[rollei_list] Re: Question re. Planar vs. Tessar
- From: "John A. Lind" <jalind@xxxxxxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Sun, 03 Apr 2005 10:48:39 -0500
At 01:02 AM 4/3/2005, Ardeshir wrote:
>So I gather that the Tessar is supposed to be an IMPROVEMENT over the
>Planar. Why, then, is the Planar generally preferred over the Tessar
>among users of the 6x6 format, whether SLR or TLR? Any ideas? Richard
>... ?
Not the current formulation(s), but the original from the late 19th
Century. Keep in mind that a lens name is just that, subject to
reformulation and "derivations" over time. The Sonnar, of which I have two
different formulations . . . one on a circa mid-1950's Contax and another
on a circa 1978 Rollei 35S . . . are similar in concept but substantively
different in design execution . . . the former an f/1.5 having 7 elements
and the latter an f/2.8 having 5 elements (presumably a reduction in design
complexity as lens speed was reduced).
AIFK, from the research I did before writing about the Tessar, the current
Planar is substantially different from the original created in the late
1800's. I came to the conclusion the current one is a very loose
derivative of the original concept. The f/3.5 Tessar on the Rollei 35[T]
has very high contrast and produces great sharpness, but does not have the
flatness of field found in the f/2.8 Sonnar on the Rollei 35S (which also
seems to be a tad lower in contrast). If given a choice of 4 element
Tessar, 5 element Sonnar or current Planar in standard focal length on a
35mm camera body, I'd likely choose the Planar.
-- John
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