H264 render and export - banding problems

Hi,

I made an edit with source material from a Canon 5D MarkIII. Everything works well, but rendering the clips or exporting the film causes banding problems.

I tried several render setting on export and in the sequence settings. ProRes, Animation, I-Frame only, maximum bitrate, maximum render quality etc.

When the clip runs without rendering, everything looks fine.

When I render or export the clip the banding is visual.

When transcoding a H264 clip from the camera in Quicktime to ProRes 422HQ - no banding. Exporting the same clip from Premiere - banding.

I made similar experience, when transcoding a ProRes 422HQ to H264 with Adobe Media Encoder and Quicktime. Exporting from Quicktime looks much better.

Does anyone have the same problems and perhaps any solution?

Thanks

Frieder

Working on a MacPro 6Core whith AJA Kona 3G, and unfortunately an ATI Graphic card.