Full 1280x720 or not!? at DVinfo.net

Ken Hodson · October 29th, 2003, 09:14 PM

I keep reading bits and bites about how this camera is not capturing true 720p. I have searched for past threads to find out what the facts are but have come up blank.
Could someone post a link to a past thread where this is clarified, or explain it here.
Thanx
Ken

Stephen L. Minor · October 30th, 2003, 02:35 AM

Ken,

Please describe, why is it not true?

Maybe they mean the (temporal rez) 30p frame rate instead of 60p. Yea, it's not really a HD standard (unless it's brand new since the cam came out), thats why the cam has the option to convert up/down when viewing w/ cables. Component or Composite whatever, I always confuse the two.

Christopher Toderman · October 30th, 2003, 03:32 AM

The resolution lies somewhere near the midpoint between 480p and 720p. Steve Mullen had an article in Video Systems and he described there why the horizontal resolution is, what I remember, about 25% lower. The chip also does not produce full vertical resolution. 720p Varicam has full resolution, plus true high quality HD lenses that do not degrade this resolution, or picture. In addition to that the transfer rate on this camera is mere 19 Mbps. From what I have seen, and what Steven Mullen mentioned, even the #900 Panasonic, 4:2:2 color, 50 Mbps, has a significantly better picture. I personally liked better also the DVX, 25 Mbps, picture in progressive. These comparisons were made after material of all 3 cameras was transfered to 1080i, standard HD broadcast speed. I can't believe that some people here stated that the picture on this camera is anywhere close to CineAlta quality or that it is better than #900 Panasonic, which uses real pro lenses. Let's get real here.

Eric Bilodeau · October 30th, 2003, 06:32 AM

The chip is not 25% less than true 720p. True 720p is equal to 921600 pixels (1280X720), the active pixel zone of the CCD is 840000, or 0,91:1, not much lower. Remember that we are in HD and a lower (78000 pixel lower) count is not as bad as in the case of SD, for example the XL1s has a 250000 active pixels set of CCDs, lower than the resolution of SD witch is 345600 pixels (720X480), a mere 0,72:1 pixel ratio, much worse because of the lower definition, still it does a very good image (not as sharp as a 420000 pixels set of CCDs of course).

You worry on very subtle details. if you can tell the resolution difference between the HD10 and a 1:1 aspect HD 720 like the varicam, you have much better eyes than me (and the rest of the team whom I worked with), we tested both cameras head to head and resolution is absolutely equivalent.

Steve Mullen · October 30th, 2003, 08:11 AM

Resolution is deterrmined by visual line count -- not pixel count.

I used the measured -- Japan -- numbers for the camcorder.

But this is true of all camcorders -- only I haven't seen measurements on a CineAlta.

But the fact is that it looks like HDCAM rez because very few monitors can reproduce more than JVC rez.

I really don't see much point to the debate.

Alex Raskin · October 30th, 2003, 08:57 AM

<<<-- Originally posted by S. L. Minor : Maybe they mean the (temporal rez) 30p frame rate instead of 60p. Yea, it's not really a HD standard -->>>

"SMPTE 296M: 1280 × 720 Scanning, Analog and Digital Representation and Analog Interface
This standard defines a family of raster scanning systems for the representation of stationary or moving two-dimensional images sampled temporally at a constant frame rate and having an image format of 1280 × 720 and an aspect ratio of 16:9."
Source: http://www.atsc.org/document_map/interfaces.htm#1280%20×%20720

So it is ATSC standard.

Steve Mullen · October 30th, 2003, 12:36 PM

Alex, rez is NOT measured by CCD specs or the format specs.

NTSC, for example, has 480-lines and CCDs have 480-rows. Measured rez can NOT be greater than 360-lines.

Alex Raskin · October 30th, 2003, 01:00 PM

Actually I commented only on whether or not 1280x720 is in fact a HD standard.

My post quoted the ATSC to confirm that the answer is positive.

