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-   -   XM2 frame mode jerky ? (https://www.dvinfo.net/forum/canon-gl-series-dv-camcorders/9856-xm2-frame-mode-jerky.html)

Scott Poolen May 20th, 2003 10:09 AM

XM2 frame mode jerky ?
Last week I bought an XM2 and today I've been experimenting with frame movie mode. But I notice a slight jerkiness. It's jerky in the footage itself but also on the viewfinder and lcd when filming. Is this normal?

Tustin Larson May 20th, 2003 12:44 PM

In a word... Yes

Richard Lin May 20th, 2003 08:49 PM

my gl2 also has a jerkiness, will this always occur or is there a way to stop it or get around it?

Chris Hurd May 20th, 2003 09:05 PM

The way to stop it or get around it is to switch the camera from Frame Movie mode back to Normal Movie mode. The way to work with it is to keep the camera very still, on a tripod if possible, and make only very slow and very careful pans, tilts and zooms. Hope this helps,

Richard Lin May 20th, 2003 10:05 PM

so then frame movie mode is somewhat useless...so to speak...do to the lack of mobility of the camera....i havent been able to really try it out cuz i been really really sick, but would it be shaky if i was moving quickly or trailing someone at a fast pace, like speed walking, while using a steadicam or dolly?

Joe Sacher May 21st, 2003 10:10 AM

Saying Frame Movie mode useless is just like saying shooting film at 24 fps is useless. Both work fine, but you must work within the limitation of format. If you try to film a picket fence in motion with a 24 fps film camera, you will get very annoying results. 60 fields per second just appears smoother. This doesn't make one mode more or less useful, it just defines the constraints that you must work under to create a video as you want.

One thing is certain, if you want to have any type of video whose final destination is a computer for display, the final format will be progressive. If you get to progressive via an interlaced format, the picture might be smoother. This is because it can't be as sharp when the de-interlacing blends fields. If you shoot progressive, you are going to still be sharp. However, you must make sure that you are careful in movements while shooting.

If you are trailing someone wall walking fast and the camera movement is fixed or slow in relative to the person being followed, you will get good results. The background might jump with the progressive frame change, but that usually doesn't matter because the focus (attention, not camera focus) is on the person.

Chris Hurd May 21st, 2003 10:18 AM

Excellent response, Joe... I'm really looking forward to your involvement here at DVinfo. Many thanks,

Richard Lin May 21st, 2003 04:57 PM

very impressive response, i retract my previous statement..hehe..
and thanks for answering my question.

Scott Poolen May 23rd, 2003 06:18 AM

Well, I'm of course a novice but it seems to me that Joe is claiming that filming fast action or doing fast camera movements in 24fps regardless of the medium (film, video) will result in jerky movements of the picture.
But I never see jerkiness in (hollywood) action movies, even though they are shot in 24p. I'm sure there is an easy explanation but I don't know it.

Hilary Cam May 23rd, 2003 08:37 AM


I notice the 'jerkiness' of 24fps in most Hollywood action films.

It was blatently obvious a few nights go in the Matrix Reloaded action scenes (ps I don't recommend this film, the first Matrix is superior). But as Joe alluded to, you don't tend to notice it if its movement is kept steady and focus/attention is on keeping the main figure stable in the shot.

It is especially noticeable in cinema projections; look for it next time you go. It is not as bad when viewed on TV due to high refresh rates and instantaneous electronic frame change - not the mechanised frame change in film projection (why did you think film projections are called 'FLICKS').

If you shoot in higher shutter speeds you will 'worsen' this flick effect, while if you shoot in lower shutter speeds (ie 1/50 or 1/25) the 'flick' will be visually reduced in playback, as each frame will be slightly blurred/smeered.

If you shoot in Frame Mode and 1/25 shutter speed on the XM2 you will infact capture every movement in time, reducing flick effect, but that movement - depending on the amount of motion - will result in smeering on each individual frame.

- I'm very tired, I hope this made coherent sense.

Joe Sacher May 23rd, 2003 09:09 AM

Another place where it is very easy to see the individual frames would be Yoda's Light Saber battle at the end of Star Wars II. They blured the saber such that it looked like a slice of pie, but you still see jumps in the path, because it moves so fast.

It should also be noted that some people can view flicker or reconize images faster than others. That makes this more of an annoyance to some than others. During some testing in WWII, some pilots were able to identify planes that were shown to them for only 1/100th of a second. Others took much longer.

Hilary Cam May 23rd, 2003 10:19 PM

Just being fair about giving credit here, rather then labeling these as 'Hollywood' productions, both the Matrix and Star Wars ep II were shot in Sydney by Sydney production houses, in fact much of the Matrix series was shot within a few kilometers from me, and I'm on the other side of the world of Hollywood.

Though this is hardly something for fellow aussies to gloat over as neither are much of an achievement, as they both stunk, in my opinion ;)

Peter Jefferson May 23rd, 2003 10:56 PM

"But I never see jerkiness in (hollywood) action movies, even though they are shot in 24p. I'm sure there is an easy explanation but I don't know it."

Some action sequences are shot in a variable frame rate.. some even going as high as 120fps with extreme shutter speeds.. the footage is then run at normal speed (24fps) which decreases the speed of the footage(giving that slomo), then is sped up again in post and the "in between" frames are pretty much used as an interlacing tool virtually eliminating any artifacts.
Now this is how ive seen it done, but im sure that there are many other ways to do it...

as for the jerkiness, a slower shutter(as mentioned) usually helps, on top of that the stills which are extracted are a little cleaner.

I dont use canons, but i do know that Panas have a great frame mode (even the MX500 gives an awsome film like effect when u decrease the lense sharpness and colour saturation)
So that kind of setting might be a way around your conundrum..

On top of that, i can usually film medium to high speed shots using frame and it comes out fine.. But that could be the camera itself.
Obviosuly different cams process in different ways, the LCD will be jerky or "strobing" (even the DVX100 and XL1s jerk a bit) but thats due to slow refresh of LCD...

Best way is to experiment.. even filming moving traffic would be a good way to learn how to set it up for different purposes.

good luck

Ken Tanaka May 23rd, 2003 11:59 PM

One note worth adding to these remarks is to make sure that you are also mindful of the status of your camera's image stabilizer. For mounted shots or shots where you anticipate fast camera motion it's best to turn it off. Leaving it on can also lead to a certain jerkiness as the lens attempts to compensate for what it "identifies" as anomalous motion.

Rob Lohman May 26th, 2003 05:24 AM

Also some of the jerkyness can be removed by playing around
with the shutter settings. Give it a try and see what happens.

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