Archived posting to the Leica Users Group, 2000/08/07

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Subject: Re: [Leica] Shadow boxing (more from Ansel)
From: Mark Rabiner <mark@rabiner.cncoffice.com>
Date: Mon, 07 Aug 2000 22:36:05 -0700
References: <Pine.NEB.4.21.0008071326320.15965-100000@panix2.panix.com> <v04011700b5b5224575dd@[209.53.32.129]>

0	I	II	III	IV	V	VI	VII	VIII
.5	1	2	4	8	16	32	64	128	Image units
2	2	2	2	2	2	2	2	2	Flare units
_______________________________________________
2.5	3	4	6	10	18	34	66	130	Total units

From zone V up the effect is so slight as to be practically negligible.
Considering shadow values as representing zones to III, we see that the contrast
ranges given by the coated and uncoated lenses within these zones are:
Coated lens: 1 to 8
Uncoated lens: 1 to 24
Obviously, the shadows will be "snappier" with the coated lens.

Now we have shown the contrast differences in the shadow are of the scale: what
are the differences in contrast over the entire scale-from Zone 0 to Zone VIII?
They are:
Coated lens: 1 to 256
Uncoated lens: 1 to 50 (approx.)



the above all from  Ansel Adams: The Negative Basic Photo Two 5th printing.

Mark Rabiner
He says later its a much bigger deal with small film sizes or very large
enlargements than with regular large format.
Notice his use of one of my favorite key scientific optical terms: "snappier"!

In reply to: Message from Edward Meyers <aghalide@panix.com> (Re: [Leica] in the dark with the summilux)
Message from "Henning J. Wulff" <henningw@archiphoto.com> (Re: [Leica] Shadow boxing)