Re: [Rollei] Re: Film Flatness

[Richard Lahrson <tripspud >]

Tim Ellestad wrote: 
> Mannheim talks about this in his book on the SL66.  He describes a test you
> can do by advancing a frame, quick pulling the magazine and dark slide and
> watching the mirror reflection of something like venetian blinds on the
> emulsion surface.  In about 30 seconds the film will likely "relax", giving
> up it's flatness.  Cameras with contorted film paths like SL66's, Hassy's,
> etc. have the greatest trouble with this, but a friend of mine who is an
> architectural specialist has had a fair amount of this trouble with rollfilm
> magazines that he uses with his 4x5 Sinar.

Hi,

     For roll backs (I"ve got a Graflex roll back that doubles back like
the Hasselblad, Mamiya 67, Mamiya 645 and Bronicas) you can feel the bulge
in a darkroom.  It seems to "take the bulge" at the point where the film
bends 180 degrees.  So, if left unused for awhile in the camera, the film
will bulge on the exposure after the one that's ready to fire.

					Rich Lahrson
					tripspud  

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

End of Rollei Users list digest V2 #32
**************************************