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Some of us have been experimenting with the Lee Scuba Blue 729 filter combined with KG3 or GRB3 which gives almost identical results to the Kolari IR Chrome filter. However, it would be nice to have both filters made of glass instead of having to use the Lee 729 I was surprised to see that a seller on AliExpress is now selling a stack of 2 glass filters: QB3 & GRB3 https://www.aliexpress.com/item/1005004024273274.html QB3 is a Chinese equivalent for Schott BG3 Has anyone here tried that combination? The last product picture even shows a camera with the IR Chrome filter on it so it's obviously intended to serve the same purpose. The transmission charts for QB3 and Schott BG3 show they're quite a bit lower in the spectrum though, peaking below 400nm.

White balance on white pvc card Little WB correction on camera to more reds. Some colors retouch in pp (forgot to retouch the cyan in the sky to more blue)

Hi. First shot with the Lee #172 lagoon blue + chinese GRB3 at the end of the day with a weak sunlight. SOOC (panasonic Gf3 full spect conversion by myself)...WB to auto but corrected to yellow/reds. For me it was surprisingly good....what´s your opinion?

I bought a 340BP10 and a 300BP10 bandpass filters on eBay from here. The seller measured the 300 nm filter and it actually peaked at 315 nm. Usual equipment, full-spectrum Canon EOS M and Soligor 35 mm f/3.5. The filters are tiny, so the only way to mount them was on the rear of the lens. I didn't use putty, I instead built a "holder" around them and they press fit my Soligor perfectly. No residues, quick mounting/removal, perfect. I first tried the 340 nm filter. I first put my usual UV-pass filter stack on the lens, ZWB2 (2 mm) + Chinese BG39 (2 mm), and quickly realized the "BG39" attenuates strongly at 340 nm, so I removed it. The ZWB2 filter was almost completely transparent, and I left it on the lens just in case. It looks like the filter has a good-enough blocking to be used alone, and that surprised me a bit. I had a UV in-camera white balance, thus the strong green cast typical below 350 nm. f/(?(either 4 or 8)), ISO 100, 60.1 s exposure f/(?(either 4 or 8)), ISO 12800, 1/8 s exposure Glass begins to darken. I then just took monochrome images, as there isn't much color information anyway. f/(4?), ISO 100, 30 s exposure. Brightness lifted in PN, and then image converted to B&W using the red channel only (raw). Resting on the glass is my ZWB2 filter, on the left is the dark Chinese BG39. My hand. f/(4?), ISO 100, 30 s exposure I then tried with my 315 nm bandpass filter, and I didn't get what I expected. I used it with the ZWB2 filter (it should transmit some there, as it should behave similarly to U-360/UG1, see graph below), and I also used it alone. My Soligor should transmit some there too: https://www.ultravio...ligor-35mm-f35/ UG1 and U-360 transmission (2 mm): What I got was this: f/(4?), ISO 3200, 1/2 s exposure. Everything is soft. I can show other examples, but they are all like this. Further testing showed a significant IR leak. In fact, the image seems to be mostly if not all IR. The next image was taken with a R72 on the lens (and the filter on the rear): f/(4?), ISO 12800, 1/8 s exposure. I don't know what causes this. Is it the filter? Or the lens? Or even the camera? If my camera allows it, I should see something at 315 nm with this filter and the Soligor. But even the infrared leak image is soft. I did clean both filters with a window cleaning spray and a "silicone glaze" as they were a bit dirty. Is it possible that some of it went inside?

I've recently bought Fuji GFX 50R - I *LOVE* it. Its colors and 400 dynamic range option are just amazing! I only have Fujinon GF 50/3.5 "pancake" and it is great. I also have M42->GFX and Nikon-F->GFX adapters and Nikon lenses work quite good with medium to very-very-very huge vignetting. My best finders are 55/1.2 AI which has almost no vignetting, same 135/2 AI-s and (wow) 20/3.5 Ai (heavy vingetting but not just cut-off circle as in almost all wide lenses) - that gives quite usable 16/2.8 equivalent on 44x33 mm sensor. Now the question - I was thinking that I will convert it to BroadBand/FullSpectrum immediatelly - but I just figured out it will probably be my main camera now (again, I love it), so the question is - are there ANY UV/IR cut filters (can be very expensive, doesn't matter) that will revert it back to a normal usable visual only camera? (Can also be vis + UV because UV does not break anything when used with vis, its just too weak). I want to EFFECTIVELY cut off all IR in a way similar to original sensor IR cut-off works. S8612 is not good because it gives bluish hint - something like SEU that has straight edge cut-off (very sharp almost vertical) at 700 or 720 nm, or any other filter that will CUT all IR and *NO* visible. Anybody have BB/FS Fuji GFX 50R and can share photos made with IR/UV cut filter? I just don't want to loose ability to use it 100% normally - and I don't mean Hoya UV/IR cut or Marumi UV/IR cut - they cut IR indeed, but not perfectly - I can see pink/red/violet hue on all photos made on my FS Nikons - they definitely cut some or even most IR, but not all - photos aren't correctly colored, autho white balance is no longer OK.

