Jerky footage with 1DMK4

[Trevor Dennis]

I have started using my 1DMK4 for video, and am getting a sort of jerky stutter in any shots with movement, (like tracking shots). I can see it in the .MOV files right out of the camera, so it is not a Premiere Pro issue. Any ideas what I am doing wrong?

[Justin Molush]

Whats your shutter speed at?

[Trevor Dennis]

I used Av and various apertures, but don't know what shutter speed the camera selected. I would guess that the shutter speed would have been pretty high for some clips >1000th for instance. Are you thinking that I should use a slower shutter speed? And is there a way I can check what the shutter speed was from the video file properties? It's all way too complicated compared to stills. :-(

[Jerry Porter]

That's your problem, if you are shooting at 25fps your shutter needs to be set at 50. if you are shooting a 50fps your shutter needs to be 100. Always try to get the shutter at 180 degrees.

[Robert Turchick]

Second the shutter speed. Though that generally shows up as a strobing, unnatural motion that's pretty consistent. If its more of a stutter that randomly shows up, it could be the playback on your computer. If I have a 1080p video playing full screen it tends to be jerky. Shrinking to half cures it. (time for a new video card!)

[Jerry Porter]

Hey Robert,
He said that he was letting the camera pick the shutter speed so it could be all over the place and then only showing up when it jumps up to make up for other exposure issues. I'm of the mind set that you should only shoot video with Canon DSLRs in full manual mode.

[Justin Molush]

Yep - echoing all the above.

When shooting DSLR video you should choose your shutter speed (always 180* unless you have a reason otherwise - and there are valid reasons to ramp the shutter), then choose your aperture, and then choose your ISO. If your still overexposed, time for NDs.

I figured out very quickly that to keep DSLR footage looking nice in the middle of the day and not heavily diffracted you NEED NDs since shooting at large apertures is usually the reason to shoot on DSLR anyway (at least in my opinion).

[Trevor Dennis]

Thanks for your help guys. I think it must be the shutter speed because I wondered about the computer not keeping up, so I exported one of the worst clips to view on my TV, and it was exactly the same.

My only ND is an 8 stop Formatt/Hitech i use for stills, and that is far too much. I also have one of those variable NDs, but it is the Chinese knock-off (not the Singh Ray) and it does nasty things to colours and causes vignettes. I'll see how I get on with a CPF.

[Robert Turchick]

Originally Posted by Jerry Porter

Hey Robert,
He said that he was letting the camera pick the shutter speed so it could be all over the place and then only showing up when it jumps up to make up for other exposure issues. I'm of the mind set that you should only shoot video with Canon DSLRs in full manual mode.

Understood but without an example gotta cover all possibilities. :). And I always shoot manual too.

[Trevor Dennis]

I've now had a chance to try some close-up tracking shots at 1/50th, and they are _much_ better. Thanks for your help.

[Jon Fairhurst]

Getting the shutter speed right is important. Also be aware of the maximum, recommended panning speed, according to the ASC. It works out to about 7 second from one edge of the screen to the other. That's *really* slow.

As it turns out, you can pan quickly (aside from the jello it causes on DSLRs), or you can pan slowly, as the ASC recommends. When it's fast, the pan is over before you notice the stuttering. When it's slow the judder is acceptable. It's that mid-speed that is a problem.

That said, you can often get away with a mid speed pan when tracking the object of interest. The audience looks at the shiny object and doesn't notice that the background is juddering. You, as the shooter, might notice it because you will be more critical of your own work, and you will watch the scene over and over while out of context. The audience is (hopefully) into your story and will only see the tracking shot once. In that situation, they are unlikely to be conscious of the judder - assuming a 1/50th shutter speed and a story that holds their interest. ;)

[Steve Maller]

The "jerkiness" may not be the shutter speed at all. In my experience, when the aperture changes whilst shooting video, it's a very abrupt change, and looks bad in the file. I'd never use anything other than 'M' for manual on any DSLR. This is one of the main advantages of a true video lens, as opposed to the regular lenses we typically use on our cameras for stills. The electronic irises on these cameras are programmed for speed, not smoothness.

[Trevor Dennis]

Sorry, what is ASC?

[Chris Medico]

American Society of Camera dudes (cinematographers)

[Trevor Dennis]

I am trying hard to get to grips with shooting video with a DSLR, but finding it a steep learning curve compared with stills. Do I understand it correctly that DSLR footage is AVCHD, and that it is desirable to convert this to something like Cineform's Neoscene before editing? Or is that overkill for home videos? It's just that I now have a tracking shot that moved five feet in 70 seconds, (shot at 70mm on an APS/H camera) and while I am sure the tracking speed was smooth, it appears to suddenly accelerate momentarily when viewed in Premiere Pro CS5. It's the same when speeding up the footage two times, and is possibly a reduced version of the same jerky movement I spoke about at the start of this thread.