Fast Motion Pixelation at DVinfo.net

Brad Schreiber · July 4th, 2006, 02:16 AM

I've noticed I get tape pixelations whenever the Camera Whips or Pans quickly. Sometimes the move is not highly exxagerated, yet the pixelations happen anyway. Any thoughts on why this happens, or could it be a digitizing (into my NLE) problem? I don;t have a full rez HD monitor to watch my footage on, so I cannot eliminate on possibility or the other.

Vincent Rozenberg · July 4th, 2006, 03:31 AM

Never noticed it on my cam, but maybe you found out the limitations of the HDV format.

Yasser Kassana · July 4th, 2006, 07:18 AM

Your using cineform right? WIth what NLE?? Once we have that info we might be able to help.

Chris Hurd · July 4th, 2006, 08:17 AM

Whip pans are an HDV torture test. The format is not designed to hold up to that sort of abuse!

Brad Schreiber · July 4th, 2006, 09:47 AM

My workflow is Cineform into m2t's-MPEG Streamclip into Quicktimes-Import into AXP 5.5. I work off of Seagate eSATA 3.0Gb/s drives.

Harold Schreiber · July 4th, 2006, 10:35 AM

Hi Brad,

Sorry to go off subject, but do you have any relatives out of the Topeka, Kansas area ??

Harold Schreiber, Jr.

Barlow Elton · July 4th, 2006, 12:13 PM

You have to take it all in context. I think HDV breaks down more on intense, constant and random high frequency motion like a close up of rushing, frothing water(I've personally tested this comparing HDV and SDI on the same scene). But you have to freeze frame for it to be terribly noticeable. The F modes handle this kind of thing better than 1080i HDV (whip pans especially) because of progressive encoding, which is much more efficient with MPEG2, and actually 24F does the best because it gets the most bits per frame.

This is why SDI is important for acquisition. You can use it exclusively for scenes that might break the HDV codec. If you look to the SDI port for acquisition you can think of the camera as format agnostic.

We need a laptop SDI card or Firestore SDI (not holding my breath) and this sort of problem will be a thing of the past.

Alister Chapman · July 4th, 2006, 01:32 PM

Do you get the pixelation on the raw M2T's, Ive seen some software codecs introduce errors. Also be sure the tape heads are clean. Dirty heads will lead to increased use of error correction which will fall over during high data scenes. I've never seen pixelation on a clean M2T, only an increase in artifacts and blocking. I suggest you are getting an error introduced somewhere.

Brad Schreiber · July 4th, 2006, 03:14 PM

I just heard from a friend of mine who is a Post Supervisor. He has postulated the artifacting I see is caused by playback issues (coming from my PC), not issues with the image itself. I do not have an HD client monitor, so I will have to hope that this is the case.

Jon Bickford · July 5th, 2006, 03:43 AM

I had several whip pans in a recent shoot @30F and i have to say that my eye was not able to catch the HDV at work at all during playback, I was very impressed, there's so many "no-no's" associated with HDV that i'm always a little nervous to push the camera but pretty much every time i do i'm happy with the results... a BIG step from sony.

July 4th, 2006, 02:16 AM	#1
Brad Schreiber Regular Crew Join Date: Feb 2006 Location: Los Angeles, CA Posts: 96	Fast Motion Pixelation I've noticed I get tape pixelations whenever the Camera Whips or Pans quickly. Sometimes the move is not highly exxagerated, yet the pixelations happen anyway. Any thoughts on why this happens, or could it be a digitizing (into my NLE) problem? I don;t have a full rez HD monitor to watch my footage on, so I cannot eliminate on possibility or the other.

July 4th, 2006, 08:17 AM	#4
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Whip pans are an HDV torture test. The format is not designed to hold up to that sort of abuse! __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 4th, 2006, 09:47 AM	#5
Brad Schreiber Regular Crew Join Date: Feb 2006 Location: Los Angeles, CA Posts: 96	MPEG Streamclip into Quicktimes into AXP 5.5 My workflow is Cineform into m2t's-MPEG Streamclip into Quicktimes-Import into AXP 5.5. I work off of Seagate eSATA 3.0Gb/s drives.

July 4th, 2006, 10:35 AM	#6
Harold Schreiber Major Player Join Date: Jul 2006 Location: Olathe, Kansas Posts: 309	Off Subject Hi Brad, Sorry to go off subject, but do you have any relatives out of the Topeka, Kansas area ?? Harold Schreiber, Jr.

July 4th, 2006, 01:32 PM	#8
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Do you get the pixelation on the raw M2T's, Ive seen some software codecs introduce errors. Also be sure the tape heads are clean. Dirty heads will lead to increased use of error correction which will fall over during high data scenes. I've never seen pixelation on a clean M2T, only an increase in artifacts and blocking. I suggest you are getting an error introduced somewhere. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

July 4th, 2006, 03:31 AM	#2
Vincent Rozenberg Major Player Join Date: Jan 2006 Location: Rotterdam, The Netherlands Posts: 475	Never noticed it on my cam, but maybe you found out the limitations of the HDV format.

July 4th, 2006, 07:18 AM	#3
Yasser Kassana Major Player Join Date: Oct 2005 Location: UK Posts: 223	Your using cineform right? WIth what NLE?? Once we have that info we might be able to help.

July 4th, 2006, 12:13 PM	#7
Barlow Elton Major Player Join Date: Mar 2005 Location: UT Posts: 945	You have to take it all in context. I think HDV breaks down more on intense, constant and random high frequency motion like a close up of rushing, frothing water(I've personally tested this comparing HDV and SDI on the same scene). But you have to freeze frame for it to be terribly noticeable. The F modes handle this kind of thing better than 1080i HDV (whip pans especially) because of progressive encoding, which is much more efficient with MPEG2, and actually 24F does the best because it gets the most bits per frame. This is why SDI is important for acquisition. You can use it exclusively for scenes that might break the HDV codec. If you look to the SDI port for acquisition you can think of the camera as format agnostic. We need a laptop SDI card or Firestore SDI (not holding my breath) and this sort of problem will be a thing of the past.

July 4th, 2006, 03:14 PM	#9
Brad Schreiber Regular Crew Join Date: Feb 2006 Location: Los Angeles, CA Posts: 96	Possible Cause I just heard from a friend of mine who is a Post Supervisor. He has postulated the artifacting I see is caused by playback issues (coming from my PC), not issues with the image itself. I do not have an HD client monitor, so I will have to hope that this is the case.

July 5th, 2006, 03:43 AM	#10
Jon Bickford Major Player Join Date: Nov 2004 Location: Las Vegas, NV., Los Angeles, CA, Posts: 220	I had several whip pans in a recent shoot @30F and i have to say that my eye was not able to catch the HDV at work at all during playback, I was very impressed, there's so many "no-no's" associated with HDV that i'm always a little nervous to push the camera but pretty much every time i do i'm happy with the results... a BIG step from sony. __________________ Jon Bickford, Trepany Films San Pedro, CA Trephine001@aol.com