Re: 4x5 focusing

[boblong@xxxxxxxxxxx (Robert Long)]

On Sun, 21 Jul 1996 19:52:42 +0200, John Gateley wrote:

|I'm familiar with the IR focus marks on 35mm and Med Format cameras, but I
|recently started shooting 4x5 Kodak IR film.  How does one handle the shift
|in focus, or does the fact that all of my shots so far have been at =9F16 or

My approach when I used 4x5 was to use a tripod and a slow shutter
speed and stop the lends down--probably to f/16 just as you did.  But
I also used to rack the front standard out a smidge (no more than 5%)
in the hope that that would help.

In a post elesewhere a month or two ago I read the statement that
stopping down too far causes diffraction that increases the tendency
of IR to create "halos."  I remain skeptical.  I'd like to hear
opinions from our motly but fascinating crew.

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Topic No. 32