[LargeFormat] Observation...

[Richard Knoppow]

----- Original Message -----
From: "tripspud" <tripspud@transbay.net>
To: <largeformat@f32.net>
Sent: Tuesday, February 04, 2003 1:27 AM
Subject: Re: [LargeFormat] Observation...


> Hi Richard,
>
>      Plus I think the Commercial Ektars were basicly
> larger sizes that was common for the era.
>
> Rich
>
> >   The curious thing is that the 203mm, f/7.7 KA and
Ektar
> > were offered by Kodak as economy lenses for 4x5 and 5x7
view
> > cameras where the cost of a Commercial Ektar was not
> > justified.
>
>
  I don't know about that. The Commercial Ektars started out
as Eastman Ektars with soft coating on interior surfaces and
became Commercial Ektars with the advent of economical
vacuum hard coating around 1946.
  These lenses were made in focal lengths from 8-1/2 inches
to 14 inches at f/4.5.  Tessar  and Dialyte lenses of
similar focal length and speed were also made by Kodak as
Kodak Anastigmats beginning probably in the early 1930s.
Before that Kodak bought most of its lenses from Bausch &
Lomb.
  B&L, Zeiss, Wollensak, Schneider, Voigtlander, etc., all
made large format lenses in focal lengths up to perhaps 20
inches and process and special purpose lenses of much longer
focal lengths.
  There was a fairly wide choice of Tessar type lenses of
f/4.5 aperature up to at least 12 inches. Goerz also made
f/4x5 Dogmars to 12 inches, longer ones being f/5.5.  B&L
listed f/4.5 Tessars to 19-1/2 inches and Zeiss to 20
inches. These must be impressive chunks of glass. The great
speed was mostly to get limited depth of field for portrait
work.
  Both B&L and Zeiss offered Tessars as f/6.3 lenses. These
were cheaper but probably better than the faster lenses.
  One problem with making fast LF lenses was simply finding
large enough chunks of glass to make the blanks from. Modern
technique makes blanks by molding so size limited by other
factors such as the mechanical properties of the glass.
  Keep in mind that large format was pretty much the
standard for professional photogaphy back when men were men
and women wore bustles so lenses of appropriate focal length
were available.
  BTW, correcting the prices from my c.1905 Bausch and Lomb
catalogue as well as possible to modern prices shows that
large lenses were alway very expensive.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com