5d3 60P with MLV

[5D3shooter]

Yesterday I was going to shoot some footage in 720p 60P but when I try to select 1280x720 in MLV settings the settings keep going to 1280x448 and says I have to stretch the video.  My card is definitely fast enough to do 1280x720 because I've done it before on an older build.  How do I make it go back to 1280x720?

[NedB]

@5D3shooter: I may be mistaken as I do not own a 5dIII myself, but my understanding of ML raw in general is that it derives from whatever is presented to LiveView, and apparently when shooting 50p/60p, the data presented to LiveView is anamorphic, with a ratio of between 1.4 and 1.6 or so, depending on the camera model. ML takes this into account, which is why it will only let you select the anamorphic 1280x448 ratio when the Canon menu is set to shoot 50p/60p. I don't think you could have shot 1280x720 in an older build, at least not at a 16x9 ratio. By the way, this is why the aliasing is apparently worse in 50p/60p mode, because whatever process Canon uses to lower the resolution from stills resolution to video (whether it's line-skipping, as in the older models, or pixel-binning, as in the 5d3), the process is exaggerated for the anamorphic mode. Not sure whether this applies to the 5d3, because aliasing in 24/25/30p mode seems to be almost non-existent for that camera, but for the other cams, it's worse. If anyone else knows different, please chime in!

Short answer: you're not doing anything wrong, but right now you can't shoot 50/60p non-anamorphically. Cheers!

[ted ramasola]

even on the 7D 60P mode(50fps only is possible on 7D) the image needs to be stretched vertically in post. Quality is not good due to aliasing.
See my post here:
http://www.magiclantern.fm/forum/index.php?topic=10195.msg98252#msg98252