Near elimination of prop in videos?

[Buggsy2]

An Ercoupe pilot shows in this video that he can nearly eliminate the annoying prop blur with just a Neutral Density filter over the lens of his camera. How does that work?

[Sam Buchanan]

Originally Posted by Buggsy2

An Ercoupe pilot shows in this video that he can nearly eliminate the annoying prop blur with just a Neutral Density filter over the lens of his camera. How does that work?

The ND filter is reducing the amount of light entering the lens and forcing the camera to slow the shutter speed. This creates a blurred image of the prop instead of the sharp artifacts.

I've seen the same camera behavior when shooting my Drift camera late in the evening on the Legal Eagle. The lower evening light level is not only a wonderful color but causes the prop disc to blur very realistically.

[LAMPSguy]

It is caused by a rolling shutter (think the way your TV scans the image). The pixels in the CMOS sensor are recorded the same way. One sure fire way to eliminate it is to record only with CCD based video cameras that use a global shutter (all at once).

There are drawbacks and positives for both types.

[Sam Buchanan]

Originally Posted by LAMPSguy

It is caused by a rolling shutter (think the way your TV scans the image). The pixels in the CMOS sensor are recorded the same way. One sure fire way to eliminate it is to record only with CCD based video cameras that use a global shutter (all at once).

There are drawbacks and positives for both types.

The original question was why a ND filter will reduce the rolling shutter artifacts.

Yes, a CCD chip is better for videoing aircraft. Unfortunately, all the compact HD point-of-view cameras I've seen use a CMOS chip (GoPro, Drift, Contour, etc). I have a ten year old Canon DV CCD camcorder that records a very nice prop disc. But after shooting a Drift HD camera I just can't go back to standard definition.