Re: Adjusting older cameras to focus IR

["J.Wood" <shopper@xxxxxxxxxxxxxx>]

At 04:35 PM 4/21/97 +0100, you wrote:
>Hi folks.  I'm brand new to the list, and just about brand new to IR.  I
>have some old Yashica TLR's, and a Crown Graphic 4x5 with some ancient
>lenses.  What ratio, and in what direction, should I adjust these
>cameras to focus IR?
>
>thank you.
>
>-- 
>

Kodak recommends "an extension of the bellows by 1/4 of 1% of the focal
length of the lens."  My experience with large format IR is using a tripod
and f16 and smaller and making no adjustments.  If you are using a Yashica
TLR you will be using Konica 750 and almost certainly on a tripod also.  

If you use 4x5 IR your major concern will be loading and developing.  Use
lint free gloves to load and unload your film holders unless your hands are
oil free and ph neutral.  Also use metal sheet film holders if possible, and
do not remove the dark screen completely from the film holder when exposing.
Film holders leak IR through the felt lining around the insert.  If your
equipment is like mine, wrap your film holders in aluminum foil for
transport and lay the foil on top of your bellows if you leave the dark
slide out for a while.  

Jim Wood


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