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Posted (edited)

THE VINTAGE AVIATOR AIRSHOW

............Hood Aerodrome New Zealand 24 April 2010...........

 

The "Vintage Aviator Airshow" Part 1 - 3 can be watched in HD - do so and enjoy close looks at beautiful craft.

 

Part 2] Albatros D.Va flight and close-ups; Tiger Moth; Fokker Dr.1 Staffel flight and close-ups;

Farman FE2b; Scout Experimental S.E.5a cockpit and flight

 

Edited by Olham
Posted

Thanks, Olham! Any one notice how slow those props rotate on most of the planes.. I had never thought about it, but the engine RPS really weren't very fast.

Posted

Thanks, Olham! Any one notice how slow those props rotate on most of the planes.. I had never thought about it, but the engine RPS really weren't very fast.

 

That's true, they weren't very fast. But this effect can also be caused by the video capture fraps.

If a four-blade propellor makes a quarter turn, a half turn or a full turn from one frame to the next, it would appear like standing still.

If it made 1/8 of a turn from one frame to the other, it would appear like turning slower than it actually does. Etc.

Hope it makes sense? I'm dizzy now!

stars.gif

Posted

Yep you cannot judge the speed of the wheels or spinning objects easily from movies due to the fact 1 second of movie is actually made up of many still frames (how many depending on the format). As Olham says take a frame snapshot, now take another 1/24th of a sec later - the prop may have spun around more than a full circle like 370 degrees, but when you show the 2 frames it looks like it only moved 10 degrees in frame #2 because it's only 10 degrees on from frame #1. So during playback this is the same for each frame at that prop speedm it will appear to go much slower.

 

It may even not do a full revolution maybe 350 degrees per frame now it will appear to be going backwards instead.

 

That's why wheels and props often appear to spin in reverse on movies, and in games or change direction.

Posted

Yep you cannot judge the speed of the wheels or spinning objects easily from movies due to the fact 1 second of movie is actually made up of many still frames (how many depending on the format). As Olham says take a frame snapshot, now take another 1/24th of a sec later - the prop may have spun around more than a full circle like 370 degrees, but when you show the 2 frames it looks like it only moved 10 degrees in frame #2 because it's only 10 degrees on from frame #1. So during playback this is the same for each frame at that prop speedm it will appear to go much slower.

 

It may even not do a full revolution maybe 350 degrees per frame now it will appear to be going backwards instead.

 

That's why wheels and props often appear to spin in reverse on movies, and in games or change direction.

 

I didn't even think about that, you're right, and I've seen that before where wheels seem to be turning in the opposite direction.

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