VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #1  
Old 09-13-2012, 12:24 PM
Buggsy2's Avatar
Buggsy2 Buggsy2 is offline
 
Join Date: Jul 2008
Location: NorCal
Posts: 565
Default Near elimination of prop in videos?

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?
__________________
Ralph Finch
RV-9A QB-SA
Davis, CA
Reply With Quote
  #2  
Old 09-13-2012, 02:16 PM
Sam Buchanan's Avatar
Sam Buchanan Sam Buchanan is offline
been here awhile
 
Join Date: Dec 2004
Location: North Alabama
Posts: 4,462
Default

Quote:
Originally Posted by Buggsy2 View Post
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.
__________________
Sam Buchanan
RV-6
Reply With Quote
  #3  
Old 09-13-2012, 03:21 PM
LAMPSguy's Avatar
LAMPSguy LAMPSguy is offline
 
Join Date: Feb 2008
Location: Pensacola, FL
Posts: 377
Default Rolling Shutter

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.
__________________
RV-15 in planning stages.
RV-7 shared.
RV-14 #140050 SOLD

Permanently willing to contribute fuel for RV rides

Helicopter ATP/CFI(I)
ASEL/Glider Commercial/Inst/CFI(I)
AMEL ATP
Aerobatic Enthusiast
Enjoying flying the 747 around the world.
Atlanta based.
Reply With Quote
  #4  
Old 09-13-2012, 09:33 PM
Sam Buchanan's Avatar
Sam Buchanan Sam Buchanan is offline
been here awhile
 
Join Date: Dec 2004
Location: North Alabama
Posts: 4,462
Default

Quote:
Originally Posted by LAMPSguy View Post
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.
__________________
Sam Buchanan
RV-6

Last edited by Sam Buchanan : 09-13-2012 at 09:36 PM.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 05:12 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.