What subject to photograph for lens testing?

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Planapo
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Location: Germany, in the United States of Europe

What subject to photograph for lens testing?

Post by Planapo »

As said before, I´m going to test some cine lenses for macro, reversed on bellows .
What would you recommend as a handy test subject to photograph to find out how the lenses perform and to compare one and the same lens at different aperture settings?
And btw, where should I turn the focus ring on these lenses? I would assume to maximum near.

Thanks,
Betty

rjlittlefield
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Post by rjlittlefield »

Moth wing. Mount it flat and in focus plane as much as possible. Shoot a short stack with electronic flash so you don't have to worry about vibration. Use lots of diffusion to avoid specular reflections that are mismatched between tests. Be sure to save the wing -- you'll want it later for more tests.

Maximum near focus is always safe. But with most lenses it really doesn't matter because they have no floating elements. The whole lens moves as a unit to focus, so there is no optical difference between turning the ring and changing the bellows extension.

--Rik

Planapo
Posts: 1533
Joined: Tue Nov 07, 2006 2:33 am
Location: Germany, in the United States of Europe

Post by Planapo »

Thanks Rik, for your good suggestion.

I was trying to get hold of a moth during the last two nights with a big white sheet backlit on our backyard balcony but, darn ... none showed up. Maybe it´s still too cold after sunset. But sooner or later I will find one.

Betty

Charles Krebs
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Post by Charles Krebs »

I agree with Rik, but I have one caveat. I have come across certain moth wings (usually small scales, dull brown color) that I just can't seem to photograph to show good detail. (I really should put one on the compound scope at very high mag just to see if I can see some unusual surface texture or other characteristic that might cause this). I generally use a mounted butterfly wing that has served well for this purpose, but many (most?) moth wings work just as well.

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