DV versus DVCAM Transitions

Robert Bunker · May 21st, 2008, 12:04 PM

On P. 19 of the PD-170 Operating Instructions in the "Notes" section under the heading "Usable Cassettes," it says, "If you record in the DV format, the transition of a tape may not be smooth. We recommend that you use mini DVCAM cassettes and set REC MODE to DVCAM in the menu settings to obtain reliable clear pictures."

Is this really an issue or just an effort to sell the DVCAM format and the cassettes it uses?

John Miller · May 21st, 2008, 12:29 PM

Quote:

Originally Posted by Robert Bunker

On P. 19 of the PD-170 Operating Instructions in the "Notes" section under the heading "Usable Cassettes," it says, "If you record in the DV format, the transition of a tape may not be smooth. We recommend that you use mini DVCAM cassettes and set REC MODE to DVCAM in the menu settings to obtain reliable clear pictures."

Is this really an issue or just an effort to sell the DVCAM format and the cassettes it uses?

I think it refers to insert editing and similar operations associated with accurately cueing the head at a previously recorded part of the tape rather than anything to do with overall picture quality. I've recorded about equal amounts of DVCAM and DV and haven't noticed any difference.

Re tapes, high grade MiniDV tapes are perfectly okay for DVCAM.

Mike Rehmus · May 21st, 2008, 12:39 PM

DVCam was designed for the broadcast world back when they didn't use non-linear editing systems, they used linear editing systems with their constant back and forth tape motion. Hence they needed rugged tape and cassettes because the broadcast folks heavily reuse their tape. If you drop a DVCam cassette, it is more likely to survive the abuse than if you drop a DV cassette.

The signal recorded in DV and DVCam is identical. The only difference is the DVCam 1's and 0's each are written to a wider magnetic spot in the tape because the tape is moving faster in DVCam.

At NAB, I got a Sony tech rep to agree that there is no quality difference between the two tape formats. And it really isn't a format difference, just the physical space taken by each 1 & 0.

For normal, single-pass use, the cheapest Sony tape is more than good enough. I've bought thousands of them from distributors and never had a bad tape or a tape-related recording failure.

Chris Medico · May 21st, 2008, 12:40 PM

The only difference between DV and DVCam is tape speed. DVCam runs at twice the speed of DV. Data rate and compression is the same.

DVCam with the higher tape speed has a higher signal to noise ratio. This helps prevent dropouts. Good tape is so good these days that dropouts don't happen often.

I would run DV mode using good tapes and not worry about running DVCam.

J. Stephen McDonald · May 21st, 2008, 09:38 PM

As I understand it, the DVCAM magnetic tracks are the same width as those of DV, but have a wider buffer area between them. Also, since the tape is moving faster, the helical tracks would have more curve to them and their required length would fit on a narrower width of the tape, leaving more free area along the margins. Note: DVCAM rolls the tape 50% faster than SP-mode DV.

Boyd Ostroff · May 24th, 2008, 03:42 PM

Getting back to Robert's original question.... I always thought that this warning in the manual referred to mixing both DV and DVCAM recordings on the same tape. In other words, if you do that you will get a bit of a glitch in the transition between a DVCAM and DV recorded section of the tape.

I love Sony products, but their manuals are just awful...

May 21st, 2008, 12:04 PM	#1
Robert Bunker New Boot Join Date: Mar 2008 Location: St Paul, MN Posts: 11	DV versus DVCAM Transitions On P. 19 of the PD-170 Operating Instructions in the "Notes" section under the heading "Usable Cassettes," it says, "If you record in the DV format, the transition of a tape may not be smooth. We recommend that you use mini DVCAM cassettes and set REC MODE to DVCAM in the menu settings to obtain reliable clear pictures." Is this really an issue or just an effort to sell the DVCAM format and the cassettes it uses?

May 21st, 2008, 12:39 PM	#3
Mike Rehmus Wrangler Join Date: May 2002 Location: Vallejo, California Posts: 4,036	DVCam was designed for the broadcast world back when they didn't use non-linear editing systems, they used linear editing systems with their constant back and forth tape motion. Hence they needed rugged tape and cassettes because the broadcast folks heavily reuse their tape. If you drop a DVCam cassette, it is more likely to survive the abuse than if you drop a DV cassette. The signal recorded in DV and DVCam is identical. The only difference is the DVCam 1's and 0's each are written to a wider magnetic spot in the tape because the tape is moving faster in DVCam. At NAB, I got a Sony tech rep to agree that there is no quality difference between the two tape formats. And it really isn't a format difference, just the physical space taken by each 1 & 0. For normal, single-pass use, the cheapest Sony tape is more than good enough. I've bought thousands of them from distributors and never had a bad tape or a tape-related recording failure. __________________ Mike Rehmus Hey, I can see the carrot at the end of the tunnel!

May 21st, 2008, 12:40 PM	#4
Chris Medico Major Player Join Date: Aug 2006 Location: NC, USA Posts: 356	The only difference between DV and DVCam is tape speed. DVCam runs at twice the speed of DV. Data rate and compression is the same. DVCam with the higher tape speed has a higher signal to noise ratio. This helps prevent dropouts. Good tape is so good these days that dropouts don't happen often. I would run DV mode using good tapes and not worry about running DVCam. __________________ Sony HVR-V1U (Arrived 12-21-06) Sony HDR-HC3 Sony DCR-VX1000 Sony CCD-VX3 (retired) HP Desktop w/ AMD 4200 & ATI 1600PRO Avid Liquid Pro 7.1 HP Laptop (field logging and rough editing) Pinnacle Studio 10 (semi-retired) Videos - http://dieseladdict.blip.tv

May 21st, 2008, 09:38 PM	#5
J. Stephen McDonald Major Player Join Date: Oct 2004 Location: Eugene, Oregon Posts: 717	As I understand it, the DVCAM magnetic tracks are the same width as those of DV, but have a wider buffer area between them. Also, since the tape is moving faster, the helical tracks would have more curve to them and their required length would fit on a narrower width of the tape, leaving more free area along the margins. Note: DVCAM rolls the tape 50% faster than SP-mode DV. __________________ Steve McDonald http://www.flickr.com/photos/22121562@N00/ http://www.vimeo.com/user458315/videos

May 24th, 2008, 03:42 PM	#6
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 10,925	Getting back to Robert's original question.... I always thought that this warning in the manual referred to mixing both DV and DVCAM recordings on the same tape. In other words, if you do that you will get a bit of a glitch in the transition between a DVCAM and DV recorded section of the tape. I love Sony products, but their manuals are just awful... __________________ http://tech.operaphilly.com \| The best in the business: DVinfo.net sponsors

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