Framesize you capture is 5120x2560 pixels, a 2:1 aspect ratio
[Anthony DeRose]"2.4.1 - does that mean 2.40?"
Framesize you capture is 5120x2143 pixels.
[Anthony DeRose]"With that what is the best one to shoot at?"
I can not make a comment on what is best. I can only comment on what I like to do. I like to grab the most number of pixels I can, that means I capture the FF 5120 by 2560. If I want a WS aspect ratio I can chop it off in post, but why would I do that in camera? For most 16x9 finishes you end up chopping the sides of the frame, otherwise you have to blowup to fit a 16x9 ratio and that can further degrade the image.
If you know you are going to finish HD then you can (in the latest beta build) capture 5K HD which is a nice 5K mathematical version of 16:9. The advantage here is that there is no reframing and no cropping in post which helps with dailies processing, etc.
If you do capture 2:1 you will have letter boxing in a 16x9 finish. You gain about 14 frames per second in the slow motion department. 5K FF is maxed out at 96 FPS while its 112 in 2:1, I don't see that as a huge advantage.
I think it is best to grab the most amount of pixels and crop later.
If you look at the numbers it's always capturing 5120 wide. By chopping the top and bottom pixels you can get a little more performance but anything other that 5K FF is not capturing the maximum number of pixels the sensor can provide.
I agree wholeheartedly with David, with one caveat. As long as you shoot within your crop limitations. You don't want to get into a situation where you are capturing FF, then in post you decide to crop to WS or 2:1. Unless you shoot a bit loose, you might be limited when reframing shots. Case in point when corporate video was transitioning between 4x3 and 16x9, we would have to (at the clients' requirement) shoot in 16x9 and also knowing that we would be distributing 4x3 for certain deliverables. Was frustrating, as you'd frame up a shot in camera that looked great, then the tech would pop on the 4x3 guides and your framing would have to change to keep action inside the guides.
Just something to be aware of. I'm all for capturing as much data as is feasible. Just keep your guides on your monitor visible!
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