View Full Version : 24p and Motion Smoothing


Richard Osuna
September 8th, 2006, 04:38 PM
Hi Guys -

I am shooting a short film on Saturday in 24P and after the tests that witnessed a lot of strobing, I plan on turning on the motion smoothing feature, as recommended in the JVC Handbook.

Any suggestions on shooting in 24P with the Motion Smoothing feature?

We have movement and dolly shots planned.

Thanks.

Tim Dashwood
September 8th, 2006, 05:07 PM
You better test it before you choose to use it. You won't see the effect of motion smooth until you play the tape back.

Personally, I avoid using it because it essentially creates "double-exposures" on each frame. The CCDs capture 48fps, every two frames are cross-dissolved and combined into a single frame before being written to tape at 24fps.

Richard Osuna
September 8th, 2006, 05:16 PM
Okay...but how do I prevent the jitter/strobing that takes place in 24P. I was following the handbook and it says to turn it on.

If I didn't use it, what settings should use to cause a film-like look at 24P with little to no strobing.

Thank you.

Chris Barcellos
September 8th, 2006, 05:40 PM
Maybe a slower shutter speed to create a blur with the motion ?

This is not my camera, but I am curious what will be said about resolving the issue you have.

But part of the problem may be resolved by slow pans and dolly shots.

Why do you have to shoot 24p. Going film out ?

Richard Osuna
September 8th, 2006, 05:59 PM
We wanted the film-look to it. Should we shoot in 30p and then covert to 24P using magic bullet?

Stephen L. Noe
September 8th, 2006, 06:02 PM
We wanted the film-look to it. Should we shoot in 30p and then covert to 24P using magic bullet?
What do you mean by "the film look" to you mean the film frame rate or do you mean the lattitude?

Are you literally doing a film transfer?

Richard Osuna
September 8th, 2006, 06:05 PM
I'd suppose it'd be for the look and softness of 24P.

Stephen L. Noe
September 8th, 2006, 06:15 PM
I'd suppose it'd be for the look and softness of 24P.
Are you going to be producing a DVD? a film transfer? Web delivery?

Richard Osuna
September 8th, 2006, 06:16 PM
Web delivery only.

Stephen L. Noe
September 8th, 2006, 06:22 PM
If it's web delivery only then I'd use 24p. There is no barrier to a 24p WMV, Flash or H.264 workflow (depending on NLE).

If it's to DVD, I'd choose the simpler 30p workflow.

Richard Osuna
September 8th, 2006, 06:48 PM
We're definitely going to use 24p...but what about the strobing....

should we turn on the motion smoothing as the JVC handbook suggests or should we shoot without it and just use plain 24p with 1/48th shutter speed?

Thank you.

Stephen L. Noe
September 8th, 2006, 07:29 PM
We're definitely going to use 24p...but what about the strobing....

should we turn on the motion smoothing as the JVC handbook suggests or should we shoot without it and just use plain 24p with 1/48th shutter speed?

Thank you.
Have you ever shot with a Bolex? You should shoot with 24 1/48 shutter w/o motion smoothing. This setting would be the same as shooting with a film camera. I'd think it would be more of a concern about the color gamut. Magic Bullet has some really great post filters. FilmFX also has stellar film stock post filters. Are you judging strobe by what you see on the LCD? or by the 24fps encoded WMV?

Richard Osuna
September 8th, 2006, 08:02 PM
The strobe was in the 24fps AVI... and I viewed it on an LCD.

This is going to be shot for the Net so I suppose I have to keep LCDs in mind.

Richard Osuna
September 8th, 2006, 08:14 PM
Adding to my last comment, which you gave me an idea...I rendered it out as ITVC (or something like that) at 23.96 fps and the strobing was greatly reduced on an LCD. It looked pretty good w/out the motion smoothing at 24p.

Stephan Ahonen
September 8th, 2006, 10:54 PM
WIth 24p you can't just throw motion around the frame like you can with video, you have to treat it very carefully because of the extremely low temporal resolution. I suspect that's the cause of your strobing.

Daniel Patton
September 9th, 2006, 12:12 AM
Richard, have you tested a segment rendered out to the size (reduced I hope) that you intend to deliver over the web? More than 90% of the content we produce is for web delivery and when edited, reduced and output to the format of final choice, it tends to look a bit less stroby than looking at the raw captured files (or even in your NLE for that matter).

Also, your audience is aware that they are viewing video delivered over the web, so expectations on "quality of playback" is far more forgiving than when they view that same content via traditional broadcast TV, DVD, etc.. You will have far more compression, file size/compatibility tradeoffs to scrutinize before all is said and done. That's not an excuse to forgo trying to achieve the best results from the start, but it's still something to consider when the end result is web only.

This may have been covered before with an answer to boot (it must have been) but does not the 60Hz of an LCD monitor lend better to the viewing of 30/60P frame rate content over a 24/48? Might this (even in part) be some of the issue with every ones constant concern and asking about strobbing content at 24P when working at the system level? I noticed that this topic gets brought up a lot around here.

I won't even pretend to know anything about that subject. But the great thing about this place is someone around here sure as hell does!! ;)