WHEN in the course of human Events, it becomes necessary….
Floating on the Frame Rate
byVanderleunonJuly 19, 2017
When reviewing the security footage from outside his house in Austin, Texas, Al Brooks spotted an unusual sight: a bird seems to hover past the camera with its wings completely stationary. Of course it wasn’t really hovering (and no, it’s not suspended by strings) but rather the frame rate of the camera matched the flaps of the bird’s wings perfectly resulting in a stroboscopic illusion. This is the same stroboscopic effect you might see in a video of airplane propellers that aren’t moving or when the wheels on a car appear to be frozen.
I would think that either the frame rate and wing flap was the same (1:1 ratio), or a perfectly divided ratio, 2:1, 3:1, or 1:3, 1:2, etc. That would create the same effect. Pretty cool regardless.
Anybody remember old cowboy movies where the stage coaches were being chased by bad guys and the wheels appeared to be rotating backward? I was just a kid when my Dad tried to explain the sample rate to me, but it did not jell until electronics school.
Phil in EnglewoodJuly 19, 2017, 3:45 PM
This video demonstrating/explaining rolling shutter is pretty good, too. The odd video of airplane propellers starting about 2:00 is particularly interesting.
The shattered water made a misty din.
Great waves looked over others coming in,
And thought of doing something to the shore
That water never did to land before.
The clouds were low and hairy in the skies,
Like locks blown forward in the gleam of eyes.
You could not tell, and yet it looked as if
The shore was lucky in being backed by cliff,
The cliff in being backed by continent;
It looked as if a night of dark intent
Was coming, and not only a night, an age.
Someone had better be prepared for rage.
There would be more than ocean-water broken
Before God’s last Put out the light was spoken.
Bright blooms of flame spattered shadows on that tide
Whose strangling fingers clawed into our lands,
And scraped out slots, fresh graves upon our sands.
A far-off signal flared and sputtering fell,
Its bloom of sparks erupting deep in slate,
But, like our last edition, this signal came too late.
The drumming bursts of broken cannons
Stomped along the edges of our gilded cage,
And faded like the lies we smeared on our front page,
Faded until all we heard of want or wish or war
Were the screams of our grandchildren slain
Beyond our gilded sand, upon our once fruited plain.
I CELEBRATE myself, and sing myself,
And what I assume you shall assume,
For every atom belonging to me as good belongs to you.
I loafe and invite my soul,
I lean and loafe at my ease observing a spear of summer grass.
My tongue, every atom of my blood, form’d from this soil, this
air,
Born here of parents born here from parents the same, and their
parents the same,
I, now thirty-seven years old in perfect health begin,
Hoping to cease not till death.
— Walt Whitman
Still LIfe with Stick and Word
April is over. May moon.
How many more for my regard,
hundreds, a handful?
Better not trouble the dark water due north of north.
Better to concentrate on something close, something small.
This stick, for instance. This word.
“From a student radical/hippie/leftist of the Free Speech Movement/Vietnam Day Commitee era and a full-on Democratic Liberal in the decades after, I think I’ve evolved a politics that is neither right nor left but is, in its elemental nature, draconian. In the last 20 years, I’ve taken apart my beliefs with a sledgehammer. Now I’ve got to put the surviving parts back together with tweezers and other ‘shabby equipment, always deteriorating’.”
Real World Address for Donations, Mash Notes and Hate Mail
Gerard Van der Leun
1692 MANGROVE AVE
APT 379
Chico, Ca 95926
When reviewing the security footage from outside his house in Austin, Texas, Al Brooks spotted an unusual sight: a bird seems to hover past the camera with its wings completely stationary. Of course it wasn’t really hovering (and no, it’s not suspended by strings) but rather the frame rate of the camera matched the flaps of the bird’s wings perfectly resulting in a stroboscopic illusion. This is the same stroboscopic effect you might see in a video of airplane propellers that aren’t moving or when the wheels on a car appear to be frozen.
Gerard Van der Leun
April is over. May moon.
Comments on this entry are closed.
I would think that either the frame rate and wing flap was the same (1:1 ratio), or a perfectly divided ratio, 2:1, 3:1, or 1:3, 1:2, etc. That would create the same effect. Pretty cool regardless.
Anybody remember old cowboy movies where the stage coaches were being chased by bad guys and the wheels appeared to be rotating backward? I was just a kid when my Dad tried to explain the sample rate to me, but it did not jell until electronics school.
This video demonstrating/explaining rolling shutter is pretty good, too. The odd video of airplane propellers starting about 2:00 is particularly interesting.
https://youtu.be/dNVtMmLlnoE