What are the correct settings for 2K 2:1 in Mocha?


I am working with digital footage that was originally shot on the RED camera at 2K 2:1 resolution. Each clip came to me encoded in the Apple ProRes 422 codec, with an image size of 2048 by 1024. I need to bring each into Mocha for motion tracking and eventual rig removals & compositing work in After Effects CS4.

I realize that there is some sort of issue with Mocha not being able to import ProRes 422 clips, so my workaround has been to save them out through QuickTime Pro or Compressor as 10 bit uncompressed files or via the Animation codec. They maintain the exact same image dimensions, as well as quality-- just for my tracking purposes.

However, each time I bring them into Mocha, apparently the program automatically interprets the “film back size” (under Clip Settings) as being 35mm VistaVision. The “film back size” comes up with a pixel aspect ratio of 0.75, a width of 1.485, and a height of 0.99. Mocha lists the clip attributes correctly as 2048 by 1024, but the values that are interpreted for the “film back size” make the clip look incorrect when viewing & working inside Mocha. These clips coming into Mocha tend to look more square and anamorphic rather than how wide they look normally when opened in Quicktime Pro.

I find that if I change the “film back size” values in Mocha to Custom, and input 2 for width, and 1 for height (as a Frame Aspect Ratio of 2:1), and set the pixel aspect ratio to 1 (square), then the clip appears to display correctly in Mocha. I tried a track in Mocha and subsequent rig removal with that data in CS4, and everything seemed to be right on.

What are the correct settings for 2K 2:1 footage in Mocha? And what about 2K 16:9? Is it okay to use the custom setting like I’ve described above since there is no specific setting in Mocha for 2K, 3K or 4K? I just want to make sure that my tracking information always matches the original clip when composited back in After Effects CS4.

Working with 2K sized clips is still relatively new to me, so please if you have a better suggestion of how to approach this it would be greatly appreciated.


Mike Konstan

Thank you for the feedback, Ross!

  • Mike

Hi Mike,
What you are doing is absolutely correct. 2:1, square. The film settings in mocha usually get the correct set up from Quicktime imports for standard video preset: NTSC, PAL, 1080 HD, etc.

For film projects (and a good habit in general) it is correct to double check the settings and adjust accordingly.

This is one area that we have identified needs to be improved in next major release: project settings and simplifying the user experience. Your feedback helps.