Using DOF – example

During the month, I’ll post an occasional image that illustrates the use of focus – this month’s lesson. Today’s is by Joe McNally. If you aren’t familiar with him, you’re missing something.
Clearly, Joe didn’t use Hyperfocal Distance. The subject, Ted Kennedy, would have been lost in the background if he had. Shooting data – 400mm F2.8 – from the presidential convention “cheap seats”. I don’ t know how far these seats were from Teddy but let’s guess 100 feet. Using the On Line DOF calculator from the site provided in lesson #1b (CoC = 0.03 for Joe’s 35mm film camera, f/2.8, 400 mm focal length, distance = 100 feet) we find that the DOF would have been 3.2 feet – pretty shallow at that distance & not possible with a wide-angle lens.
We amateurs can’t afford the Nikon 400 mm, f/2.8 lens that Joe used –  at nearly $9,000 new.  I can’t even afford the f/4 version which would give a DOF increase to 4.5 feet – for a mere $6,100. Fast lenses (low f/number) are expensive, but fast telephoto lens’ prices are out of sight. Nearly $3,000 extra to get one additional stop, from 4 to 2.8, or to reduce DOF 1.5 feet.

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