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I had an odd result in a test recently. While doing some fluorescence imaging, I got something which looked like red specular reflection (the camera was a stock Canon with the internal filters still in place). I realised that I'd forgotten to put a long pass filter on the camera lens, but thought it may have been down to some red contamination from the light source. However this was where it got a bit weird. If I put a 420nm long pass filter on the lens, the red specular reflection disappeared. If is was red light just reflecting from the subject this would not be removed using the long pass filter. It turns out that this red reflection is due to the UV. The internal filter setup in my Canon 5DSR doesn't block all the UV - there is a double peak with quite a large transmission at around 370nm. Given the sensitivity of the sensor at that wavelength, this looks red in the image. I've done quite a lot of work on this now to try and understand it a bit more, and have seen the same effect with my Canon 6D, which makes me think that it's not just an issue with the 5DSR. I'll share my findings on here, when I've made the graphs and pictures a bit more neat and tidy. Has anyone seen this type of effect before?

I’ve been wanting to get started in UV and IR video capture for a project combining the visual spectrum with IR. I was, rightfully, directed to start in the IR field first since it’s a bit easier of a starting point. I stumbled across an interesting video where a fellow took a $50 action camera, removed the lens and hacked it (melted a large enough hole) so as to attach a c-mount adapter for more flexibility. Seemed like a great idea. It got me thinking about options. While the action cam idea was great, it’s not as flexible as I’d need since it will require a HDMI capture board to get realtime input. From what I’m seeing at this point, it would take either a pretty costly multi-input capture board or some MacGyver’ing of multiple single capture cards via a bitcoin mining riser card (doable, but a lot of work and extra energy consumption). It dawned on me that an even cleaner option could be possible: Find a USB capable cam or webcam that has a sufficiently sophisticated CCD that will extend a good distance up into the IR portion of the spectrum. Does anyone have any recommendations of what to look for as far as a webcam or some such USB capable camera? I’d like to go as deeply into IR as is feasible without initially get into >$200-500+ cameras (if possible), especially since this first round for this buildout is going to also require a lot of software engineering too. I’m looking to integrate 2 IR cameras + 2 visual spectrum cameras (all the same kind, just the IR would be hacked) so as to generate stereo images within a VR/AR (Augmented Reality) output headset. I suspect I may also need to buy some lenses to only capture IR as well for the IR hacked cams - so I’ll probably need to affix an adapter to accept such lenses. Any thoughts or ideas would be fantastic!

There is a little buzz around the new Sony 3 layer organic sensor. In that its similar, yet different than the Sigma Foveon sensor. Sony has a top Organic quinacridone layer that captures the green signal then uses a traditional back side illuminated sensor with depth to detect the blue (top of silicon) and red channel (lower level of silicon) information. Why this is special for UV photography is that top Organic layer, it is extremely sensitive to UV than anything else I have seen. Imagine 80% quantum efficiency in UVB, compared to less than 5% with our current sensors. Where the UV signal washes out the IR sinal. This would be very fun. Down side is that false colors would be very green with little blue and no red. So expect a monochrome image.

Kolari has just released their tear down of the Panasonic S1R. https://kolarivision.com/the-panasonic-s1r-disassembly-and-teardown/ Not tested yet, but it does look like you pay for the excellent build quality. I hope it doesn't have the IR shutter monitor problem. I am excited by the Panasonic S1H. It's basically a million dollars. As I could no way afford it. But has most of the check boxes hit. Contrast detect sensor, so no banding due to phase contrast pixels. Excellent dual gain ISO. A cooled sensor! This would be great for long exposure settings. High resolution shot mode.

Lens Rentals has Kolari IR converted cameras available for rent. But sadly no full spectrum converted cameras. Which to me seems odd, as there is more freedom to use any filter. Please everyone and anyone email: support at lensrentals.com And let them know you maybe interested in a rental. I emailed and they said there purchasing department may consider it. So if there is more interest, I see this maybe happening. I would like to compare a Sony A7S, Panasonic S1 and new S1H with cooled sensor.

