Note: This also works for 60p footage.
Normally cameras have 50i. One of the first cameras recording in 50p were the 700 and 900 series from Panasonic. But earlier Adobe versions does not provide a 50p sequence preset. That’s not a problem at all. Just use the 25p preset and your good to go.
As you can see the CS6 does also have a preset for 50p. But since most movies for cinema and the internet still have to be 24/25p you should go with the 25p version. The speed of the clips in the timeline will be correct. But the best part about using a 25p-sequence is the amount of CPU and GPU power you can save.
Save CPU and GPU time by using 25p sequences
The comparison shows clearly the benefit of the 25p version. The Cpu usage in 25p playback is only 60%(approximately) of the usage in 50p. With a CPU based effect like anti alliasing you can see how double framerate will stress your CPU during playback. We can see even better results when looking on the Gpu usage: in 25p the Gpu needs 3% of its calculating power to playback the footage. The 50p sequence needs 12%. Just imagine you apply some effects to the clips and you will see how the 50p version starts to lag way earlier.
A short 50p clip with color curves, black&white and gaussian blur shows the difference. The 50p version needs nearly 7-time the gpu power than the 25p version.
Remember: the footage is still the same and looks the same in adobe preview playback. So why lets adobe show and calculate 50 frames to you if you can’t see them anyway? If you don’t need to export the footage in 50p later, you should stick to the 25p-sequenz.
Export as always
To export the material you can use the presets from adobe or create an own one. Just use the 25p option for all video format because interlacing would screw the benefits of the progressive format. For most of the internet video platforms h264 in 720p25p with 5-8 Mbit is perfect. Of cause this depends on the footage.
Used system and details
Adobe Premiere Pro (CS6) with a CUDA supported card was used. To measure the CPU and GPU usage MSI Afterburner and the windows task-manger were used.
CPU: Phenom X4 965 @2,2ghz (up to 3,4ghz)
GPU: gforce gtx 460 with Cuda
Ram: 8 gb - 1300
The test file was footage from a TM700, recorded with 1080p50p and 24MBit.
