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  2. Lou Jost
    In these kinds of discussions we always have to remember that some traits are just accidental byproducts of some other traits that are under strong selection. Scotch tape is luminescent when pulled from its roll, and mints glow when they are broken, but this is just an accident of chemistry and physics, not something that helps Scotch tape stick better or makes mints taste better. While some (probably most) bioluminescence has important biological functions, that is not necessarily true.
  3. Today
  4. BenjaminK
    That second picture is beautiful, the bees look gilded.
  5. JMC
    Thanks guys. Cheers for verifying that David. The images are uploaded at full resolution (some are up to a 100Mp) so it is good to know that pinching to zoom works on a phone.
  6. colinbm
    Excellent web page Jonathan.
  7. Stefano
    False color saturation is a good way to judge UV reach.
  8. Stefano
    Seems like all 50/1.8 lenses or the like are reasonably good. Did it lose sharpness because of monochromatic aberrations (like spherical) or chromatic aberration?
  9. Stefano
    This one has richer lavenders, apparently it's the paint and not the camera.
  10. photoni
    BIG Jonathan
  11. photoni
    Colin ... 1968 flower power :)
  12. photoni
    I forgot... to do the "above" test with 365 nm light I didn't use a lens but a pinhole. The easiest and most practical test to test a lens, I think, is to photograph a common daisy that turns a beautiful blue-purple, with a yellow dandelion or bidens next to it that turns yellow with a black center... if the lens it's good ... otherwise everything is dull or gray.
  13. colinbm
    Thanks Doug & Benjamin, There will be more soon.
  14. Andy Perrin
    I think that’s been known for a long time now but I still think it’s funny that manufacturers misleadingly call them UV filters!
  15. lonesome_dave
    You are right! I recently checked a number of UV filter glasses I had removed so I could use the filter mount for something else and discovered they are basically transparent to the near-UV spectrum.
  16. Yesterday
  17. Andy Perrin

    Should we test modern lenses for UV?

    Andy Perrin replied to Stefano's topic in Techniques, Tests & Gear

    I seem to recall that my Sony Zeiss 55mm/1.8 FE lens passes a decent amount of UV-A, although I wasn't particularly happy with the sharpness of that lens in UV (it is VERY sharp in visible light, but we have discussed in the past why that might lead to bad results outside of visible).
  18. nfoto
    This particular scene never comes out with strong false colours, even when saturation is pushed way beyond the reasonable.
  19. dabateman
    He is using a standard (stock) camera, so the sensitivity to UV and IR will be low. I can't remember if the Hoya filter blocks any UV, most UV filters don't block any UV. They are used to "protect" a lens, or just degrade the image quality so you can have lens wars on online gear forums. To be safe I use 2A or 2E wratten filter. The 2E is best, but hard to find now. My favorite blocker is the internet dust protection filter from a Sigma SD15 camera. I likethe first image better than the second. Has a defined subject.
  20. Foxfire
    It is a great idea to use a portable dark-box, i think i have to build one. If using UV cut filters, i'm suggesting to look into Baader UV/IR-Cut, as there might be also some IR fluorescence while doing UViVisF.
  21. Foxfire
    @BenjaminK Yes, this is one prominent theory. I've looked into it and have to say i'm not really convinced. Fungal spore dispersion happens anyway quite effectively with air currents. But who knows, it might be true for some species, although i'm in a doubt about it :)
  22. BenjaminK
    These are images from my first UVIVF shoot using a TATTU UV torch (ZWB2 filter), a standard Canon 6DII, and a Sigma 105mm lens with a Hoya UV filter. The shoot was done inside a portable soft box which I tried my best to eliminate all external light sources from (I don't know how successful that was, though!). I like the results, but I'm not sure what it says about my set up. Settings for first photo: f/8, 13 seconds, ISO 100 Settings for second photo: f/22, 30 seconds, ISO 1600 Any suggestions about what these images show from a technical perspective?
  23. BenjaminK

    UVC IVF of a Sunflower

    BenjaminK replied to colinbm's topic in Ultraviolet & Multispectral Photos

    Striking image. The petals look unreal.
  24. BenjaminK
    I like this explanation! I suppose for glowing fruiting bodies it's to attract insects in order to disperse spores?
  25. Doug A
    Beautiful colors. We don't see many UVC induced fluorescence images. Thanks for sharing, Doug A
  26. VideoJohn
    Me and Bambi need to go out again sometime.
  27. dabateman
    Thanks Jonathan. It actually looks fine on a phone. You can easily pinch to zoom in or click on images.
  28. JMC
    If it's of interest, I've now created a website for my high res microscope images of diatoms - https://diatomimaging.com/ It's a sort of online museum, showing the images of the diatoms, along with details on how they were taken, and also the slide they are on. There are a few UV images on there, but mostly they are done with 450nm LED light. It is best viewed on a desktop or laptop as I have disabled the zoom function for mobile devices (feedback from users said it didn't work very well).
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