[rollei_list] Re: Tell the tales of Triotars
- From: Eric Goldstein <egoldste@xxxxxxxxx>
- To: "rollei_list@xxxxxxxxxxxxx" <rollei_list@xxxxxxxxxxxxx>
- Date: Mon, 6 May 2013 17:24:06 -0400
On Mon, May 6, 2013 at 5:15 PM, Sanders McNew <sanders@xxxxxxxxx> wrote:
So, would you then say that, controlling for sample variation, an f/3.5
> Planar should outperform an
> f/2.8 Planar at any given aperture?
>
They are different FLs and also different designs, so this is kind of
apples to oranges...
And -- separately -- is there any merit to the practice of stopping down
> one stop from full aperture to
> improve resolution (or flare)?
>
Since there are virtually no lenses for photographic purposes created at
optimal speed, yes. If you were shooting one of the rare lenses well
designed at optimal speed, no.
I think Cosina created a 50mm/3.5 Heliar for 35 MM which was purportedly
designed at optimal speed and supposedly at it's best wide open. There are
Leica lenses which are at optimal performance stopped down 1 f/stop. My
50/2 screw-mount collapsable Summicron from 1950 is best at f/4.5 or so...
MF lenses are a different story, however...
Eric Goldstein
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