Spinner strobing as a "Bird Strike Countermeasure"
"Mxsmanic" wrote in message
...
Maxwell writes:
Seems I have heard the 16 cps is all that is required for movies to
appear
continuous.
Motion pictures use 24 ips, repeated once, giving 48 fps (24 images shown
twice each). The motion is smooth as long as the image isn't too bright,
large, or fast-moving. Sometimes a stroboscopic effect can be seen in the
latter cases. It can be hidden by allowing image elements to blur.
You can see this effect very clearly on TV (30 ips in the U.S.) when
sporting
events are showing that have been recorded with high shutter rates in the
cameras. Each image is sharp and it's easy to see that a succession of
individual images is being shown on the screen, even at 30 ips.
I think the human eye loosed it around 12 or 13.
Higher than that. Twelve images per second tends to look noticeably
jerky.
Hence the reason an aircraft propeller will
appear to be revolving slowly backwards at times.
Not when being observed directly. That only happens in movies and video
due
to the interaction between the imaging rate and the rotation rate of the
propeller.
Wrong again you clueless twit.
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