The Samsung smart phone sensor has been officially announced. The specification that interested me is that the pixels are 0.8um in size. That is 800nm! I wonder what that means for IR detection.

https://www.youtube.com/watch?v=reeLH_UYh7U https://sunscreenr.com/ watching above links it appears the prototype had a electronic viewfinder? but the final product is plugged into a mini usb socket on the phone and uses phone screen as viewfinder.

Finally, a successful UV art portrait lens! I attached a ~1930's Emil Busch Neokino 120mm f2.1 petzval-design cinema projection lens to a M65 helicoid with a 62.5mm to M65 RafCamera adapter, and mounted it to a full-spectrum 5Dmk2. I drilled a hole into a Pentacon Six lens backcap that happened to snap onto the front of the lens, and superglued a 62-to-77mm step-up ring (maybe 58mm? forgot), creating a filter holder. I stacked a 77mm UG-11 and S8612 for ultraviolet. As highlighted in previous posts, this lens has phenomenal UV performance, despite being a fast telephoto. The petzval design gives beautiful bokeh and glowing highlights, although the dated optics don't give the sharpest image in town. Since the goal was art, not technical perfection, I wasn't too bothered by this. Model: James Gray. You might notice in some of the waterside photos he has a strange dark ring over his left eye. I puzzled over this for a while before figuring it out. I was wearing sunblock on the day, but he wasn't. When he looked through my LCD magnifier to see some of the images, he inadvertently acquired the sunblock that had rubbed off my face onto the eyepiece. Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Ultraviolet, Neokino 120mm f2.1 with UG-11 + S8612 Visible, Mitakon 85mm f1.2 Infrared + visible, medium-format Pentacon Six Biometar 80mm f2.8 with tilt-shift adapter Infrared (720nm), 140mm f1.8 soviet projection lens Visible, 50mm f1.2 soviet projection lens Infrared (850nm), 140mm f1.8 soviet projection lens Visible, Helios 40 (85mm f1.5) Infrared + visible, 140mm f1.8 soviet projection lens Infrared + visible, Mitakon 85mm f1.2 Visible, 50mm f1.2 soviet projection lens Infrared (850nm), 140mm f1.8 soviet projection lens Infrared + visible, Arsat 30mm medium-format fisheye lens on tilt-shift adapter

These were shot back in August with a newly converted Sony a7R with a vintage 50mm f1.8 Nikkor + yellow #12 filter, then processed in Sony EDIT, for Aerochrome colors. I noticed some minor dust particles in this conversion, and ended up sending the camera back for a re-do. I think I was spoiled by the Sigma, with it's removable hot-mirror filter, but I guess some dust particles are to be expected, even with Class 100 clean room facilities. If the upcoming ff Sigma (leica mount version) continues to incorporate the same user-removable hot-mirror design, I may consider that in the future. In the meantime, I'm looking forward to the a7R when it arrives. Same size as the m43 Olympus M1 Admin: edited title to reflect this is about a Sony, not Sigma, camera.

During a recent shoot I briefly swapped on some UV lenses for some experimental photos. While the shutter speeds make it incredibly difficult to get a clear image, the resulting images have a quite interesting look. I used a Zeiss Biotar 2/58 and a Kodak Ektanar 2.8/127 triplet projection lens +UG11/BG39. The lens choice was aimed primarily at creative rendering. This was before I got my Meyer Diaplan 2.8/150 and ISCO 2.1/120, so no shots with those ones. Next time. Model: Damien Sato Zeiss Biotar 2/58 Zeiss Biotar 2/58 Zeiss Biotar 2/58 Zeiss Biotar 2/58 Kodak Ektanar 2.8/127 Kodak Ektanar 2.8/127 projection

A few shots from out recent Alps visit, all taken on my Monochrome EOS 5DSR and using a 17-40mm lens and Heliopan RG715 filter.

