View Full Version : AVCHD=Motion Blur?

2nd November 2011, 07:14 PM
Hi All,

These days I'm filming with GH2 & 2 more AVCHD consumer camcorders. I realized that no matter how strong or low light in the room, AVCHD cams giving me bad motion blur result. Just like a simple interview shot, cam on tripod with 1/50 Shutter Speed, it'll just easily appearing motion blur when the interviewer moved his hands, head or body! Yiep, it was pretty smooth & nice video when watch on it's (like GH2) own LCD but horrible motion blur while transcode & view in editing software (computer screen). Videos are showing motion blur on FullHD TV (view via cam's USB out) too.

Did you realized? What were you do on cam setting before you record video & what'll you do after transcoding in to editing software just like FCP?

Your opinion is really appreciate! Thanks! ;)

2nd November 2011, 07:29 PM
AVCHD has nothing to do with motion blur.
Do a bit of research on interlaced and progressive shooting!
Shoot in the method that you need for your playback.
Shoot interlaced for TV - this will look bad on computer as it is a progressive screen, but will look good on TV.
Or Shoot progressive for computer and web playback. You can also deinterlace footage for web playback when compressing for the web.
Cheers, Rob

3rd November 2011, 01:56 AM
Hi Rob,

Here you are to reply me again, appreciate! :D

1) I did shoot in 1080i vs 720p, and the motion blur was really obvious with 1080i and Smooth at all with 720p in the same setting like 1/50 shutter speed & auto focus. Because of PROGRESSIVE?

2) Something strange is when I set the editing timebase to 50fps for 1080i footage edit, playback just as smooth as the result shoot with 720p! Same footage as the above test! What do you say? This is something I don't understand. And yup, exported as 50 frame rate from this editing time base looks smooth motion (no motion blur at all).

3) Shoot in 1080i:
- When interview a man with a man standing & have some move in front of GH2 (cam on tripod) like raise his hands, swing his head & body...motion blur appears!
- When interview a man with sit on a office chair & have the same movement as above (cam on tripod), motion blur reduced & acceptable! What's the theory to explain this?
- More weird here. When shoot with handheld cam & move around the standing moving man, reduced motion blur (acceptable result)! Huh... How could this chemical effect be?

4) Exported to Progressive or De-interlaced can do nothing to the bad motion blur. But killed all Jerker Issue by interlaced.

So, isn't the bad of AVCHD? It's about i/p issue & TV vs Computer playback issue? So s'ld I go with a TV type monitor (i) while editing (playback on i device) for better preview?

3rd November 2011, 07:20 AM
Hi Mactreouser,
I'm not sure what you are doing with ---2). Shooting at 25fps and editing at 50fps?
Are you speeding up the footage?
With 3). How are you viewing the video -- on an interlaced TV, or computer?
I don't understand the bad motion blur problem. Must be a playback issue on a progressive monitor.
Yes, your last sentence is what I said it is all about. Shoot interlaced or progressive depending on what output monitor and method you require.
Cheers, Rob

3rd November 2011, 01:06 PM

Thanks again!

1) shoot 25fps & edit 50fps time base--it was just a test, strange, it works! But this is not really the theory as we know, but it just work! 2ndly, I did not speed it up, playback as normal speed!

2) yiep, I playback on computer while editing, did not use any tv as monitor. Maybe, that's why motion blur for computers are progressive screen? In fact, I playback on 1080 FullHD TV via USB from GH2, motion blur result is still the same!

3) how to manage the shoot if the footage use for DVD production & Web Promotion? Shoot in 1080i or 720p? In fact, 720p might loose a lot of pixels, don't you think so? Cause it'll be burn in to HD DVD.

Thanks for help no matter in theory or practically! ;)


3rd November 2011, 07:34 PM
3) Shoot at 1080i make the DVD, then de-interlace and compress a copy of the movie for the web.
Cheers, Rob

4th November 2011, 02:14 AM

1) 1080i for DVD. No de-interlace or progressive while compressing stage?
2) De-interlace for Web. What if Progressived the file while compressing stage (if compression software do have the option to Progressived?
3) if playback while editing on computer looks strong motion blur (quit disturbing), link up an external tv type as monitor (DVI or VGA out) will shown the better result?


4th November 2011, 06:18 AM
Make sure your sequence settings in FCP are the same - 25fps 1080i (interlaced).
Video out fro mfcp must be true video signal - via hdmi or firewire.

Cheers, Rob

4th November 2011, 08:29 AM

Thanks for confirmation!

1) sequence confirmed 25fps with 1080i

2) true video out means must be out via HDMI or RCA? VGA or DVI will not giving true video, am I right?

3) Are you a FCP user? I just wanna ensure the true video out setting. Just turn on the external monitor for preview?

Thanks & appreciate to your helps!

4th November 2011, 09:53 AM
Hi again,
Yes I'm a FCP user, I've worked in TV for 40years.
Outputting (interlaced or even Progressive), video to a Proper TV monitor while editing in FCP is the only way to really preview, see Fields and interlacing issues or colour grade.
Output must be through firewire connection or the new Blackmagic HDMI cards.

Cheers, Rob

4th November 2011, 04:36 PM

Wow..wow.. Is my pleasure to chat with an experienced senior! :D

Btw, it means DVI out to external TV might not able to judge anything?

And, no matter what region it is, DVD playback definitely playback in Progressive?

Then, what about TV itself? Nowadays, those LCD or LED work with 2 options (interlaced or progressive)? Or, it depends to the region?

Thanks again!

4th November 2011, 08:08 PM
Yes DVI out to a monitor is just a second computer monitor (not sure how you have it set up), not a true video signal.
You must output from the Matrox, Kona and Decklink devices for a true NTSC/PAL video signal!
A DVD player uses flags to convert progressive content into interlaced video for playback. So it will handle both, but outputs as interlaced.
It is up to you if you want to shoot in Progressive or Interlaced, but then edit and process in that method. Just do some googling to find out more. New TVs will work with both, but progressive will still look jumpy on fast action or pans.
Cheers, Rob

21st February 2013, 06:06 PM
Don't know about other programs but in Sony vegas I right click on the clip on the timeline and change smart resample to disable resample. Plays clean after that.