Realistic video resolutions and DSLR's.....

[nateo200]

What is preventing an 18megapixel DSLR like a Canon 7D or 550D from shooting video higher than 2megapixels (1920x1080p)? I mean I understand the obvious ones being the fact that your bitrate goes up and is bottlenecked at the SDXC cards speed, your CMOS sensor begging for mercy, the fact that canon probably doesn't really think anyone needs to shoot 2k+ on a DSLR (and they are probably right!), etc. But lets talk theoretically here; Could the current line up of DSLR's realistically shoot say 2.5k video natively with a fast SDXC card, more battery life, ect.? I mean the video portion uses such a small portion of the overall megapixels/sensor...I figured this would be an interesting discussion for some and as I've been playing ALLOT more with video now I can't help but wonder. The purpose of the discussion/idea isn't "Well you don't need that much resolution" rather "Bigger and better? Oh yeah because I can!".

[edDV]

What is preventing an 18megapixel DSLR like a Canon 7D or 550D from shooting video higher than 2megapixels (1920x1080p)? I mean I understand the obvious ones being the fact that your bitrate goes up and is bottlenecked at the SDXC cards speed, your CMOS sensor begging for mercy, the fact that canon probably doesn't really think anyone needs to shoot 2k+ on a DSLR (and they are probably right!), etc. But lets talk theoretically here; Could the current line up of DSLR's realistically shoot say 2.5k video natively with a fast SDXC card, more battery life, ect.? I mean the video portion uses such a small portion of the overall megapixels/sensor...I figured this would be an interesting discussion for some and as I've been playing ALLOT more with video now I can't help but wonder. The purpose of the discussion/idea isn't "Well you don't need that much resolution" rather "Bigger and better? Oh yeah because I can!".

The current sensors and processors can't update at video rates with 4-6x the pixels to process. The raw files would be enormous. Affordable camera chipsets only handle 1920x1080 video encoding.

If you wanted a camera to shoot > 1080p, you would need to build a Red Scarlet using similar parts. Like Scarlet, it would need to shoot to a custom digital intermediate. The result would make a poor still cam.

[magillagorilla]

Yup, It's not all about pixel count. Even "good" DSLRs suffer from rolling shutter problems (insuficient refresh rate) and data bottlenecks at 1080 30/24p. Plus crunching that 1080 video down to 17-20mbps on the fly represents a decent level of processing power.

I'm sure in a couple DSLR generations you may see 2K video capabilities. For now I'd be pleased if my Nikon could shoot 1080 60p instead of 1080 24p. You'd probabely need at least 30-40mbps in some h.264 container for 2K video to look decent. That's likely on the edge of the constant write speed of SD cards.

When I can get 2K video in my hand for under $2K I'll go for it.