Good evening, I finally received the second part of my filter system based on a U340 2mm filter and a S8612 2mm filter, both in 82mm diameter. This way, I was able to shoot in ultraviolet with my Tokina 21mm F/3.8 and perform architectural UV pictures. I share 4 pictures taken the last week, during a very cloudy day. The UV rate was really low, implying long exposure shots. Each picture was shot with the same EXIFs : 21mm, F/8, 200iso, 30s. The UV effect is the most visible on the windows of the buildings that become darker. For the rest, the global tint is warm and "heavy". The choice of ultraviolet here is only pictorial, I am waiting for spring now to try real landscape photography using wide angle with this technique.

Well I now have a serious learning curve ahead of me. Given my interest in the technical side of skin imaging, and especially the UV imaging I decided to jump in with both feet. I've bought a MaxMax Monochrome conversion for my spare Eos 5DSR. So this will go alongside my un-modified 5DSR so I can do a proper comparison of the two as and when the need arises. Paired with my Asahi Ultra Achromatic 85mm lens this monochrome conversion should be excellent for my work on imaging sunscreens (given the enhanced UV sensitivity from removing the Bayer filter, and where I don't need any colour). Just unpacked so no sample images yet. and I'm going to have to get used to not seeing what I'm photographing again when it comes to opaque filters.

Track Hoe. 850nm Infrared (Schott RG850 filter) , D7000 UV/IR, 18-55mm VR lens.

Good afternoon, After my exhibition, I spend some days in the Azores and in Lisbon. While I only shot in infrared in the Azores, I decided to try street photography in ultraviolet in Lisbon. the widest lens I have for UV photography is 35mm, which seems to be a good focal for the street. Finally, I made a series of 16 pictures divided 8 diptychs. I show you half of them. About the gear, I used a Canon 6D full-spectrum, a Soligor 35mm F/3.5 and a Kolari UV filter. EXIFs were adjusted to allow handheld shooting : 35mm, between 4000iso to 6400iso, F/5.6, between 1/40s to 1/80s. About processing, I worked on the channel mixer the same way than for infrared photography to recover a blue sky. Thanks!

I need a bit of help please folks. I'm looking for a reference for a paper I'm preparing which specifically pulls out the relative sensitivity of a typical bare camera sensor to UV and IR. I'm wanting to write a few lines on the need for complete IR blocking when doing UV reflectance imaging, so it would be great to be able to quantify the degree of the problem. Thanks.

Good afternoon! I have finally achieved a good portrait with studio strobe : here the Broncolor Pulso G 3200J. I was so surprised by the UV power delivered that the final RAW was overexposed... Gear : Canon 6D FS + Nikon EL 105mm + Kolari UV filter EXIF : 105mm, F/5.6, 1600iso, 1/100s. I am pretty sure I could have reached F/8 and 800iso in this configuration. The focus is not perfect, but for the first test I am happy with this result. I will do better the next time .

I was checking on recent publications by Adrian Dyer's group and I came across this: Garcia et al 2015 http://journals.plos...al.pone.0125817 Make your self a cup of coffee, or something stronger before you start it as it will make your head hurt. It compares, in the visible region only, a normal DSLR with a multispectral camera with 128 channels. I have no idea how much that costs or whether it would work for UV but it might solve my never ending question of what our false UV colours mean and if they really do relate to wavelength or are just clever artifacts of the RGB dyes and the white balancing process. Cheers, Dave

Hello, some new samples with modified Nikon D810 and 720nm filter. Lenses are Nikkor 17-35mm and 80-400mm new version. No problem with naked sensor. And very good results !

Hello ! Some very recent samples with my D800 + Hoya 720nm. No autofocus problem with nacked sensor :) . Taken with nikkor 17-35mm and 80-400mm last model.

