copy negatives

Paul Simon (70760.1511@compuserve.com)
14 Sep 95 00:50:24 EDT

I've been away for about a week and a half on vacation, but I
see that before and after that time, there have been a number of
notes about making enlarged copy negatives. It's of great
interest to me, as I have several decades of 35 mm black and
white that I want to go through and make a few pt prints. The
problem I have with all the discussions is that no one seems to
be addressing the issue of fidelity of transfer. I have been
looking at Agfa N31P as sold by Palladio, and using a
densitometer, find that it is quite linear at gamma =1 above a
density of about 0.5. I have not yet checked at higher gamma but
suspect similar results. The instructions in the Palladio manual
for using this stuff are pretty good but semi-quantitative. It
would seem that to get a useful, linear transfer with this
material would cause one to suffer about a 4 times exposure
penalty therefore, by being forced to stay about .6 above B+F.

Does anyone have densitometric data on other copy processes? Is
it important/significant enough to worry about? Comments?

Paul Simon