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09-19-2015, 10:37 AM   #1
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Jerky video from K-3

I did a quick test. I stood in my living room flipped the switch to video and hit record. Then I turned 360 degrees slowly.

Then I watched it on VLC on my computer. One thing bothers big time. The normal stuff like focus and light can easily fixed, but this is terrible. The movement is jerky. When the whole scene is moving in jumps.

I made also an animal test and recorded my cat's tail. It moves smoothly on video too.

So is this feature from AVHDC or is this something else which could have some cure? SR?

This thing doesn't happen with old HDV camera which spits out MPEG2-ts through firewire.

09-19-2015, 10:45 AM   #2
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Does it look smooth on your camera playback? If so, it is fine, its just a problem with your computer. I have a mac mini from 2009, and when i playback video's i've edited, often the video is choppy.
Also try filming without SR, see if it helps. It shouldn't be because of the AVCHD.
09-19-2015, 12:40 PM   #3
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Hmm.

Definetly it isn't me. Pentax K-3 Review - Movie/Video Mode | PentaxForums.com Reviews when panning in lower video, I can see the jerkiness also. If it isn't there, then it is my computers.
09-19-2015, 12:54 PM   #4
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At least don't use the shake reduction. It is software based and degrades the quality of the material you are shooting. Instead shoot from a stable platform like a tripod.

Edit: And when you want to shoot from a tripod a good videohead for panning is helpful.

10-25-2015, 06:40 AM   #5
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The video card on your computer can't handle it.
10-25-2015, 12:24 PM   #6
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Also, try a different player on the PC. MediaPlayerClassic for example. Not all players are equal.
But yeh, if playback is smooth when reviewed on the camera but not on you PC, then it's your PC.
I don't think the K-3 uses AVHDC but h.264 codec.
10-27-2015, 08:06 PM   #7
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QuoteOriginally posted by anemone Quote
Hmm. Definetly it isn't me. Pentax K-3 Review - Movie/Video Mode | PentaxForums.com Reviews when panning in lower video, I can see the jerkiness also.
Note the jerkyness occurs more when panning to the left, then panning to the right?
That's because of the Rolling Shutter in the sensor, which scans pixel by pixel, line by line. I've gotten used to making sure action and fast movements in video lead to Left to Right panning, to avoid that as much as possible.
Your old HDV camera will have a small single CCD or 3CCD sensor block - CCD's were Global Shutters in the vast majority, and so their motion capture is better IMHO.
That applies for both Progressive Sensors, and Interlaced Sensors - the Interlaced ones presented all the odd lines in one field, and all the even lines in the next.

Rolling Shutter, motion artifacts, and signal noise, are the three main reasons it took much longer for TV Broadcasters to update to CMOS sensor based cameras, compared to the consumer market.
10-28-2015, 12:21 AM   #8
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QuoteOriginally posted by PiDicus Rex Quote
Note the jerkyness occurs more when panning to the left, then panning to the right?
That's because of the Rolling Shutter in the sensor, which scans pixel by pixel, line by line. I've gotten used to making sure action and fast movements in video lead to Left to Right panning, to avoid that as much as possible.
Your old HDV camera will have a small single CCD or 3CCD sensor block - CCD's were Global Shutters in the vast majority, and so their motion capture is better IMHO.
That applies for both Progressive Sensors, and Interlaced Sensors - the Interlaced ones presented all the odd lines in one field, and all the even lines in the next.
Thanks. That nailed it. Now that I understand what I'm seeing think it would be possible to design test equipment. CPU fan, microcontroller and speed display. When taking video of the fan, would be different on top compared to bottom.

After seeing those motion distortion effects I haven't been unable to see it. Sometimes I can see those in TV too.

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