Shane, this statemet of yours gave me a push to finish my severely delayed experiments, which I started many moons ago. Thank you! I finally have semi-functional NEX-5N with "de-bayered" sensor (CFA removed). Over past few days I have been testing and comparing my NEX-5N (monochrom) and NEX-6 (full-spectrum) under different conditions (clear sky, overcast) and with different objects (urban landscape, flowers) in order to access the exposure difference between the two. I used both quartz singlet and UV-capable enlarger lens with Baader-U2 filter. Internet sources (not SONY!) suggest that both cameras use the same sensor IMX080, but I have no way to confirm that. Nonetheless, while shooting full-spectrum modified NEX-5N amd NEX-6 in the past, I have not noticed any considerable difference in UV response between the two. Therefore, I hope that my comparison is rather informative. After comparing the NEX-5N (monochrom) and NEX-6 (full-spectrum) I can say that the increase in UV sensitivity for the monochrome camera will be about 5-6 times more, or 500%-600%, or 2.25-2.5 EV (depending on the conditions, and the quirks of the RAW processing software). My findings, thus, agree with what Shane wrote in his post quoted above, and with this statement of Dan from MaxMax - "Our UV-VIS-IR cameras with the CFA have about 1/6 the UV sensitivity of monochrome UV cameras." (see here: http://www.maxmax.com/our_solution.htm). Unfortunately, I have no means to properly analyse the information preserved in RAW files, and have to rely on the files (and histograms) produced after the RAW conversion. This is what I did: I opened RAW files using same exact software, set WB separately for "full-spectrum" and for "monochrom" cameras, de-saturated the shots and then compared the histograms. I know it is rather crude, but the RAW converters I have are not designed to properly "understand" pictures taken with modified cameras in UV. Therefore, you must treat this information with caution. Also, if anyone wants to analyse RAW files themselves using specialized software, I can provide such - just ask here. And now, two example shots. Both taken at the same time (with few minutes interval), under the same lighting condition (sunny clear day), same lens, same aperture, same ISO. Please note that histograms presented in the pictures are based on the shown processed and cropped TIFF files, not on the RAW files. Nothing was adjusted in the files. Difference in contrast you can see is caused by the difference in acquisition of information by R, G and B sensils between sensors with and without CFA. NEX-6 (full spectrum) - shutter speed = 0.6 second http://www.holovachov.com/img/s6/v134/p51681238.jpg NEX-5N (monochrom) - shutter speed = 0.1 second http://www.holovachov.com/img/s6/v142/p462520787.jpg

This might help someone ? It was posted on another forum. http://www.lensrentals.com/blog/2014/06/the-glass-in-the-path-sensor-stacks-and-adapted-lenses Cheers Col

Comment by nfoto (Admin): This topic is established as a placeholder for the various technically orientated post in the Felicia thread here http://www.ultraviol...ible-and-uv-a/. To achieve a continuity in the thread, I've taken the liberty of copying the second and third post in that thread into this one. Here is the comment by colin on Igoriginal's Felicia images. Very nice images & processing Iggy. I like the highlight of the petal damage here too. How have you controlled the excess UV/Blue from the S8612 filter in the Visible shot Please ? Col

ADMIN NOTE: I have split Dave's question off into its own thread because it is interesting. I think the discussion will be useful. We need some facts - and any relevant user experiences. Please do stick to the Diffraction topic rather than veering off into which cameras are better for UV. ******** Hi Bjørn, Many moons ago you told me I would probably one day want to get a Nikon to put my UV-Nikkor on to get infinity focus. Since you use both APS-C (D3200) and Full frame (D600) I wondered what the trade off was in using the APS-C sensor, does the increased risk of diffraction leading to softer images restrict what you can do with the D3200? I would look at the D7100 versus the D610. Cheers, Dave

Hi Everyone I have tried & cried with my DIY efforts to convert my Sigma dSLR to UV capable photography. I have another Sigma dSLR coming that I don't want to kill ! Who do you trust to convert your dSLR to UV capable photography, Please ? I have got so close to succeeding in the swapping of the sensors cover glass to quartz, that the last try I had a slight slip-up in cleaning, that I damaged a gold wire connection in the sensor, before finally placing the quartz over the sensor. Do I continue being brave & try again to convert this latest camera or trust the work to another ?? Cheers Col