And ignoring also the differing degree of enlargement required between the
different formats to get a uniform size print.
--
Piers
-----Original Message-----
From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On Behalf
Of usher99@xxxxxxx
Sent: 27 April 2007 14:31
To: olympus@xxxxxxxxxx
Subject: [OM] Re: DOF question
Hi,
To quote one of Winsor's references, in case there is still a question:
"To maintain the same field of view, the lens focal lengths must be in
proportion to the format sizes. Assuming, for purposes of comparison, that
the 4×5 format is four times the size of 35 mm format, if a 4×5 camera used
a 300 mm lens, a 35 mm camera would need a 75 mm lens for the same field of
view. For the same f-number, the image made with the 35 mm camera would have
four times the DOF of the image made with the 4×5 camera."
Thus ignoring FL and only concentrating on FOV (which is reasonable for
composing the image) a smaller sensor results in a larger DOF at any given
aperture.
Mike (still packing)
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