I see on UVR Optics that the Andrea U replacement filter is soon to be released. Any thoughts?

Hello. In the first tests with the Lee #729 I didn't get the aerochrome sooc effect :( ....I don't know why! maybe it has to do with the white balance of the camera (I've tried many wb settings without success). So I decided to combine the #729, which I placed between the sensor and the lens mount, with other color filters. Using Kenko ya3 I got this beautiful and vibrant goldie effect by messing with the channel mixer and switching channels.... The day is cloudy and dusty from North Africa

Hi. After some ideias i´ve made my own filter holder to test the whole swatchbook .....(i´m kidding ...they are many ). Thanks to @dabateman for the suggestion. I have cut an old sony teleconverter to get the 37mm thread....then glued the 49mm-52mm step up ring on it to give me the possibility of use another filter on the system (chinese GRB3). I made two cuts in the 37mm filter(sony)to fit the filters slider. The filter slider was made of black cardboard. Here some pics of it.

Hi everyone. I finally managed to find a Lee swatchbook in Portugal to run some tests trying to digitally achieve the famous Aerochrome effect. I use the Olympus 14-42 lens which has a 37mm threaded front lens and I was thinking of buying two UV filters or Skylight in order to put the polyester filter in the middle of the two glasses but on a single screw ring. Which of the two glasses do you recommend? .....the uv will not interfere in the spectrum of light that reaches the sensor? What is the best way to laminate Lee polyester film? Could someone kindly explain in detail how I should do it? Many thanks in advance.

EDITOR'S NOTE: UVP supports a one-time new product announcement. UVP is non-monetized and has no monetary association with anyone or any company. I would like to announce the presentation of a new NIR blocking filter - UVROptics NIR-Block. You can see some of the statistics for it at https://uvroptics.com/index.php?NIRBlocking. Although I ran a modest characterization using a Hitachi U-1500, I thank Ulf for offering to undertake a more advanced characterization. Both my split-beam spectrophotometer and Ulf's array spectrophotometer can only go down to OD3, however Ulf has a routine to extrapolate to OD5. I use an Opteka R72 to test NIR blocking on my filters. The images below are from a Lumix GF1 full-spectrum, CZJ 50/3.5, ISO 400, f11. The illumination is sunlight through floor-to-ceiling double-pane windows on a cloudy day. Image1 - NIR-Block, 1/800s. Image2 - R72 over NIR-Block, 10s. Image3 - R72 over NIR-Block, 25s. We are offering the NIR-Block in 52mm diameter and 3mm thickness. I prefer a 3mm over a 2mm in this filter because the slight loss in the UV for the 3mm is more than compensated for by the additional NIR blocking. Below are comparisons of the NIR-Block and the S8612. The attached images show the differences between 2mm and 3mm in both SS8612 and NIR-Block. The Schott programming is taking care of any interpolation between 3 and 2mm. I tested the NIR-Block twice at 3mm on the spectrophotometer. I look forward to your response to this new offering for those who like to stack We also have a new ionic UV-Pass filter on our website. Thank you. Regards, Reed

So it would seem that camera sensors can made a great deal of difference in the raw color outcome of a reflected UV photograph. I'm only having mild panic about this. Given the current state of the world, it seems ridiculous to have any panic at all over photographic trivia. But I am worried that quite a lot of what has been written here over the last 9 years about false colors and raw false colors in reflected UV photography might be, at best, incomplete, and at worst, erroneous or misleading. In the past I've used converted Nikons, a Pentax, a little Lumix and a Sony. They all produced the same false color results whether raw or white balanced. Then along comes the S1R and all my false color facts have been upended. Well, so it goes..... Here is an old photo of Spectralon under SB-140 flash (with its SW-5UV filter) made with a Nikon D600 conversion + UV-Nikkor + BaaderU. Here is a recent Spectralon photo under filtered SB-140 flash made with a Panasonic S1R conversion + UV-Nikkor + BaaderU. It's about 49* different on the color wheel from the preceding. That's quite a lot of difference. So now what? Should I wade through 9 years of topics looking for false color comments to update? Seems rather daunting. Maybe we should just start a new edition of the forum with new Stickies, etc. That seems kind of drastic. Any suggestions welcomed !!! By the way, anybody remember how upset I get when people try to make false color to wavelength correlations and don't realize or take into account how many variables are involved in producing false color? Refer to this topic for one more such variable. I keep hoping I made some sort of stupy mistake. And once I discover it, the second photo will immediately flip into that nice 13* orangey-red.

