RE: ISO of photo paper

A few years ago I picked up an article offering some guidance on paper
'speed' and pinhole photography. I think it was an extract from a
magazine - the author was John Placko, a Senior Photographic Engineer at
Ilford.

He suggested that for Multigrade IV RC Deluxe in daylight an ISO speed
of 1.5 would be about right (ISO 1 under tungsten light).

The warmer colour temperature of daylight at likely sunrise and sunset
results in slower speed (and flatter images) - the reverse being true of
midday exposures.

Papers are designed for exposures up to 100 secs. They recommend
increasing the measured exposure by about 20% for every 1000 secs. Long
exposures decrease contrast by up to half a grade and may require
additional development.

Gary

-----Original Message-----
From: pinhole-discussion-admin@pinhole.com
[mailto:pinhole-discussion-admin@pinhole.com] On Behalf Of Tom von Agner
Sent: 19 January 2002 20:35
To: pinhole-discussion@pinhole.com
Subject: [pinhole-discussion] ISO of photo paper

Hi to all,

Could someone tell me what the approximate ISO of photo paper is? I know
that it's rated in a different form, but what would it be related to
regular
negatives.

Thanks of the help.

Tom

Thompson (Tom) von Agner
Ponta Grossa - PR - BRASIL
E-mail: von-agner@vonart.cjb.net
URL: www.vonart.cjb.net
"Never surrender your dreams
to someone who does not have
your vision or your understanding."

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Received on Sun Jan 20 05:05:50 2002