… for Adobe Premiere Pro CC
Tip #1302: Surprising Preview Resolutions
Be careful – preview files may not match your source file resolution.
Render file resolution can vary, depending upon two hidden settings. Here’s what you need to know to avoid problems.
According to the Help files for Adobe Premiere:
If your previews are rendered at a resolution below the sequence resolution, the playback resolution is actually a fraction of the preview resolution.
For example, you can set your preview files to render at 1/2 the sequence frame size (1/2 resolution) and your playback resolution to 1/2 resolution. The rendered previews play back at 1/4 of original resolution (assuming that the resolution of the original media matched the sequence resolution).
NOTE: You can set keyboard shortcuts to change the playback resolution.
Not all resolutions are available for all sequence types. For Standard Definition sequences, such as DV, only Full and 1/2 are available. For many HD sequences up to 1080 frame size, Full, 1/2, and 1/4 are available. For sequences with frame sizes larger than 1080, such as RED, more fractional resolutions are available.
This possible resolution difference is why I never use existing preview files when exporting. I always want to be sure exports are at the highest resolution.
Here’s the link to Adobe’s Help for more information.