Paula wrote:
>I have an F70 which I have been using for
>nearly a year to photograph retrievers at work in the field. Because
>they are often 30-50 metres away, I neeeded more than a 200 mm, so I
>recently invested in a Tokina f4.5 100-400 zoom. I like the lens, and it
>is fairly easy to handle as zooms of that length go, but some of my
>shots are blurred, and I don`t know whether it is through subject motion
>or camera shake. I`m wondering if anybody could suggest a shutter speed
>or shutter speed/aperture combo that might work. These dogs are usually
>on the run, and some of them get going quite fast. Lighting conditions
>are rarely a problem, since the shooting is done outdoors. The guy at
>the camera store advised me to shoot at a shutter speed of one over the
>focal length of the lens, in this case one four-hundredth of a second.
>Will this suffice, or should I go higher?
Paula,
A faster shutter speed will help, but it is not the only, nor is it often
the best solution.
As you speed up your shutter, your lens must open farther to compensate for
the reduced exposure afforded by the faster shutter setting. This reduces
depth of field, and may make it difficult for you to keep the subject in
focus at long distnaces, even with autofocus.
A faster shutter speed will not eliminate motion blur if you move the
camera fast enough, as you might do trying to follow the action or in the
event that you jam down the shutter release trying to capture a quickly
changing scene.
Two things will help: One is a camera rest, such as a monopod (takes some
getting used to, but will improve your photos), the other is learning to
pan with the action while slowly squeezing the shutter release, so you
don't know when the shutter will trip, thus eliminating the 'jam the
button' syndrome. I have instructions on learning to pan with the action on
my web site, under the Tips & Techniques page. You will find it there under
the section on Photojournalism Techniques for All-Manual Cameras. Check it
out, then practice a bit. I think you'll find that it helps.
Best regards,
Stew
--
Photo Web pages: http://www.inficad.com/~gstewart
UNIX: It's not just 'User-Unfriendly', it's 'Proactively User-Hostile'!
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Manual cameras, Luna-Pro's and stick shifts.
