HMC40 patterned noise and flickering

[Philip Goetz]

Check out these two shots. 1920 x 1080 30p PRORES into FCP7, limit to 10,000kb/sec in compressor, high quality two pass. First shot flickers twice for no reason. Second shot has funny noise in the row of chairs.

DRS was set to two. Auto focus was engaged. When burned to a DVD these shots and the artifacts are way more pronounced.

Whaddyathink?

http://vimeo.com/40900001
password is hmc40

 

[Wesley Byram]

It looks to my eye like aliasing and/or macroblocking, but it's hard to say through Vimeo's compression. First thing's first: is it visible in the original footage straight out of the camera? If so, what were the scene file settings, especially Detail and Vertical Detail?

 

[Wesley Byram]

Just watched it a few more times. It really looks like aliasing. However, the HMC40 doesn't normally do that, so I would be surprised if the artifacts are in your original footage. My guess would be that your NLE is interpreting the 30p footage as 60i and attempting to deinterlace it. That will effectively halve your vertical resolution and introduce aliasing artifacts in the process. Such artifacts are especially visible on horizontal lines like the tops of the chairs in the second shot.

I'm not familiar enough with FCP specifically, but I would imagine that there is a setting somewhere to force import of 30p footage as 30p.