Re: Problem with Wisner 4x5 camera probably solved!

[George L Smyth <GLSmyth@xxxxxxx>]

Edward Meyers wrote:
> 
> Perhaps tyhe slide was made out of a substance that absorbed
> heat? I just know that the fogging is said to have happened and
> I was told to use the Riteway II holders. Ed

The heat would need to be in the hot-object range (at least arount 250C
(~500F) for that to be the case (reference "Rethinking Infrared
Photography - Dispelling Myths" on my Web page).  Even if it got that
hot, the heat would be transmitted to the other side.  Even if it were
possible to hold the heat on one side, which side would be the side that
was used before exposure?  I keep the dark half facing out before
exposure, then flip to the light half after exposure (that makes sense
to me, although I have a feeling that most people do it the other way).

I think that the point here is that the five bumps on the slide holder
indicate that the slide is IR opaque.  Most slides are fine, some others
(like my Fidelity Elite) are not.

george

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

------------------------------