Bob Atkins on lens testing

For historical reasons, and some food for thought:
"Lens Testing for Resolution, Chromatic Aberration and Distortion"
bobatkins.com/photography/technical/lens_sharpness.html

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

David

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

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.

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.

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 😌

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

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.

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

Unpredictable, try sensor cover glass instead, like Schott D 263 T eco or D 263 LA eco - that works.
www.schott.com/en-be/products/d-263-p1000318/product-variants?tab=d-263-la-eco

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.

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.

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

Correct.