552 x 4248 pixels. The Medium Infrared jpgs are smaller at 3840 x 2160 pixels. Some daylight photos had minor motion blur. The trail cam is usually shown tied to a tree (straps were included). So it probably was slightly unstable on the tripod? I will weight the center next time. I wanted to use it with a tripod because we really do not have many trees around here. (Well, ok, there is obviously one tree in this courtyard. La! But I really want to try to work with a tripod for the Trail Cam.) Photos are date- and time-stamped with a temperature recording. The menu lets you add coordinates too. The photos are very wide-angle with current settings. VISIBLE: Scrub Jay at Feeder Box Afternoon light, no shadows. The sun was hitting the trail cam, so it seems to have recorded a higher temp than it actually was. No edits. 25% downsize to 1888 x 1062. VISIBLE: Scrub Jay in Flight Morning light with shadows. There's another Scrub Jay sitting just behind the feeder box. That's a collared dove to the right. A mated pair visits regularly. Note that the temp is below freezing. No edits. 25% downsize to 1888 x 1062. INFRARED: Nocturnal Rodent I'll show one uncropped so you can see the general appearance. Evening after dark, 6:29:00 PM. No edits. 25% downsize to 1920 x 1080. The other IR evening photos are shown with big crop but no resize. 6:29:04 PM 6:29:19 PM 6:29:30 PM 6:29:52 PM The critter came back the following morning. I think it is the same one ?? 5:31:51 AM 6:18:26 AM See my scary IR-glowing eyes. I am a fierce little guy! 6:21:57 AM These IR photos are, of course, not quite up to our photographic standards. But I'm thrilled anyway to have the Trail Cam with IR night-time capabilities. It will be fascinating to catch a view of the wild creatures which live around here. SIDE NOTE: Identification of Nocturnal Rodent I went out and measured the stone where this Rodent liked to perch. Here is a crop showing that measurement. We can get a fairly reasonable estimation of the Rodent's size. Rodent's tail is probably about as long as its body (excluding head), but not longer. The body plus head seems to be about 5-6" = 12.7-15.3 cm in length. The ears are fairly large in relationship to the head. (See above 6:18:26 PM). Added later: I also estimated the tail to be about 4" = 10 cm in length. Field Guide Reference: Mammals of North America by Kays & Wilson, Princeton Field Guides, Princeton University Press, 2002. I mostly know what this Rodent is not.[*] By process of elimination, my best guess is that the Rodent is some kind of Deermouse because of the relatively large size of the ears compared to the head. WRT the field guide, see N. American Deermouse pg 114, Cactus Dm pg 118, Brush Dm pg 120. [*] The rodent is not a Pack Rat (Woodrat), Kangaroo Rat, Rattus, Shrew, Pocket Mouse, Vole, Jumping Mouse, Cotton Rat, Grasshopper Mouse nor is it any one of the Tiny Mice (House Mouse and others). This leaves the Deermouse types to choose from. But, hey, I could be way wrong!! You can't be afraid to be wrong in this world else you'll have a very boring life and never learn much.

Peterborough UK River Nene Embankment 'Willow Tree' IR images taken on a frosty / sunny day, 17 January 2023 with a 'full spectrum converted' Leica T (Type 701) / Leica TL 11-23mm / URTH 720nm IR filter . Full spectrum conversion by Alan Burch, "Infra Red and Full Spectrum Camera Conversions" IOW UK. The Leica T is a 'great unloved' Leica APS-C ICL camera partly because its AF can be too slow – but in manual focus mode, with magnified 'live view' it's fine. The T does not have an integral live view EVF; it relies on a hot-shoe fitting accessory EVF – made by Epson but 'badge engineered' Leica'. The long discontinued 16.2MP Leica T (only available s/h) is the cheapest ICL Leica APS-C camera. My first pix posted to the forum. BW, dunk

https://news.panasonic.com/global/press/en230126-2

I'm thinking of retooling for the new year. Thinking of picking up an A6000 full spectrum from life pixel and a Badder U possibly from B&H. I know the camera is low end but I'm hoping it's a step up from my really low end Nex 5n. I've seen a user or two on here with the A6000 so it seems to work. Anyone use this or have any comment? I'm also hoping the Baader U is a step up in transmission. I have a La La U by UVIROptics but I think its best transmission is like 30% at 360nm or something. Where is the best place to get a Baader U? For photography I read here that it works best threads first. How thick is the Baader U with it's brass body? Thanks

A vendor I have worked with in the past asked me if I wanted my 50R evaluated for a debayering. He offered a discount on the conversion if it was a go, which I suspect it will be. I am all set for converted cameras, but thought I would share the offer. PM me if you are interested. I have no financial interest, just helping out.

Here's a video I shot a few months ago when I first got my Samsung Galaxy Z-Flip3 smartphone. I held up a 760nm cut-on filter over the lens and was surprised how well it turned out. I finally created a Vimeo account to post the occasional video here so this one is my first attempt. I didn't make any adjustments to the camera settings, it automatically pops into night mode when the scene gets dark enough. I only edited the video to reduce the bitrate so the filesize would be better for online. There is a prominent hotspot in the IR portion of the video. If you're wondering why the foreground grass looks dark in IR it's fake grass, some sort of vinyl plastic. Here's a few stills taken at the same location recently using the same smartphone & filter. I monochromed them and reduced to 2000 pixels for posting here. The last one was taken in the shade and could barely be handheld due to a slow exposure of 1/17 second. The quality isn't superb but remember these were taken with a lens smaller than the button on your shirt. The gear. The little 27mm filter is about the right size to allow a wide angle shot from the phonecam's tiny lens. 720 and 760nm filters worked best. 800nm was getting too dark for handheld shots. The IR only works in bright daylight but the little filter makes a nice accessory for this smartphone.

