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Ron German July 25th, 2009 09:29 AM

CODEC comparison
 
Hi

Is there any reliable comparison about efficiency and, mainly, motion artifacts produced by the H.264 used by 5D MKll and the (MPEG2) HDV from JVC PRO HD (GY-HD 100)?

Thanks
Ron

Daniel Browning July 25th, 2009 11:26 AM

Quote:

Originally Posted by Ron German (Post 1176466)
Hi

Is there any reliable comparison about efficiency and, mainly, motion artifacts produced by the H.264 used by 5D MKll and the (MPEG2) HDV from JVC PRO HD (GY-HD 100)?

Thanks
Ron

The worst artifacts on the 5D2 are caused by aliasing, which in turn is caused by reading only one out of every three lines on the sensor. Unfortunately, aliasing artifacts are very, very hard on codecs and result in a world of compression artifacts (on top of the aliasing artifacts).

The only way to address aliasing artifacts is to soften the image optically so that there is absolutely no sharp detail anywhere in the image. That will prevent aliasing, which will prevent worsened compression artifacts. People are doing this already on accident by shooting thin DOF and missing focus.

Since the JVC cameras don't have aliasing artifacts, the comparison depends entirely on how much aliasing is in the image.

If there is deep DOF with a sharp lens, the 5D2 compression artifacts will be off the charts.

But if the image is soft and has no sharp details, the compression is actually very good IMHO and easily beats HDV.

Ron German July 25th, 2009 12:56 PM

Thank you Daniel

Is there any eletronic sharpness control in 5DMkll to reduce alieasing?
Best regards
Ron

Evan Donn July 25th, 2009 01:06 PM

Yes - you can turn down sharpening in the picture profile which goes a long way towards minimizing aliasing artifacts, although it doesn't eliminate them entirely.

Ron German July 25th, 2009 04:25 PM

Thank you Evan. I`ll see your film.
Ron

Ron German July 25th, 2009 04:57 PM

Evan, where are the artifacts (aliasing and others) in your film?
Did you turn down sharpening in the picture profile? Image is excelent.
How did you edit it?
If this camera had 24p... It shoud be a very good tool for the independent film community.
Maybe the best low cost solution.
By the way: your short is very well made and inteligent.
Ron ver

Evan Donn July 25th, 2009 06:49 PM

Thanks. We didn't end up with much aliasing in that film. if I remember correctly the only place I saw any was in the wide group shots - super wide angle lens (14mm) with plenty of DOF increases the chance of fine detail in the shot. Sharpness was turned all the way down for everything. Personally I haven't encountered any aliasing yet that was so objectionable that I wouldn't use the shot - but I think a lot has to do with the material you're shooting, I may just have been lucky so far. Remember too though that once it's down-scaled to 720p for something like Vimeo most aliasing disappears.

Probably the only visible artifacts we had in that film are in the low light shots where the woman is putting on the hat in the mirror. The close up was shot at 3200 ISO and you can see artifacts in the darker areas of the shot, but that's simply a result of the high ISO noise.


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