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William LiPera · September 7th, 2005, 08:19 AM

I've noticed that 60i ( worse with 24p) ,16x9 -3db, gamma and color cine footage displayed on a large screen ( 50" plasma and 30" HD tube tv's) at times reveals a grainy, pixelated afterimage(ghost like stutter) on certain detailed images (trees, garss, etc) when panning.It stops once the camera stops moving. This happens with vetical detail low or normal. Is this normal?

A. J. deLange · September 7th, 2005, 08:50 AM

This is normal and very noticeable at 60i if the display is progressive i.e. 30p because two fields taken 1/60th of a second apart are displayed simultaneously. If there is motion and the shutter speed was high enough you will be able to see both images with what looks like a rake hanging off the back end of moving objects. This is the case when video is displayed on computer monitors. With the fancy TV sets it may well be the same but you may have a choice as to scan rate being used. Switch to interlace if possible and the problem should go away with 60i. Otherwize shoot 30p.

With 24p (2:3:3:2 pulldown) the fields sent to the TV are AA BB BC CC DD ... thus you will have the same problem as with 60i but only in 1 frame out of 5. With 2:3 pulldown 1 out of three frames will exhibit this problem. Switching to 60i will eliminate it (though it will still look jerky). Otherwize don't shoot 24p (unless you are transferring to film). If you must, be sure to use 2:3:3:2 pulldown to reduce the effect on a TV set. Low shutter speed makes it less noticeable because the images are blurred.

September 7th, 2005, 08:19 AM	#1
William LiPera Regular Crew Join Date: Oct 2004 Posts: 83	After image I've noticed that 60i ( worse with 24p) ,16x9 -3db, gamma and color cine footage displayed on a large screen ( 50" plasma and 30" HD tube tv's) at times reveals a grainy, pixelated afterimage(ghost like stutter) on certain detailed images (trees, garss, etc) when panning.It stops once the camera stops moving. This happens with vetical detail low or normal. Is this normal?

September 7th, 2005, 08:50 AM	#2
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	This is normal and very noticeable at 60i if the display is progressive i.e. 30p because two fields taken 1/60th of a second apart are displayed simultaneously. If there is motion and the shutter speed was high enough you will be able to see both images with what looks like a rake hanging off the back end of moving objects. This is the case when video is displayed on computer monitors. With the fancy TV sets it may well be the same but you may have a choice as to scan rate being used. Switch to interlace if possible and the problem should go away with 60i. Otherwize shoot 30p. With 24p (2:3:3:2 pulldown) the fields sent to the TV are AA BB BC CC DD ... thus you will have the same problem as with 60i but only in 1 frame out of 5. With 2:3 pulldown 1 out of three frames will exhibit this problem. Switching to 60i will eliminate it (though it will still look jerky). Otherwize don't shoot 24p (unless you are transferring to film). If you must, be sure to use 2:3:3:2 pulldown to reduce the effect on a TV set. Low shutter speed makes it less noticeable because the images are blurred.