Re: Pyro redevelopment


Liam Lawless (lawless@vignette.freeserve.co.uk)
Sun, 24 Jan 1999 17:42:08 +0000


Hi Hacques,

My densitometer, a MacBeth, is ancient. I don't know how old, but I got a
plaque with it for calibrating. I've had the plaque checked by a
professional dealer, so my densitometer should be as accurate as his!

I don't think small discrepancies are particularly important since, as you
say, we ultimately rely much more on practical tests such as test strips,
but I do think it's important to try and quantify effects such as the one
we've been discussing if we're to talk about them meaningfully. And the
densitometer can also be useful because - to my eye, at least - a density of
1.75 looks much the same as 1.85, but the difference can be significant in
printing (even if the readings are out by 0.02 or 0.03!)

Liam

-----Original Message-----
From: Jacques Augustowski <jacquesa@acd.ufrj.br>
To: alt-photo-process-l@sask.usask.ca <alt-photo-process-l@sask.usask.ca>
Date: 24 January 1999 05:39
Subject: Re: Pyro redevelopment

>I'm following with great interest this thread about Pyro and density
>measurements. How accurate are the readings? Is your densitometer
>calibrated? How sure are you about your measurements? I've had three
>different readings in three different densitometers, all calibrated as per
>manufacturer. With Pyro I just run tests based on trial and error.
>Sometimes measurements can be misleading. Films and developers can be
>changed by the manufacturers, by storage and a myriad of reasons.
>shutters can be more unreliable than the whole processing chain involved
>for making a print. I've spent high bucks on gizmos for film , paper and
>development apparatus. The only one that paid for itself was a shutter
>tester.
>Jacques
>
>



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