Canon XL2 image resolution vs DV format at DVinfo.net
DV Info Net

Go Back   DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon HDV and DV Camera Systems > Canon XL and GL Series DV Camcorders

Canon XL and GL Series DV Camcorders
Canon XL2 / XL1S / XL1 and GL2 / XM2 / GL1 / XM1.

Reply
 
Thread Tools Search this Thread
Old May 10th, 2008, 07:02 PM   #1
New Boot
 
Join Date: May 2008
Location: Swindon UK
Posts: 11
Canon XL2 image resolution vs DV format

Hi everyone!
I am not sure if I understand the image resolution of XL2. It says that XL2 has 960x576 effective pixels in 16x9 mode.
But as I know DV format cannot have higher res than 720x576.
Is there any possibility to record DV in 960x576 on normal DV tape? Or that higher sensor resolution is being scaled down to 720x576 giving just sharper image in normal DV mode?
Sorry for any spelling errors, I am not english :)
Krystian Dobak is offline   Reply With Quote
Old May 10th, 2008, 07:07 PM   #2
Obstreperous Rex
 
Join Date: Jan 2001
Location: San Marcos, TX
Posts: 27,366
Images: 513
See my article at http://www.dvinfo.net/canonxl2/articles/article06.php

It was written for NTSC but also applies to PAL (change 480 to 576).

The answer is that it scales to 960 for recording to tape.
__________________
CH

Search DV Info Net | 20 years of DVi | ...Tuesday is Soylent Green Day!
Chris Hurd is offline   Reply With Quote
Old May 11th, 2008, 07:59 AM   #3
Regular Crew
 
Join Date: Apr 2008
Location: Gaithersburg, MD
Posts: 51
So would shooting Direct-to-disk maintain the 960x576 effective pixels in 16:9?
And if so, wouldn't it make more sense to just bypass the tape completely?
Andrew Hoag is offline   Reply With Quote
Old May 11th, 2008, 08:21 AM   #4
Obstreperous Rex
 
Join Date: Jan 2001
Location: San Marcos, TX
Posts: 27,366
Images: 513
It might depend on which direct-to-disk solution, but generally speaking, the answer is no. Most all direct-to-disk options are specifically DV format, so the recorded width will never exceed 720 pixels.

If you are looking for a higher-resolution recording, consider an HD format such as HDV. The Canon XH A1 records native 16:9 (which is 1440 anamorphic x 1080) in HDV and costs about the same as the Canon XL2.
__________________
CH

Search DV Info Net | 20 years of DVi | ...Tuesday is Soylent Green Day!
Chris Hurd is offline   Reply With Quote
Old May 11th, 2008, 11:27 AM   #5
Regular Crew
 
Join Date: Apr 2008
Location: Gaithersburg, MD
Posts: 51
Well I am already shooting everything on the XL2, but I'm also running the Adobe Production Suite, which includes OnLocation. I've also been considering the FireStore, is any of this going to get me a higher res?
Andrew Hoag is offline   Reply With Quote
Old May 12th, 2008, 02:36 AM   #6
Major Player
 
Join Date: Jan 2008
Location: Norwegian lost in California
Posts: 890
Quote:
Originally Posted by Andrew Hoag View Post
So would shooting Direct-to-disk maintain the 960x576 effective pixels in 16:9? And if so, wouldn't it make more sense to just bypass the tape completely?
Quote:
Originally Posted by Chris Hurd View Post
It might depend on which direct-to-disk solution, but generally speaking, the answer is no.
So is there any direct-to-disk system that handles 960x576 pixels in 16:9?

-- peer
__________________
www.NoPEER.com
Peer Landa is offline   Reply With Quote
Old May 12th, 2008, 08:27 AM   #7
Obstreperous Rex
 
Join Date: Jan 2001
Location: San Marcos, TX
Posts: 27,366
Images: 513
To my knowledge, all direct-to-disk or direct-to-edit options that I'm aware of are format-specific, meaning they will record DV at 720x480 (or 720x576) and / or HDV or DVCPRO HD at 1280 x 720 or 1440 x 1080.
__________________
CH

Search DV Info Net | 20 years of DVi | ...Tuesday is Soylent Green Day!
Chris Hurd is offline   Reply With Quote
Old May 12th, 2008, 05:27 PM   #8
Regular Crew
 
Join Date: Apr 2008
Location: Gaithersburg, MD
Posts: 51
Quote:
Originally Posted by Chris Hurd View Post
To my knowledge, all direct-to-disk or direct-to-edit options that I'm aware of are format-specific, meaning they will record DV at 720x480 (or 720x576) and / or HDV or DVCPRO HD at 1280 x 720 or 1440 x 1080.

It just seems senseless for the XL2 to even have the 950 by 576 pixel ratio if it's going to be scaled down to 750.

Someone needs to get a DTD solution for it. Any programmers or engineers around?
Andrew Hoag is offline   Reply With Quote
Old May 12th, 2008, 09:56 PM   #9
Major Player
 
Join Date: Dec 2003
Location: Newberg, Oregon
Posts: 494
I don't have any links, but I know there are people who will "MOD" your XL2 with a jack that puts out uncompressed video. It basically involves opening up the camera and hardwiring in some jacks that take the image from the CCDs before it gets downconverted to DV.

