[meteorite-list] Meteorite Photography
From: Matson, Robert D. <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Wed, 27 Jan 2010 10:44:31 -0800 Message-ID: <7C640E28081AEE4B952F008D1E913F1702A2E4CE_at_0461-its-exmb04.us.saic.com> Hi Eric, Al, Erik, > Erik is right, The higher f-stop of 22 will increase depth of field ... Yes. > ... not sharpness of focus. Unless you have a very good lens, it will ALSO increase sharpness of focus for stationary objects. > This is why sports photographers use a low/large f-stop lens like > f2.8 lenses. (f/2.8 is actually not that fast a lens for a professional. f/1.4 is a fast lens.) > The reason is simple, the smaller aperture only allow focus on a > small area of the subject, blurs out the background and has a > very shallow DOF ... All of these points are true, but that's not the main reason sports photographers use low f/#. In sports photography, short exposure times are crucial so that action isn't blurred. This cannot be achieved at high f/# because the stopped-down lens doesn't let in enough light for a properly exposed image. That said, professional photographers usually do NOT use the fastest f-stop of a lens since the lens periphery has the maximum optical aberrations. An image (of a still object like a meteorite) taken at f/1.4 using an f/1.4 lens will rarely be as crisp as an image taken with the same lens at f/2. Best, Rob Received on Wed 27 Jan 2010 01:44:31 PM PST |
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