Originally posted by Rondec The 1/focal length equation seems to me to break down at wider angles. I don't care what anyone says. It isn't easy to hand hold for 1/16 of a second, even if you are shooting at 16 mm (depending on the situation).
I think you've misunderstood the guideline. The guideline - that you should not use a shutter speed that's slower than 1/focal length - is a guideline intended simply to limit your shutter speed. It's designed to advise the photographer shooting at, say, 200mm, NOT to use a shutter speed slower than 1/200th sec. The guideline is NOT intended to say that it is a good idea to use any shutter speed that is faster than 1/focal length!!
There is an absolute limit to how slow the shutter speed can get if you're holding the camera in your hands. I don't mean to invite disagreement ("I can do better!") but it's somewhere in the vicinity of 1/30th sec or 1/20th sec, and that's WITH shake reduction. And for many photographers, even 1/30th sec may be too slow, even if the shutter speed is very wide. So even if you're shooting a building on a calm day, at a focal length of, say, 18mm, you're not going to want to go slower than 1/30th sec, unless you're a Man of Steel.
And if you're shooting people or animals or flowers blowing in the breeze - anything that moves - then you have to worry about subject movement, and that provides a further constraint on how slow your shutter speed can go.
TO restate what I said earlier: What this means in the present context is, at wider focal lengths, shake reduction becomes less valuable. If you have good technique, you do not really need shake reduction in your lens or camera to take a decent shot with a focal length of, say, 28mm and a shutter speed of 1/60th sec. If you have really good technique, you might be able to go down to 1/30th sec - assuming that the subject isn't moving. Since an awful lot of the prime lenses for other brands of camera (as for Pentax) are for focal lengths less than 80mm, the need for VR or IS in those lenses is less urgent than a Pentax shooter might think.
Or to put it differently: shake reduction does more for us Pentax photographers when we're shooting at 200mm than it does when we're shooting at 20mm, at least most of the time.
Quote: Obviously SR is much more useful for static things anyway, so talking about it in terms of shooting moving objects is not worthwhile.
You lost me there. There are THREE ways for an image to be blurred: 1, camera's out of focus; 2, subject is moving and the shutter speed is too slow to stop the subject's movement; and 3, the camera is moving (and the shutter speed is too slow and/or shake reduction is inadequate to counteract the movement).
It's possible for an image to be damaged by all three of these problems at the same time. Not all subject movement requires speeds of 1/500th sec! A toddler taking its first steps might be photographed at 1/60th sec. If you're shooting from across the room with a 70mm lens, you'll benefit from shake reduction. Moving does not have to mean "moving fast." When I'm shooting a wedding ceremony and I'm locked on the bride's face at 1/30th sec, I'm really hoping she doesn't turn her head just at the moment I click the shutter.
Will