I purchased a Kolari UV / IR Cut Pro 2 Filter last December & I was impressed with it & the good match for my converted Sigma fp. Unfortunately I opened the box to use it today & I was shocked to see that there seems to be a delamination problem. The outside of the filter seems to be clean, but there are ghosting smear marks that seem to be internal ? Please check your Kolari Pro 2.

I did a 11 mile walk today in Paradise Valley, Arizona - extreme UV index 11 (I'm on business conference for 1 week). Gear Nikon D600 FS (non debayered) - shooting RAWs with Nikkor 50/1.8 AF-D - all handheld: - No filter. - Hoya 720 nm filter. - Hoya UV/IR cut filter - AndreaU - SEU - Hoya U-340. All looked as expected - except the last Hoya U-340 - it has IR leaks which is known to me, so I just assumed I'll shoot for a try - see what happens - I have no S8612 filter with 52mm (and I wanted light setup so I took all my 52mm filters and single Nikkor 50/1.8 AF-D from Poland to USA). Usually that Hoya U-340 was not usable without S8612 - IR leaks - but today ? due to high UV index ? seems like UV and IR recorded just about the same amount of light, so effects were KILLING. When I switched to manual focus I saw that I can focus almost everything twice - once for UV (IR creates blur then) and once for IR (UV creates blur then). This is the photo that was recorded (I need to retry this tomorrow because it wasn't obvious when shhoting - I see this when postprocessing files now): When I shoot photos as JPEG (so camera records anything) I default to monochrome - otherwise everything is all pink - so I include JPG (mono) and JPG from RAW that is just auto-white-balanced via: *dcraw -v -H 1 -a -T -q 3 "$1"* and then processed by my own *jpeg* toool:

PINHOLE test with UV filters The potted sunflowers have arrived. How to try Tangsinuo's filters? Theoretically, only a pinhole has no lens limits. the problems are the necessary power and the reflections of the glass (it would probably be better to put them behind the pinhole) Sony A7 f.s. focal distance approx ~ 45mm ~ f: 300 0.15mm pinhole (non laser, abrasion technology for microscope use) All photos are with 1000w full power studio flash I didn't add saturation, just a brightness and contrast curve. - the first image is with a nude pinhole - QB39 - 50iso - TSN575 + QB5 - 1600iso - TSN575 + QB29 - 1600iso - TSN575 + ZB2 - 1600iso - TSN575 + ZWB3 - 6400iso - TSN575 + ZWB2 - 12800iso - TSN575 + ZWB1 - 12800iso Thanks Antonio

I know this is primarily a UV forum, but having put together my ZBW2 UV filter stack with some cheaper 3rd party alternatives, I've come to realize that I am sorely lacking in overall knowledge regarding light modification techniques and filters. After seeing a post on here showing the Kolari IR Chrome filter I use could be recreated by stacking 3rd party filters together, I tried looking around the forum to see if there were any other interesting combinations or filters. I noticed there isn't a pinned thread or compendium dedicated to comparing various IR and other filters. A dedicated thread/page would be extremely useful for new members such as myself!