That's about the extent of my information, but I'm sure you can find stuff by googling. If I recall, the people who do it charge a good amount of money, and with the cost of the XL2 + that money, you could buy an HDV camera.
Jeremiah Rickert is offline   Reply With Quote
Old May 14th, 2008, 10:52 AM   #10
New Boot
 
Join Date: Sep 2007
Location: Ventura, CA
Posts: 15
Yeah, but not uncompressed HD. I'd take uncompressed SD over compressed HDV any day.
David Del Real is offline   Reply With Quote
Old May 14th, 2008, 01:39 PM   #11
Major Player
 
Join Date: Oct 2005
Location: Hillsborough, NC, USA
Posts: 968
Quote:
Originally Posted by Krystian Dobak View Post
Hi everyone!
I am not sure if I understand the image resolution of XL2. It says that XL2 has 960x576 effective pixels in 16x9 mode.
But as I know DV format cannot have higher res than 720x576.
Is there any possibility to record DV in 960x576 on normal DV tape? Or that higher sensor resolution is being scaled down to 720x576 giving just sharper image in normal DV mode?
Sorry for any spelling errors, I am not english :)
"effective" is the key word. The sensors are 16:9 but each horizontal line is sampled at the D1 rate which gives 720 samples per line in the video image. i.e., even though the sensors have >950 pixels horizontal, the signal fed into the compression electronics on the camcorder doesn't have that resolution.

DV only permits two frame sizes: 720 x 480 (NTSC) and 720 x 576 (PAL).

The DV signal carries a marker that tells display equipment whether the video is 4:3, 16:9 or one of a number of other options (2.35:1, 14:9 etc). On a 16:9 display, the image will be stretched and will end up looking like it has a resolution of ~960 x 576. But it isn't that resolution. The resolution is still 720 x 576 - it's just that the pixels are stretched.

As mentioned elsewhere, to get the full uncompressed, native image you have to get to the sensor signals before they are digitized/corrected etc etc.
John Miller is offline   Reply With Quote
Old May 15th, 2008, 06:48 AM   #12
Major Player
 
Join Date: Jan 2008
Location: Norwegian lost in California
Posts: 890
Quote:
Originally Posted by Jeremiah Rickert View Post
I don't have any links, but I know there are people who will "MOD" your XL2 with a jack that puts out uncompressed video. It basically involves opening up the camera and hardwiring in some jacks that take the image from the CCDs before it gets downconverted to DV.
I had no luck finding this on Google. Hence, any pointers appreciated.

-- peer
__________________
www.NoPEER.com
Peer Landa is offline   Reply With Quote
Old May 15th, 2008, 09:05 AM   #13
Major Player
 
Join Date: Apr 2004
Location: Ann Arbor, MI
Posts: 342
You may be thinking about Andromeda from Reel Stream. The owner - Juan something - sold it to an unknown buyer, with much conjecture that it was the Red/Scarlet team. There is also unconfirmed news (from a usually reliable source) that he is now working at Panasonic corporate in Japan.

The web site is still up, but you really have to dig to find that they are not actually selling any longer, though DVX's with this mod are being bought and sold like "Penny Blacks".

2-3 years ago (pre-NAB) when I first discovered Andromeda, $2,500 for 4:4:4 out of a DVX, and recording it direct to your laptop, did not seem so outrageous.

http://www.reel-stream.com/andromeda.php
Jack Barker is offline   Reply With Quote
Old May 15th, 2008, 09:34 AM   #14
Obstreperous Rex
 
Join Date: Jan 2001
Location: San Marcos, TX
Posts: 27,366
Images: 513
Quote:
Originally Posted by Andrew Hoag View Post
It just seems senseless for the XL2 to even have the 950 by 576 pixel ratio if it's going to be scaled down to 750.
You mean 960 scaled down to 720. But you have to realize that if it isn't scaled down to 720, then it's not DV. It's not even DVCAM or DVCPRO. It *must* be 720 or it's not DV. See John Miller's excellent post above.

And yes it makes a significant difference by having 960 pixels on the chip and scaling that down to 720 for recording -- that's a sharper, better solution than previous methods which sacrificed vertical resolution.
__________________
CH

Search DV Info Net | 20 years of DVi | ...Tuesday is Soylent Green Day!
Chris Hurd is offline   Reply With Quote
Old May 28th, 2008, 08:30 PM   #15
Regular Crew
 
Join Date: Jul 2007
Location: Cph Denmark
Posts: 136
I believe the key word here is oversampling.

There is a video coverage from this years NAB where John Galt explains the theory of resolution. It is very technical and may be hard to grasp, but everyone interested in knowing how a image sensor works (or should work) would benefit from this knowledge. Especially if they are looking for a new camera.

http://www.freshdv.com/freshtv

Segment: Demystifying digital camera specifications

Last edited by Nik Skjoth; May 29th, 2008 at 08:02 AM.
Nik Skjoth is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK


DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon HDV and DV Camera Systems > Canon XL and GL Series DV Camcorders

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



All times are GMT -6. The time now is 05:07 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network