Since a few years I have had little rigs capable of recording double frame rate videos. More specifically I have a choice of:
- 24/25 p at 24 Mbps
- 50/60p at 28 Mbps
I have since been choosing option 2 with a view of being able to slow motion the footage when required,
Out of the recording I create two files a 25 fps and a 50 fps version.
The 50fps version plays beautifully however even on a powerful quad 3.6 GHz iMac I see dropped frames. The mainstream version is therefore the 25p.
The camera follows the 180 shutter rule at 50p so it shoots at 1/100th this gives videos a bit of a staccato feeling in certain scenes so am now thinking of dropping this to 1/50th although this gives me some challenges at time as the camera smallest aperture is f/11 and lowest ISO 160 (I shoot with a Sony RX100 II).
Slow motions is something I use at times for handheld macro to avoid vomiting when I watch the footage later.
It is a pain to have multiple file formats in the same project so I have so far been shooting in 50p all the times slow motion or not.
For my next trip there won't be any macro so am looking at experimenting I am wondering if I should shoot directly in 25p and forget 50p entirely or if it is actually better to shoot at the highest bitrate. I am aware that the H264 codec uses temporal compression so my assumption was that with the same encoding settings the higher the bitrate the better. I have read somewhere else that instead I should shoot 25p directly as there is more information in each frame however I believe this is not correct as H264 does not store full frames like PRORES or other codecs in fact the decrease in file size when compressing from 50p down to 25p is not great maybe 1-20%.
Am I doing the right thing to shoot at 50p 28 Mbps with a view of producing a 25p file or should I go directly to 25p 24Mbps?
I have done several tests and if I just take a snapshot of a frame I can't see any differences between the two that makes me think that unless I slow down the motion and use the extra frame the two iamges are essentially the same in quality, however if I have a fast moving scene the double frame rate should reduce motion artefacts??
Edited by Interceptor121, 06 May 2014 - 09:52 AM.