Re: Outdated Material

[Ken Sinclair <photo1@xxxxxxxxxxxxxxx>]

Jim
Having used large format film holders for some 40 years, I have regarded
the raised  dots on the dark slides to be an indicator as to whether the
film had been exposed or not.
If you look at recent Fidelity film holders, the darkslide has 8 dots that
the fingers "feel" that the the film (assuming that the darkslide was
inserted according to "convention") has not been exposed. I hold no truck
with the idea that the raised dots are there to indicate IR "safeness" or
not. My Linhof holders seem to depart from "convention" in that do not have
raised dots but a 7.5 mm serration that you have to feel for to indicate
the exposed side.
I have used filmholders with 5, 7, and 8 dots on the darkslide, and since I
would not now use old wooden filmholders for IR sensitive materials (I was
burned once), I would rather rely on a personal test for each filmholder
that the continuing myth about the dot "number" being indicative of a IR
safe/non IR safe film holder.

While wearing nitrile gloves, cut a sheet of film into 1 inch squares,
gently and lightly, scratch the film holder into the emulsion with the
sharper "pointy" blade of a smaller pair of scissors and tape them inside
each film holder. Take them outside and expose to the sunlight and expose
without removing the darkslide. Hold back one square in the darkroom or one
filmholder as a control.

Ken

>I do have a question about film holders and IR.  I have reservations about
>the comments that film holders with five dots on the holder (not the dark
>slide) are IR safe. My 4x5 film holders have five dots and are IR safe.
>However, I have a batch of old Lisco Regal 5x7 film holders also with said
>five dots.  I have never heard of IR film in that size and wonder why they
>so marked and whether they are IR safe.

[||/\/\/\/\/\/\||      Ken Sinclair RBP,FBPA
[||                            ||-|   Applied Photographic Services
[||                            ||  |  Lethbridge,
[||                            ||  |  Alberta, Canada,
[||                            ||-|   (403)381-1654.
[||\/\/\/\/\/\/||      photo1@xxxxxxxxxxxxxxx
_0___________0______
|__________________ |
                O


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End of Infrared-Digest V0 #664
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