Re: infra-reference list

[George L Smyth <GLSmyth@xxxxxxx>]

On 10 Jun 97 at 14:16, Bill Franson wrote:

> On a purely practical note
>though, couldn't we create a list of equipment that has already been
>tested by members of this list as being "safe"?  Perhaps a shorter (?)
>list would be one of items known to be "unsafe".

Why not go to the FAQ?  Possibly because it has been hard to reach (I am
looking to get permission to mirror it on my Web page - currently I have
a link to it).  Anyway, below is some text from the FAQ.

george

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   Not all cameras are appropriate for Kodak IR film use. The other
films
   are less sensitive to IR and have an anti-halo layer so they have
   less, if any, problems.
   
   For instance, the Canon EOS models which have an IR optical film
   loading mechanism (eg Elan/100, A2E/5 but okay in 10s/10 and older
   models) fog part of the negative.
   
   [About 4 mm. So you will get a frame that is 20mm x 36mm. The 4mm is
   in the bottom of the image (top of the film in the camera). (source:
a
   posting in rec.photo (by Vangelis Tziampazis ?))]
   
   But Mircea Podar (podar@xxxxxxxxxxxxxx) says:
   I own an EOS A2 and for the couple of years I had it, I kept
   regretting that I cannot use infrared on it, according to Cannon.
   Recently I found on the news that only ~ 1/4th of the frame gets
   fogged, so I decided to give it a try. Guess what, the ONLY area that
   turned black from the IR film tracking system was the holed strip and
   there was NO fogging on the actual film frame!
   I used the Kodak High Speed IR (Black & White).
   
                         negative from an EOS 5/A2 
               Negative shooted and scanned by Mircea Podar.
                                      
   A previous version of this FAQ said: "Also some camera backs may not
   be opaque to IR, especially some plastics." No one reported a single
   case of this happening. For instance, W.J.MARKERINK comments:
   "FWIW: I have used all sorts of IR film in my EOS-1....yes, it has a
   plastic back, and yes, it has a film window. And no, it works fine,
   perfectly fine."
   
   On the other hand, some pressure plates do cause problems with the
   Kodak HIE film. The problem is the lack of the anti-halo layer. This
   allows light reflected by the pressure plate (which is usually black,
   but not mate) to impress the film. This creates the hazy higlights
for
   which this film is know.
   
   I have read about the Pentax LX or K1000 dimpled pressure plate
   creating a pattern on the Kodak film (because of the dimples).
   Also some early Minoltas had the same pressure plate for the models
   with or without databack. The hole in that pressure plate produces a
   visible effect on HIE film. Markerink says:
   Cameras that are partly unsuitable for IR, Kodak HIE only, are [...]
   cameras with dimpled pressure plates, like the Pentax K-1000 [...],
   and (Minolta) cameras with pre-installed databack pressure plates,
   like early 9xi's and all 700si's.

- -- 
 Handmade Photographic Images     
  http://www2.ari.net/glsmyth/
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