Just some suggestion, for film use Velvia, for viewing use microscope
or a 20x lupe. If you have other macro of similar focal length lenses,
use them for comparison.
C.H.Ling
Jim Brokaw wrote:
>
> I was thinking about this recently, and - without getting too involved -
> what is a good way to test a lens? I'd welcome comments on my proposed
> procedure:
>
> I thought maybe I'd tack an opened flat newspaper page up on the wall (in
> sunlight) and set up the camera on a tripod. Vary the distance i.e. close
> (minimum focus) medium (6-8 feet?) and distant (15-20 ft?) and maybe a
> couple shots further out. Or should I use some multiple of the lens' focal
> length? Then shoot (slide film) a range of exposures varying aperture and
> shutter speed, being careful to minimize camera vibration on each shot.
>
> Project the slides big, focus the projector carefully, and then go up and
> look close at the projected image. Being black and white (approximately) it
> should show some contrast information as well as sharpness.
>
> I know there are test charts you can buy, but I'm not getting that obsessive
> or scientific about it. I'm just curious enough to invest a roll of film and
> developing to see what I can see.
>
> I recently got a Vivitar 90/2.5 macro lens, and I want to see if the lens'
> reputation is justified...
> --
>
> Jim Brokaw
> OM-1's, -2's, -4's, (no -3's yet) and no OM-oney...
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