I just thought that we may be hasty in cleaning our ionic glass filters that are showing signs of oxidation. As we recall, Lord Rayleigh (John William Strutt, 3rd Baron Rayleigh of Terling Place) discovered the first type of antireflection coating known, in 1886. He found that old, slightly tarnished pieces of glass transmitted more light than new, clean pieces due to this oxidation coating. Of course, we cannot know, without spectrophotometer testing, whether the increased transmission, if any, benefits our particular wavelengths of interest. Still, the possibility that the oxidation is advantageous should give us pause. Another reason for delaying cleaning, is the possible deleterious effects of cleaning. Some have suggested the polishing of the glass with fine ceria (cerium oxide) particles. Ceria is a wonderful substance, and is of especial note as a nanoparticle. I received a patent for the use of such nanoparticles in camouflage in the ultraviolet. In the image below, the the subject is wearing a U.S. Army ACU (FRACU) with the right side of the top and trousers - and the Multicam boonie hat - treated with ceria nanoparticles The top image in visible light and the middle image in NIR light reflect the light as expected. However, the bottom image, in ultraviolet light, shows the wearer's left side as a bright image, while the treated right side blends with the background. (I am simply presenting this as an illustration of the UV absorption of cerium oxide nanoparticles. ) Ceria nanoparticles are inexpensive to produce and readily available down to a size of 10nm. In comparison, human hair is 30,000nm - 90,000nm in diameter. So it is quite easy for ceria to lodge in the invisible pits and crevices of a filter glass. While the ceria would not be visible, it would be absorbing UV. Would it be sufficient to alter the images shot through the filter? I don't know, but caution would suggest avoiding the possibility. Just some thoughts. ymmv.

Went and bought a cheap Hydrogen A narrowband astrophotography filter, and thought I'd test daytime first. Don't have pics, but tested with a diffraction grating, and the 656nm is true, but there's also leaks past 900nm as my 940 torch was pretty bright walking around at night. Might be useful for astro but haven't tested yet. Links to products used https://www.amazon.com/gp/product/B0141U858I/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 https://www.3d-astro.com/ for the 1.25in filter clip in. Canon 77D FS, EL Nikkor 80 metal enlarger for the deeper mounting as the filter sticks out too far for standard lenses Not great time for photography the heat waves were crazy bad this morning. Car was moving on the highway. 1/200th, iso 200, f8 W/B was done on PTFE in camera. Channel swap with red, as it looks better with a blue sky. Used Affinity Photo and darktable for processing raw Here's right out of camera, with contrast and converted to jpeg

Holy thread revival Batman. EDITOR'S NOTE: I moved Jonathan excellent BaaderU experiment to its own topic so that it will be more searchable and also to remind everyone that it is useful to reverse your BaaderU so that the pink side faces the subject. I know we've all been told the Baader U should be reversed for photography, so the pink side faces away from the camera, and I got to thinking how the two sides compared in what they reflect. Slightly odd experiment, but the light source fiber and spectrometer fiber were at 45 degrees to each other. This is a specular reflection setup. However I don't have a specular reflection calibration standard. In place of that I used a 99% diffused reflectance one. This means that my reflectance values in this graph, are in relation to this diffuse reflectance standard. Obviously the Baader U is shiny, and has high specular reflectance, so the values go above 100%. It's fine for comparing one side vs the other, but that's it. I measured both sides - pink and green/gold, on my version of the filter which is about 3 years old. I took the filter out of its holder, so it's the same distance from the fibers to the each side of the filter. The pink side is better at reflecting the IR so it definitely makes sense to have that side facing away from the lens. Not sure whether this has been shown before, so thought I would share it.

I just added a new set to Sphaeralcea coccinea, the Scarlet Globemallow. I was surprised by the interesting difference between the UV and UV+Blue+Green versions. So I wanted to point this out in a separate topic. Why was I surprised? Well, I tend to forget that a UV+Blue+Green filter stack is not necessarily going to replicate a flower's UV-signature [or the UV-signature of non-floral subjects]. I tend to think of such a filter stack as being more UV than UV+Visible. Don't do this!! You'll immediately see why below. [What follows can be applied to any photographic subject, not just flowers.] For reference here is first an unresized crop from a Visible photo of the Scarlet Globemallow. The flower has red-orange petals with white to light greenish areas on the petal bases together with a light greenish base for the cluster of yellow anthers. In UV the flower has a UV-absorbing, dark central bulls-eye except for a small bright patches around the base. The edge of the bulls-eye has a touch of false blue. The petals are a UV-reflective, pale false yellow. This photo was made with a BaaderU UV-Pass filter. Now here is a view of the Globemallow flower made with a 2.0 mm thick U-330 dual bandpass filter stacked with a 2.0 mm thick S8612. The combination passes UV light together with some small amounts of Visible violet and blue light and an even smaller amount of Visible cyan-green and green light. What struck me here was that the preceding UV-dark bulls-eye is not at all evident in this mixed light version. Easy enough to see why. The Visible whitish center of the flower is reflecting all/most Visible colors so it cannot be dark under the U-330 stack. The Visible yellow cluster is reflecting a little bit of green (as Vis yellow often does), so it cannot be dark either. And lastly the pale greenish base of the anther cluster is reflecting green, so it is cannot be dark. I suppose I should finish the reflection analysis. The petals reflect Visible red-orange and also strongly reflect UV. There are often blue components in reddish flowers, so we might be getting some reflected blue from those petals. But most likely the false blue in the U-330 photo is due to the reflected UV which gets recorded by the modded camera in such a way that after white balance, we see this false blue.

