HDR Video

try have it for an option on the magic lantern t2i but I haven't really tried it out yet

meh

meant to add that the red epic has a xHDR function and its pretty wild

Epic and Scarlet both do.  The downside is you cut your frame rate ability in half since the camera records two separate streams of video.  The A track records the over exposed side of the track and the X track records the underexposed side of the track. 

The point of it isn't to make it appear oversaturated like a ton of HDR photographs but rather to make it possible to blend the two streams together to for example shoot inside looking out a window and have both properly exposed.  You have the ability to use 1-6 additional stops to get it to work.  I haven't had alot of luck with it when there is alot of movement/motion.  Reason being you get some ghosting since the camera stops down by using shutter speed I beleive.   I could be wrong on that but thats what I remember reading on it. 

I rarely use it except for Timelapses.  I have noticed that I can bring more color into the image though when using it since you can essentially eliminate blacks/highlights clipping.  You use RCX or other software to blend the separate streams together.  I'm pretty sure Premiere enables it as well. 

It's a cool feature but It takes some time to get it just right since you can't see the blended result in camera.  You only see the A track, although sometimes a glitch shows the underexposed side.  I've looked for a way to see both but have been unsuccessful. 

If you want me to we're using it quite a bit in Mexico and I could share an HDR if anyone wants to play with a shot.  For file size though It'll probably be 2K or 3K.

I take it you can only shoot HDR at 60fps? Otherwise you'd just see each exposed film at 15fps? And it'd be jittery?

No,

The Epics frame rates all depend on resolution but, 5K 96, 4K 120, 3K 196 (i think) 2k 300

Scarlet frame rates, 5K 12, 4K 30, 3K 48 and 2K 60

So it just cuts it in half, so on the Epic in 4K your max frame rate in HDR mode would be 60

On the Scarlet your stuck to 15, at 4K momentarily, but they've said there is an update coming at some point which will enable HDR for 4K so maybe 48fps at 4K or some way the camera blends the streams in camera to only record one...not sure.

I use it for timelapses more frequently then anything.