Aircraft propeller blur - how to?

[freybear3]

What settings should I use, to get a propeller to blur on an airplane?

[i speak in math]

Originally Posted by freybear3

What settings should I use, to get a propeller to blur on an airplane?

Anything slower than the angular velocity of the tip of the propeller.

[Digidave]

Originally Posted by i speak in math

Anything slower than the angular velocity of the tip of the propeller.

[i speak in math]

Lets say the propeller with a length 3 feet is spinning at 2400 rpm. The tip is moving the fastest so if we want to freeze the motion of the propeller, we would have to freeze the tip as well. With a radius of 3 feet, we are talking about a circumference of 6pi or 18.85ft. At 2400rpm, that is a velocity of 45240 ft/m or 754ft/sec. That works out to 9048 in/sec. Freezing the tip of the blade would occur generously at 2 inch or so of movement at the tip? So, we need a shutter speed that results in only showing that much travel. Using a proportion, 9048in/1sec = 2in/xsec = 1/5000 sec. So if we want to freeze the motion of the propeller, something faster than 1/5000 sec should get close. If we want it blurred, anything slower than that will work. The slower the shutter speed, the more blur you get.

[Digidave]

The slower the shutter speed, the more blur you get.

Whew!! It took you an entire paragraph but you finally managed to say something I could comprehend.

Actually, I understood everything. I just couldn't let this pass without giving you a little bit of crap, Mr. I-Speak-in-Math. I understand most mathematical concepts but am never able to put them into layman's terms as eloquently as you have. I'm impressed!

[OsmosisStudios]

Originally Posted by i speak in math

Anything slower than the angular velocity of the tip of the propeller.

I chuckled. It made sense to me: i just wasnt wearing my engineering cap so I wasnt about to go spouting off numbers and equations.