Update: 21 Aug 2021 Added links. Update: 26 Aug 2021 Minor edits for clarity. Title improvement. Added Goal and Test statements. CONCLUSION: Post #38 Don't go there immediately. Read thru the experiment and enjoy the s*u*s*p*e*n*s*e, yes? Camera: Nikon D610-full spectrum conversion Lens: UV-Nikkor 105mm f/4.5 Light: Ambient afternoon skylight Filters: In alphabetical order, Baader UV/IR-Cut, BG38, BG39, BG40, S8612. This is not the order in which the filters were tested. GOAL: Which of these 5 filters is best for blocking IR light to give the best Visible color when used with a full-spectrum converted camera? FIRST TEST: During conversion of the photos, apply white balance only to the white or grey patch but do not make any color correction profiles. There follow below 6 Visible light photos. Five (5) were made with IR-blockers and one photo is unfiltered. Conversion was in Nikon Capture NX2 so that a stock Nikon D610 color profile would be used. Capture NX2 can read the picture control settings. Those were Neutral 0. That means there was no extra contrast, brightness or saturation applied when making the photos. And no hue set was given any kind of preferential boosts as can happen with blue and green when using Landscape picture controls. I used three edits only. The Capture NX2 white balance marquee was applied to the white patch (upper right). ADDED: 3 Apr 2024 Subsequent experiments have shown it is best to use one of the grey patches for WB. The black and white points were set using the LCH Tool. That is, I moved the histogram end points as needed. The brightness of the black patch (upper left) was set to 5% using the Black "Luminosity" dropper. The brightness of the white patch (upper right) was set to 95% using the White "Luminosity" dropper. My thought was that uniformity in the darkest and brightest tones would overcome any minor exposure differences and make color analyses easier. Summary: White balance + stock camera profile. Which photo has the best Visible colors? Define "best" however you like. #1 #2 #3 #4 #5 #6

Following my post on using the 405nm laser to image falling snow, I decided that I needed a 405nm bandpass filter that was larger than 12mm (the size of the Omega filter that I used in that series). I bought one online earlier this week, and it arrived today, so I tested it out. The filter I bought was the MidOpt Bi405 25.4mm filter, which has this spectrum, using data given by the manufacturer and replotted by me for easier reading: The filter also has an IR leak which I plugged by stacking with BG38 2mm. Having acquired the filter, I took some photos with it out my window using the Sony A7S full spectrum conversion, and the EL-Nikkor 80mm/5.6 (metal) lens. I then processed the images in PhotoNinja as usual. My settings for PN were with the default values inside the checked boxes. At first everything seemed fine, albeit with a tiny bit of blurriness that I didn't usually get with the EL-Nikkor: But a closer examination showed something was very badly awry! Here is a crop of the above image enlarged 300% with nearest neighbor interpolation: It looked horrible. Mind you, it looked like this in the original TIFF and in the RAW converter, so that blockiness isn't JPEG artifacts. I did wonder at first if it might be caused by the fact that Sony uses compressed RAWs in their A7S (uncompressed is not an option) but further investigation convinced me otherwise. Because the next thing I tried was processing the image with Adobe Camera RAW, with very different results. ACR, with "Adobe Monochrome" and 16 bits selected, produced the following rendition, again with all default settings unmodified: Full size: Crop at 300% with nearest neighbor interpolation: MUCH better. So the conclusion I'm drawing is that when all the information is in one channel (blue here), PhotoNinja has serious issues processing the RAW, but Adobe does not. LATE BREAKING UPDATE: While there is about 2 stops more blue in the RAW than red and green and green2, RAW Digger (yes I own it finally) says there's plenty of the latter.

