>>I think I get it now (though I don't understand your
equation/formula: 1/f
>>>by (1+M)**2).
To be more clear: Shutter speed to have 40-60% chance of sharp or
slight blur =1/ ((focal length)*(1+M)**2)
(multiple qualifications apply)
One doesn't really have to measure blur, angular velocity for proof of
principle just displacment of the image,
IMO. How about take a 50mm and 100mm prime (macro lenses or zooms are
more complicated as FL may change at close focus) and use extension
only to get 1:2 mag or so--must be the same!!. The 100mm lens will have
more working distance of course. Might be easiest to be sure the tripod
head is level and just move at 5 deg (you pick) in left/rt plane and
assess movement of the target image (target with rulers up down/left
right would be great--must be available to download somewhere). At same
mag, the target image would move much more with teh 100mm lens thus the
same angular velocity of shake would result in more blur which turns
out to be proportional ot the focal length.
Perhaps a proper thought experiment is adequate. Rushing to get home
and perhaps should think more about this b4 posting but wanted to
respond. I haven't cleared this with Dr. Shake yet. Not sure why this
isn't more obviously intuitatively correct. Increase mag will result
in movement across more sensor pixels and thus more blur so perhaps
that is obvious as well as increased angular velocity of shake leading
to more blur.
I am not an engineer or mathematician nor play one on TV though.
Terra Firma, Mike
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