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Like it, or not, flowers are one of the most fascinating and varied subjects that we can photograph in UV. The following papers were of interest to me recently because of their photographs of floral UV-signatures. I did not read these papers with any intent to prove or disprove their methods or conclusions. I was simply interested in what gear they used and how they made multispectral stacks. Also, I was interested in the particular flowers they photographed or analyzed. A bee’s eye view of remarkable floral colour patterns in the south-west Australian biodiversity hotspot revealed by false colour photography Klaus Lunau, Daniela Scaccabarozzi, Larissa Willing, Kingsley Dixon Annals of Botany, Volume 128, Issue 7, 9 November 2021, Pages 821–824, https://doi.org/10.1093/aob/mcab088 Published: 03 July 2021 LINKIE Do go look at the photos. Also, lots of interesting info about UV-signatures, pollination, etc. I've really enjoyed this paper. Here is the gear these folks used: full-spectrum Panasonic GH-1 Ultra-Achromatic-Takumar 85/4.5 Baader UV/IR-Cut, BaaderU white Teflon disc (Hey, you saw it here first...... . Birna was using that GH-1 ten or more years ago with a UV-Nikkor.) They made a UV and a Vis photo of the flower. The files were split into R, G, B channels. The stack was made using ImageJ like this: UV blue channel --> blue Vis blue channel --> green Vis green channel --> red (Hey, you saw it here first...... But none of us got a published paper from our multispectral stacking efforts. Oh well. ) This paper only has a couple of photos, but is still interesting. Flower Colours through the Lens: Quantitative Measurement with Visible and Ultraviolet Digital Photography Jair E. Garcia, Andrew D. Greentree, Mani Shrestha, Alan Dorin, Adrian G. Dyer Published: May 14, 2014 https://doi.org/10.1371/journal.pone.0096646 These folks used a Canon D40 + Canon 100mm EF for Vis, Fuji S3 UVIR + UV-Nikkor 105/4.5 + BaaderU for UV, Nikon Speedlight SB-14 (modified by our member Shane Elen), a white reflectance standard, Color Checker Passport, grey barium sulphate target. This is a complex paper with some serious spectrometric analysis. The authors wanted to use the linear response from the cameras so math ensues. But I was wondering if the linear data couldn't be extracted with Raw Digger? Or just Dcraw from the command line. Some EXCELLENT points are made about camera response and human vision. (Example: "Camera responses are not radiometrically faithful for" "highly saturated, human-perceived yellow and orange colours" of Gazania rigens and Sonchus oleraceus. I note that this seems to also be valid for human-perceived violet and violet-blue colours.) cool website: http://www.jolyon.co.uk Garden Flowers in Bee Vision http://www.jolyon.co.uk/2020/07/garden-flowers-in-bee-vision/ Beautiful photos. ((Although you already know my comment about using reds and magentas for bee vision. )) AND FREE, OPEN-SOURCE SOFTWARE !! Must look into this. http://www.jolyon.co.uk/2019/04/a-new-home-for-the-micatoolbox-empiricalimaging-com/ Excerpts from table of contents: How to Make Your Own Camera Calibration How to Make Your Own Colour & Grey Standard Creating a Calibrated Mspec Image False-colour photography: a novel digital approach to visualize the bee view of flowers Christian VerhoevenHeinrich-Heine-University Duesseldorf Zong-Xin RenChinese Academy of Sciences, Kunming Klaus LunauHeinrich-Heine-University Duesseldorf DOI: https://doi.org/10.26786/1920-7603(2018)11 2018 LINKIE https://pollinationecology.org/index.php/jpe/article/view/482 Do look at the photos. They are quite nice whether or not you agree/disagree with the methodology. Full-spectrum Panasonic GH-1 + Ultra-Achromatic-Takumar 85/4.5, white Teflon, grey spectralon, Baader UV/IR-Cut, Nikon D40 camera with low-pass filter, 18-55 mm Nikkor lens and a 105 mm UV-Nikkor lens. (Details not fully supplied on all gear or how it was used. Was that 18-55 used for UV?? Later there is made mention of an inexpensive "plastic lens" used for UV photos, so maybe it was that old 18-55?) The UV-pass filter, the blue-pass filter and the green-pass filter are not specified. Why? Three photos were made: UV, visible under blue filter, visible under green filter. The files were channel split. Then a multispectral stack was constructed: Green Filter Green Channel --> Red Blue Filter Blue Channel --> Green UV Red Channel --> Blue [[Or perhaps we should tell them just to use a Bug filter ??? Sorry, I just couldn't resist. ]]

I hope this has not been posted already: Recording animal-view videos of the natural world using a novel camera system and software package | PLOS Biology

There has been a lot of research over the last few years about whether spiders webs actually attract their prey to the web rather than the prey blundering into it. I have started to photograph various webs and their spiders to see if I can illustrate this. This is an example from this morning. Not sure if this is showing anything useful. They are difficult to shoot logistically - finding a web in the right place for example. The species I would live to try are tropical Nephila spiders (Golden Orb spiders). Species: Araneus sp. with captured wasp (still just alive) Camera: Nikon D800 full spectrum conversion. UVR: Baader U filter with Nikon 105mm UV Nikkor. 4 x full spectrum converted Metz 45CT flash guns. 1/160th second @ f/11, 400 ISO. "White balanced" in PhotoNinja. Visible light: Kolari Hot Mirror filter. Normal flash @ f/11

I have been taking a lot of photos lately. This time I decided to investigate a pair of cucumbers. I illuminated them with a halogen spotlight, which emits enough light for IR, visible and UV. IR tri color is using my GRB3 method UV is taken with a ZWB2+QB39 stack (which surprisingly does not leak significantly, even with halogen) I will also be including the individual pictures if anyone else wanted to take a shot at processing them (please, do post). I'd especially appreciate if someone managed to stack all 7 channels continually. I only could stack them by binning the visible and the IR part of the spectrum together. The pictures are in full hd so if you still have a 1080p display, you might want to enlarge. visible IR tri color 850nm+720nm+red Aerochrome simulation GBUV full spectrum individual color channels: 950nm longpass ~850nm band ~720nm band red band green band blue band UV band (400-350nm) I also decided to stack the images in Photoshop and pick the range stack mode, I got interesting results. All of the bands stacked: All of the bands except for UV stacked: IR only stacked: IR only stacked (normalized): Bonus: IR stacked, normalized and processed with Topaz Denoise AI: Here's the IR range mapped on the visible image: Here's the range between 720 and 850 bands mapped on the visible image:

Here's a recent article describing the colorful iridescence of hummingbirds that explores how it works and what it is for. Visible + UV iridescence is described. Lots of great hummer pics of course. https://www.allaboutbirds.org/news/what-is-the-essence-of-iridescence-ask-a-hummingbird Edit: I see there is a Fauna forum. Please move this post there.

Winginit (2021) Argiope aurantia Lucas, 1833[1] (Araneidae) Black & Yellow Garden Spider. Arachnid photographed in visible light and in mixed light (as emulation of bee vision). LINK Location: North America Comment: I enjoy seeing these in the garden and try not to disturb their papery egg sacs when I discover them. Here's one taken last fall with the simulated bee vision setup that had just come together. Reference: 1. Wikipedia (acc 29 Oct 2023) Argiope aurantia. Wikimedia Foundation, San Francisco, CA. LINK Equipment: Olympus E-M1(full spectrum) + Sigma 30 mm f2.8 lens "Bee Vision" filter stack: U-330 (1.5 mm) + S8612 (2.0 mm) Image combined using ImageMagick. Natural light (l) added for comparison.