Inverse of pulldown — converting 29.97fps material back to true 24fps. Recovers genuine frame rate from NTSC archive footage.
Anyone working with digital archive material shot in NTSC standard knows the problem: the 29.97fps image sequence is artificially generated — created through a pulldown process that converted original 24fps film to video standard. The pullup is the technical reversal of this process. You extract those frames from the sequence that carry the true 24fps information, discard the "duplicates" that were inserted during 3:2 pulldown or 2:2 pulldown — and thereby regain true 24fps material.
In practical application, pullup is needed wherever archive material or transfers from the TV sector are to be integrated into modern productions. A classic scenario: You have 90s video material on Betacam, 29.97fps, but the current production runs at 24fps DCI. Without pullup, you would either have to convert (with quality loss due to frame interpolation) or accept that your archive material runs at the wrong speed. With correct pullup, you regain actual 24fps — information that was already present in the original, just packaged in a redundant NTSC structure. This makes a huge difference in sharpness and motion flow compared to subsequent interpolation.
Technically, pullup is closely linked to the 3:2 pulldown pattern — you need to know which pulldown type was applied. Some archives document this, many do not. Modern software (Resolve, Premiere, as well as specialized archive tools) can automatically detect the pattern, but when in doubt, you have to check frame by frame. A false pullup — i.e., incorrect detection of the pattern — is immediately apparent: flickering, motion artifacts, jitter in pans. Preview is essential.
A pitfall: Pullup is not the same as framerate conversion. With pullup, nothing is recalculated or interpolated — you simply select the correct frames from a redundant sequence. Therefore, the quality is lossless, provided the original 24fps information is actually contained in the 29.97 material. If the material was true 29.97fps video (not a pulldown product), then pullup will not work, and you will need a true conversion.