Archived posting to the Leica Users Group, 2000/11/08

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Subject: Re: [Leica] Focus Mark for Infrared Film.
From: Guy Bennett <guybnt@idt.net>
Date: Wed, 8 Nov 2000 08:59:49 -0800

>I know that the focus point for the use of IR film has to be changed - I
>don't see any such marks of any of my Leica lenses (35, 50, 90 Summicrons).
>
>Is there a reason for this, what is a rule of thumb that could be used ?
>
>Regards,
>
>Peter Zak.


one rule of thumb for 50mm lenses is to move the focus point to aline with
the 5.6 dof indicator to the *left* of center.

another trick, better with the 35 than with the other focal lengths you
mention, would be too rate the film at 200, set shutter speed at 125 then
stop down to 11 and let the dof take over.

guy

Replies: Reply from "Tom Schofield" <tdschofield@email.msn.com> (Re: [Leica] Focus Mark for Infrared Film.)
Reply from "Tom Schofield" <tdschofield@email.msn.com> (Re: [Leica] Focus Mark for Infrared Film.)