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. I was thinking about UVC photography, and wondered if the Bayer filter dyes would fluoresce and cause problems. Then I realized this would not be a problem but a solution. If a layer of material on the sensor would fluoresce in UVC, then the photocells would record the pattern of light. What if we could coat the sensor (preferably de-bayered) with a thin layer of phosphors? Maybe some kind of paint, applied in very thin layers (preferably a mix with white fluorescence, if the sensor still has its Bayer matrix). Any irregularities in layer thickness could be fixed using the astrophotography technique of applying "flats" . If the layer would be relatively opaque to visible light, then the sensor would only record UV fluorescence, not visible light, so with care we could dispense with UV-pass filters! This technique is of course a variation of a standard technique for visualizing things like x-rays. I wonder if maybe we could figure out a simple variation for our application.

Hi there. After using a modified D70 (720nm) for 13 years, I moved to the Z system and finally decided to also get a modified Z camera to join my regular Z9/Z6II pair. I squinted at the Primaluce Z5 for a while (and read the thread about it here), but they wouldn't come down with their price, so I took advantage of the current cashback rebates, got one new and had it modified for full spectrum by Makario. I'm aiming for IR landscape photography but still chose full spectrum to later experiment with other uses. Using an screw-on 720nm filter for now. As it is widely known, the Z5 (and probably all the other Z cameras as well) won't measure custom WB from an infrared image, as it's apparently doing a "sanity check" on the resulting values and concludes there's something wrong with the measurement. Of course, I tried to trick it into accepting something anyway. Among the things I tried: - putting a D70 jpg onto the card to measure from - modifying a Z5 jpg with experimental WB values via exiftool and measuring from that The D70 is not accepted, and it also seems that if the values in the image for PRE are too extreme (like >2), the camera will not reject them for PRE measurement use, but the PRE setting remains unchanged anyway. Even then I managed to get some wild results, but all are resulting in either too green or too red or too purple images. I will of course set the white balance in RAW processing later, but I'd like to see a reasonable preview of the brightness values in the viewfinder. The closest I've got now is setting the value to 2500K and tint all the way to green, then set a monochrome picture profile. I also contacted the Nikon support, which has been very helpful in other occasions including resulting in actual firmware changes for bug fixes, and asked for a way to set white balance off any source image for artistic freedom, infrared imaging, and colored lighting situations. I would encourage anyone "suffering" from the same problem to do this, too. Did anyone have more success or try other ideas to trick a Z camera into better WB preview? Again, I'm aiming for 720nm in daylight currently. Maik

If anybody is interested this is what I can do with Fujifilm GFX 50R mono + Fujinon GF 50/3.5 (modern, non-UV lens) on a foggy day (I only have free time on weekends, and I have no luck to weather, fog, tmperature around freezing, very short days - 52 degrees North). ISO fixed at 100. F usually 11-16. T from 20s to 2 minutes. Attaching almost full frames and 100% crops.

Kolari offers an optional anti-reflective coating on their replacement sensor covers for camera conversions. They state that this coating reduces hotspots in IR photography and they provide some technical background to support this. They state that hotspots may originate in the lens or outside of it (as mentioned in UVP's technical zone), and provide some discussion of the factors affecting hotspots: Kolari hotspot article One reviewer states that this coating reduced hotspots considerably in his tests: Edward Dozier article Lifepixel disagrees about the source of hotspots (always from the lens they say) and claims that the anti-reflective coating (their own sample and one from 'a competitor') doesn't help any: Lifepixel article (While the photos in the article were taken at f/22, in the comments they discuss their results at larger and more reasonable apertures.) So we have two vendors who disagree on this subject, with one vendor criticizing the product promoted by the other. While the article by Kolari appears to be more comprehensive on the technical side, I don't have the technical chops to evaluate this situation. Has anyone tried the Kolari anti-reflective coating on their camera conversion? Any comments on this issue from a technical standpoint? Thanks, Bill

Thinking about converting a small camera to full spectrum. Camera can be converted without disassembly. If I don't replace the UV/IR filter in front of the sensor, the native camera lenses won't focus to infinity. The lenses probably don't work well with UV, but it would be nice to use them with IR. The original glass is .6mm x 12.6mm x 13.1 mm. Where can I order a glass sensor cover that doesn't impede UV light? Thanks, Doug A

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

After a long research I've decided that I will buy another 50R used body and convert it to full spectrum and remove CFA/bayer Filter. This shoudl eb the cheapest option IMHO to get very UV sensitive camera... I'm still not 100% sure about mono conversion - I've read in many places that R, G, B filters on pixel are very opaque to UV, even with full spectrum conversion. On one hand I gain a lot of sensitivity but on another I loose chance to see the famous "UV green" - so I'm 70% sure that I will go BB+mono and 30% sure that only BB. - If I choose just FS/BB then I already have a guy who will convert it for me in Poland (hhe did all my cameras excluding D600 mono) - But If I want mono - do you know any company or a guy who can comvert it within European Union? (I want to avoid sending outside and receiving because of customs etc.) I can't ask the guy who did that for my D600 because it was a pure experiment (I would call it brute force) and it is OK but parts of CFA were not removed at the sides etc.