Unexplicable (to me) focussing problem wuth D7000

[nfpotter]

My second shot there, admittedly not one of my sharpest, is at 1/125.

However, to be safe, a slightly higher shutter sppeed would be better, say 1/250.

1/250 can stop a lot, unless the lens is really long (telephoto).

So, at 1/400 or 1/500 it should stop running action easily.

Maybe birds, with their fast wing rate and long tele required, may require faster, ask one of the birders here.

Cheers
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.....Just from an amateur......'Sometimes it's to your advantage for people to think you're crazy.”

You're confusing camera/lens motion and subject motion, when you're talking about "long telephoto".

The reason to use the 1.5 X focal length minimum shutter speed (unless the lens is stabalized) is to prevent blur from camera/lens motion. It has no bearing on subject motion.

 

[Bajerunner]

Yes, I understand, the telephoto basically magnifies the camera movement on the image, thus why the faster shutter speed is necessary, the longer, the telephoto, even without considering the subject movement.

Thanks
--

.....Just from an amateur......'Sometimes it's to your advantage for people to think you're crazy.”