Re: IR opaque film holders

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

At 08:26 PM 4/26/97 +0100, you wrote:
>On Sat, 26 Apr 1997 19:07:53 +0100 (WET DST), Russ Rosener wrote:
>
>|most of the holders have these raised dots. However most are wood and a
>|few are plastic. Will this effect the IR film if the holder is wood or
>|plastic?
>
>Plastic is suspect until proven otherwise.  That is, the IR-safety
>depends on the plastic involved.  Wood is suspect, period.  IR has an
>astonishing ability to penetrate wood.  Test the holders you have if
>you want, but expect that probably the Riteway will prove safe, the
>wood holders not.
>
>I keep getting the urge to go back to 4 x 5 HIE, but I wonder whether
>I've kept the sliders with the holders they came with.  The five dots
>presumably refers the the IR-impenetrability of the slider, rather
>than that of the holder; but if that statement is untrue, I'm not sure
>the dots can be relied on to indicate the safety of the holders after
>all these years.  And the same may go for purchased holders:  How do
>you know that those sliders came with those holders?  I guess if
>they're Riteway *and* the sliders have five dots you're safe.
>
>Bob Long
>(boblong@xxxxxxxxxxx)
>

I think there may be confusion over which dots.  There are 5 dots on the
film holder itself indicating safe IR use.  There are also the dots on the
pull tabs of the dark slides which are used only to indicate whether the
film's exposed or not 

Jim Wood


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