Re: ULF lens wanted

From: Richard Knoppow ^lt;[email protected]>
Date: 02/14/05-09:00:20 PM Z
Message-id: <001701c5130a$7f66a040$9cfc5142@VALUED20606295>

----- Original Message -----
From: "Schuyler Grace" <>
To: <>
Sent: Monday, February 14, 2005 4:20 PM
Subject: RE: ULF lens wanted

>I happen to have a Goerz 30" APO Artar (f12.5) in an Ilex
>No.5 shutter that
> I don't use very much any more. If anyone is interested,
> I might part with
> it for the right price. I know it will cover at least
> 8x20, and it should
> cover 20x24 with no problem.
> -Schuyler
   It will just make it at infinity focus. Lenses like the
Apo Artar have a rated coverage of around 45 degrees but
will actually cover around 55 degrees if one doesn't mind
slightly soft corners. Even though these were made for unity
magnification they hold their corrections unusually well
with change in object distance and are very sharp at
infinity. Since the lens must be stopped down for reaonable
depth of field anyway being slow is no problem. The generic
type, known as a Dialyte, has the property of not increasing
coverage much when stopped down and having very rapid
degradation of image quality beyond its limits.
   General photography lenses, other than telephotos, were
seldom made in focal lengths over about 20 inches.

Richard Knoppow
Los Angeles, CA, USA
Received on Mon Feb 14 21:00:41 2005

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