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Re: Picking a Mark IV Lens
On Thu, 15 Jan 1998 14:39:54 -0600, Tom Droege <droege@FNAL.GOV> wrote:
*>This note will be concerned with the process for making a lens choice
*>for the Mark IV.
*>Let us compare the proposed 400mm f/4 with the 350mm f/4 Mak that I
*>have just purchased. The pieces needed to make use of this lens come
*>to about $300. This includes the focal reducer that changes it from a
*>500mm f/5.6 to a 350mm f/4.
*>The proposed lens is good over the whole chip. At least that is the
*>design. We suspect that the Mak will not be so good in the corners.
*>I arbitrarily propose that it will have a 70% good area. This is not
*>so far from my (limited) experience with the 135mm f/2 I have used for
*>tests of the Mark IV.
Tom, can you not measure the image projected by the Mak rather than
estimate it? (Say by daylight projection of an image onto a white surface:
it would be rough but informative. And of course the manufacture may be
able to tell you right off.) Finer measures would require some effort
to build a camera that would expose film across the entire width of
the image field (I believe a standard 35 mm camera would not be wide
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