[pure-silver] Re: Efke 100 buckling

At 5:23 PM -0300 8/24/05, Kevin Halcrow wrote: 
With the all recent interest in Efke films, I'd like to raise a problem
I'm experiencing with my first attempts at enlarging 35mm
negatives of the ISO 100 version. This is a pronounced film
buckling that happens several seconds after my enlarger (Agfa
C66 [= Durst M605]) is switched on. The result is that the initial
sharp focus achieved with the lens wide open is quickly lost. The
degree of buckling is such that stopping down to f11 doesn't bring
the image into adequate focus. I've tried clamping the film more
tightly by putting a slide mount above the frame being enlarged but
this doesn't solve anything. I guess I could work around the
problem by switching on the enlarger with my hand over the lens
until the buckling has stabilized, then make the exposure but this
would be a real nuisance, particularly with split filtering. I don't get
any buckling when I enlarge ISO 25 negatives (or TMax 100). Any
suggestions?

This "popping" is not uncommon with some films with thin substrates. Kodak High Speed Infrared is particularly bad. 120 film typically has a much thicker substrate than 35mm so popping is rarely a problem. The only real solution that I've come up with is a glass negative carrier. You might see if it's possible to fit a piece of heat-proof glass between the light source and the negative carrier.
--

-tony

San Leandro, CA

http://www.shapesandshadows.com
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