Re: Larger negatives

Greg Schmitz (gws1@columbia.edu)
Fri, 12 May 1995 17:53:02 -0400 (EDT)

On Sat, 13 May 1995, Virginia Boehm wrote:

> If the sheet of glass is larger than the paper, try weighing the edges
> down with a heavy object to bring it into tighter contact with the
> paper.

It has been my experience that weighting the edges of the glass can
sometimes cause a loss of sharpness rather than a gain because the
glass actually bows, reducing the amount of pressure on the center of
the sandwiched materials. I have found this to be the case with both
thin glass (single lite window glass) and I have noticed bowing when
working with 16x20 inch (aprox) or larger sheets of 1/4" plate glass.

--greg schmitz

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