[Filter Test SEU Gen2 #1] Introduction to the SEU Gen2 [Filter Test SEU Gen2 #2] White Balance, Raw Histogram & Andrea's "White Signature" [Filter Test SEU Gen2 #3] Filter Speed & A Windy Bull's-eye [Filter Test SEU Gen2 #4] Dealing with the Usual Dichroic Effects [Filter Test SEU Gen2 #5] Landscape Interlude [Filter Test SEU Gen2 #6] Monochrome Museum Comparison [Filter Test SEU Gen2 #7] Measured Filter Transmission [Filter Test SEU Gen2 #8] Dichroic Reflection Detour [Filter Test SEU Gen2 #9A] Longpass Stack Wandering Discussion. See #9B for results. [Filter Test SEU Gen2 #9B] Longpass Stack Results [Filter Test SEU Gen2 #10] What good is a filter test without a Rudbeckia? [Filter Test SEU Gen2 #11] A Fascinating New Rudbeckian View [Filter Test SEU Gen2 #12] Summary Monochrome Museum Comparison I recently visited Speyer in Germany, and went to the Technik Museum there. I had with me my monochrome converted EOS 5DSR and 85mm Asahi Ultra Achromatic lens, as well as Baader U, StraightEdgeU Gen 2, and Heliopan 715 filters. MONOCHROME MUSEUM TEST: Photograph a museum exhibit in sunlight using the Canon EOS 5DSR UV-Monochrome Camera with different filters, and compare the results. Question: How does a museum exhibit look with a monochrome camera with the new SEU Gen2? Answer: Differences were observed between the Baader U and StraightEdgeU Gen 2 filter rendering, in terms of exposure and reflection from the surfaces imaged. StraightEdgeU Gen 2 filter shows some UV and some visible characteristics. On the monochrome camera conversion the StraightEdgeU Gen 2 filters appears to let slightly more light through than the Baader U, but this consists of visible as well as UV. Subject: Aircraft, building and sky. Location: Speyer, Germany (Lat 49.32N, Long 8.44E) Gear: Canon EOS 5DSR monochrome conversion + 85mm Asahi UAT + Baader U, StraightEdgeU Gen 2 and Heliopan 715 filters + Sun UV-Pass Filters:Baader U, StraightEdgeU Gen 2 and Heliopan 715 filters Exposure: f8 @ ISO-400 Conversion: Taken as JPEGs directly in the camera, using custom white balance based on PTFE tile. Comment_1: All shots done with direct sunlight, although some cloud cover was present in the sky. Comment_2: Did not do a control shot with UV/IR blocking filter. Control shot was done with no filter, so contains information from UV, visible and IR. Comment_3: Shots were hand held, hence the slight change in alignment between each one. Unfiltered - UV, visible and IR 1/1600th s exposure time Baader U 1/25th s exposure time StraightEdgeU Gen 2 1/25th s exposure time StraightEdgeU Gen 2 1/40th s exposure time Heliopan 715 1/250th s exposure time There were some strong differences in the rendering of parts of the image with the Baader U and StraigthEdgeU Gen 2 filter. Notably the lettering on the main plane, along with the chequer patterning on the engine intake, and the arrow on the fuselage, where they became almost indistinguishable from the main paint odf the plane with the Baader U. Not all lettering behaved the same way though - at the bottom of the image one another plane was the word 'Texans'. Although not visible in the full spectrum image, it appeared dark against the plane body in both UV and IR images. The painted lettering on the museum wall was interesting - the letters were lighter in colour than the surrounding painted section in the UV and IR images, comapred to the full spectrum one. This suggest the paint used for them is dark in the visible spectrum but more relfective in the UV and IR, perhaps due to the pigments used. The StraightEdgeU Gen 2 filter lets some short wavelength visible light through in addition to UV.

Purchased super inexpensively. Thought I was buying an 850 IR filter, similar to the small 40.5 for the Pentax 645 DFA 25 mm lens. Nope, instead of dark black, this filter is super dark metalic purple. So what is this used for on a full spectrum camera? Thanks, Doug A

Apparently Kolari Vision has a new version of their IR Chrome filter. I take this as an opportunity to point out again that the filter has little to do with Aerochrome (although they still market it that way) and can be created cheaply and simply by yourself. https://kolarivision...ilter-preorder/ This has already been discussed in this forum. I did a comparison on my blog - The combo of Peacock Blue from Lee and a Chinese Hot Mirror gives exactly the same look. Here is the post for all interested: https://hiddenrealms...-chrome-filter/

New Baader U filter. No side is pink for the “flip”. The side with female threading is gold/yellow depending on angle to light. The male-threaded side is green/blue, depending… So mounting it “normally” on a camera lens would put the gold/yellow side facing the subject. I do have a male-male adapter so I can “flip” it without any trouble. Pix below were shot with my iphone under an ordinary desk lamp. So flip or no flip?