T3D Re: TECH-3D digest 473

[John Slivon <frogs@xxxxxxxxxx>]

Michael Kaplan wrote:

>I shot a roll of slides using the 2.8 Ektars in the 23mm x 24mm format.
>While significantly better than the David White 3.5 Anastigmats, there was
>still slight but noticeable vignetting (at f11 - f16). I suspect all of
>these lenses, however, were optimized for f5.6 - f8 which was the range
>most used with Kodachrome.
>
>It would be nice to find a modern replacement for the factory Realist
>lenses. 
>
Michael,

I'm surprised that you were getting vignetting in the corners of a 
23 x24 frame with the ektars. On the 7-p realist conversions that I have
done, the ektars have been the best performers, showing sharpness into the
corners at f/4 -22 after the conversion. My experience has shown that the DW
2.8 lenses do not vignette in the same manner as the 3.5's and that in true
tessar form, the coverage increases as the f/ number gets larger, providing
excellent sharpness into the corners at the smaller apertures. The
negatives, made on tech pan, and developed for a long continuous tone, show
good sharpness across a 29.5mm wide frame at apertures of 5.6-22.

Finding replacement lenses for the realist and installing them in the camera
are two different dreams. The rikenon point and shoot lenses in my original
conversion are very good but were a nightmare to install.

I'd like to see your test equipment. 

John Slivon


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End of TECH-3D Digest 475
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