Ken Hodson · October 30th, 2003, 01:41 PM

Thanks for the clarification guys. It's what I thought, not a big deal. Flame related posts seem to always bring it up, "even Steve Mullen says so!"
Ken

October 30th, 2003, 02:35 AM	#2
Stephen L. Minor Regular Crew Join Date: Sep 2003 Location: L.A., CA Posts: 35	Ken, Please describe, why is it not true? Maybe they mean the (temporal rez) 30p frame rate instead of 60p. Yea, it's not really a HD standard (unless it's brand new since the cam came out), thats why the cam has the option to convert up/down when viewing w/ cables. Component or Composite whatever, I always confuse the two. __________________ -S

October 30th, 2003, 06:32 AM	#4
Eric Bilodeau Major Player Join Date: Jun 2003 Location: Chicoutimi, Canada Posts: 334	The chip is not 25% less than true 720p. True 720p is equal to 921600 pixels (1280X720), the active pixel zone of the CCD is 840000, or 0,91:1, not much lower. Remember that we are in HD and a lower (78000 pixel lower) count is not as bad as in the case of SD, for example the XL1s has a 250000 active pixels set of CCDs, lower than the resolution of SD witch is 345600 pixels (720X480), a mere 0,72:1 pixel ratio, much worse because of the lower definition, still it does a very good image (not as sharp as a 420000 pixels set of CCDs of course). You worry on very subtle details. if you can tell the resolution difference between the HD10 and a 1:1 aspect HD 720 like the varicam, you have much better eyes than me (and the rest of the team whom I worked with), we tested both cameras head to head and resolution is absolutely equivalent. __________________ Eric Bilodeau video SFX,DOP ___________________ http://www.fictis.net info@fictis.net

October 30th, 2003, 08:11 AM	#5
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	Resolution is deterrmined by visual line count -- not pixel count. I used the measured -- Japan -- numbers for the camcorder. But this is true of all camcorders -- only I haven't seen measurements on a CineAlta. But the fact is that it looks like HDCAM rez because very few monitors can reproduce more than JVC rez. I really don't see much point to the debate. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

October 30th, 2003, 12:36 PM	#7
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	Alex, rez is NOT measured by CCD specs or the format specs. NTSC, for example, has 480-lines and CCDs have 480-rows. Measured rez can NOT be greater than 360-lines. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

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October 29th, 2003, 09:14 PM	#1
Ken Hodson Trustee Join Date: Aug 2003 Location: Vancouver BC Canada Posts: 1,315	Full 1280x720 or not!? I keep reading bits and bites about how this camera is not capturing true 720p. I have searched for past threads to find out what the facts are but have come up blank. Could someone post a link to a past thread where this is clarified, or explain it here. Thanx Ken __________________ Damnit Jim, I'm a film maker not a sysytems tech.

October 30th, 2003, 03:32 AM	#3
Christopher Toderman Regular Crew Join Date: Sep 2003 Location: New York Posts: 60	The resolution lies somewhere near the midpoint between 480p and 720p. Steve Mullen had an article in Video Systems and he described there why the horizontal resolution is, what I remember, about 25% lower. The chip also does not produce full vertical resolution. 720p Varicam has full resolution, plus true high quality HD lenses that do not degrade this resolution, or picture. In addition to that the transfer rate on this camera is mere 19 Mbps. From what I have seen, and what Steven Mullen mentioned, even the #900 Panasonic, 4:2:2 color, 50 Mbps, has a significantly better picture. I personally liked better also the DVX, 25 Mbps, picture in progressive. These comparisons were made after material of all 3 cameras was transfered to 1080i, standard HD broadcast speed. I can't believe that some people here stated that the picture on this camera is anywhere close to CineAlta quality or that it is better than #900 Panasonic, which uses real pro lenses. Let's get real here.

October 30th, 2003, 08:57 AM	#6
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	<<<-- Originally posted by S. L. Minor : Maybe they mean the (temporal rez) 30p frame rate instead of 60p. Yea, it's not really a HD standard -->>> "SMPTE 296M: 1280 × 720 Scanning, Analog and Digital Representation and Analog Interface This standard defines a family of raster scanning systems for the representation of stationary or moving two-dimensional images sampled temporally at a constant frame rate and having an image format of 1280 × 720 and an aspect ratio of 16:9." Source: http://www.atsc.org/document_map/interfaces.htm#1280%20×%20720 So it is ATSC standard.

October 30th, 2003, 01:00 PM	#8
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	Actually I commented only on whether or not 1280x720 is in fact a HD standard. My post quoted the ATSC to confirm that the answer is positive.

October 30th, 2003, 01:41 PM	#9
Ken Hodson Trustee Join Date: Aug 2003 Location: Vancouver BC Canada Posts: 1,315	Thanks for the clarification guys. It's what I thought, not a big deal. Flame related posts seem to always bring it up, "even Steve Mullen says so!" Ken __________________ Damnit Jim, I'm a film maker not a sysytems tech.