Thoughts on Object Motion and the 7d

U

ulysseshead

Member
So I'm gonna throw this topic out there as I haven't been able to find any others' comments on the subject. I love the camera (upgrading from 10d—which has been a mind blow for my stills). My former vid rig was XHA1 with a Redrock, moving to the 7d and understanding there would limitations with the DSLR. But what's getting me is that the motion of objects, people in particular, doesn't look as fluid as dedicated video cameras, let alone film. A lot of what I'm seeing looks slightly overcranked, so there's a staccato thing happening. I'm mostly seeing in it in 24p. And it doesn't seem to be consistent either. Below are a couple examples videos, very well shot from vimeo.

Example #1
http://vimeo.com/8182846 at 3:20, the woman weaving the basket.
Don't her fingers look a little over cranked there? I'm assuming the photographer was shooting with a 180 degree frame rate as it doesn't look really overcranked (and other parts of the video look fine). Just something about the movement of her fingers doesn't look smooth. I've seen this in lots of places as well as my own test footage.

Example #2
http://vimeo.com/6806678
The 24p stuff here looks smoother to me, though at times I still feel like I'm seeing that staccato motion, just much less than above example.

I was wondering if it's happening because we're not getting a true 180 degree shutter, having to set the frame rate at 50, not 48. But I found Barry's post that 180 shutter is actually a fairly relative number and varies quite a bit even in film cameras. So what gives? It doesn't seem to be bothering anyone really, including all the fantastic photographers out there much more talented than I. But man, it's just buggin' me.

Anyone see this? Care to comment? Would love to hear other's impressions.

Thanks!
Lance
 
Most likely it is due to the shutter speed being set substantially higher than 1/50th of a second for 24p, or 1/60th of a second for 30p. This is quite common when shooting outdoors at wide apertures since the dslr line of cameras are not equipped with built in ND filters. People tend to compensate for over exposure by cranking up the shutter speed.
 
Vimeo is glitching on me, but the gyst of it is that sometimes it actually is a higher shutterspeed you're seeing in these clips. The reason being, more than likely, the shooter had to make a choice between Stop and Shutter Speed and they chose shutter speed instead.

NDs and Polas correct this, as well as lighting.

Otherwise, I haven't really had an issue with what you're describing. I do see it ALL the time in other people's footage, and I'm pretty sure that's what it is.

If you own a 7D, try using a 1/45 shutter and see how that sings to you. I've been doing that and I'm happy with it. 1/50 and 1/45 are both close enough to 1/48.

The real issue is not being able to get rid of scrolling lines with fluorescent lighting. =(
 
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