Re: Problem with Wisner 4x5 camera probably solved!

[John Sparks <sparks@xxxxxxxxxx>]

George L Smyth <GLSmyth@xxxxxxx> wrote:
>campbell@xxxxxxxxxxxxxxxxxxx wrote:
>>
>>      A question for you, does anybody know if a plastic dark slide is
>>      opaque to infrared? I am using Fidelity Elite film holders.
>
>I don't "think" that the slides are IR opaque.  Many slides have a
>series of five bumps on the part you grab.  This indicates that the
>slide ir IR opaque.  My Fidelity Elite slides have a series of more than
>five bumps.  I don't know what this means, but a friend of mine told me
>that he had problems with his.  I use the Riteway holders for my IR
>without problems.  I would suggest purchasing some other holders to
>avoid this kind of problem.  You should be able to find them well under
>$10 used.

I've used current Fidelity Elite film holders with IR with no problems.
I tried both the current matt surface darkslides and the previous
glossy darkslides (from about 10-15 years ago) and both test fine
after sitting fully exposed to bright sunlight for maybe 15 minutes.
The current Riteway holders with the number wheels are made in the
same factory and of what appear to be the same materials as the
current Lisco and Fidelity holders and should have the same IR blocking
abilities.  I don't know if the bumps on the slide have any real meaning
anymore (maybe rev number of the slide, I should see if the smooth and matt
slides have different number of bumps).

John Sparks

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