• IliahBorgpanorama_fish_eye
    976 posts
    2 years ago
  • 2 years ago

    Thanks, Iliah! A good article, and the site has many more such.

    David

  • JimKassonpanorama_fish_eye
    1738 posts
    2 years ago

    I think lens screening testing should be quite different from lens performance testing. For screening you can use much simpler and faster methods.

  • DonaldBpanorama_fish_eye
    2378 posts
    2 years ago

    not a very good way of testing my lens 😜 i just received a used microscope objective yesterday and how i test my lens
    is find the smallest fly or spider with the finest of hair folicals you can and see what lens produces the sharpest image with the least purple fringing, its a simple as that no maths no charts just pure common sense. and im very happy with the results, great buy.

  • IliahBorgpanorama_fish_eye
    976 posts
    2 years ago

    As any surface irregularities are magnified, and become very vivid in coherent light especially, shining a laser pointer on the front lens of the microscope objective along its axis while having the objective connected to a small camera is a good way of checking for imperfections.

  • DonaldBpanorama_fish_eye
    2378 posts
    2 years ago

    my major problem is i have to shoot through a piece of slide glass which houses the bugs and get a bit of haze from the led lights. what is the highest quality glass for slides ? also you have just given me an idea 😀 i cut my glass slides into 10x10mm square and mount them on a 20 mm plastic cylinder and shoot through the optical slide glass. but because my led lights are shinning on the edge of the glass i might have to paint them black ! do you think that would make a difference to glass flare/haze ? im working for the next week so cant experiment for a while 😌

  • DanHasLeftForumhelp_outline
    4254 posts
    2 years ago

    Or take the easy way out and use AI. Who's going to know the difference!!! 😮😮😎

    I created this macro using AI.

    https://www.bing.com/images/create


    dprevived.com/media/attachments/75/8a/DkR8OVCAbjFrkPKZjqcroz2FMXBRGyYjfNQCkqiEoP7pwcfOd9iRioQzg1NEG8J5/antmacro-2.jpg


    dprevived.com/media/attachments/23/08/IS7Ha54qbRdPILkgTh2rEIVUjREqpnQLAZTp7ZGaP4wCLgyeBpBoq67PS4gWLeWq/bingimagecreator.jpg

  • IliahBorgpanorama_fish_eye
    976 posts
    2 years ago

    Expensive.

    Yes, it makes a difference. I use masking tape, or "BLACK 2.0" paint (3.0 version has lower adhesion to glass), matting out any secondary light sources I can.

  • DonaldBpanorama_fish_eye
    2378 posts
    2 years ago

    do you think if i cut up a hoya uv filter it would have less flare/haze than a slide glass ?

  • IliahBorgpanorama_fish_eye
    976 posts
    2 years ago
  • DonaldBpanorama_fish_eye
    2378 posts
    2 years ago

    did a quick test today before i head away for 5 days. shot the surface of a leaf with the invisable to human eye the fury surface.
    no cover glass, cover glass ( new) and hoya good quality uv filter./ lens protector.
    the hoya was way worst, but to my surprise the new piece of cover glass was near identical if not slightly better than nothing in front of subject.
    i have no idea what happened there as cover glass has always had a bit of haze. may be my old pieces needed replacing.

  • IliahBorgpanorama_fish_eye
    976 posts
    2 years ago

    A lot of counterfeit "Hoya" glass floating around, and in a lot of cases those who cut filters from bulk glass, pack them, etc. mistreat it. I mentioned how I check quality of the system.

  • DonaldBpanorama_fish_eye
    2378 posts
    2 years ago

    ive been reading that some slide glass has coatings on 1 side and when using them for microphotography they turn them over.

  • IliahBorgpanorama_fish_eye
    976 posts
    2 years ago

    Correct.