Why 1440 and not 1920 pixel like Sony... at DVinfo.net

Erwin Vanderhoydonks · June 23rd, 2008, 03:44 AM

Hi,
Perhaps this one is an easy one, but I was just wondering...
I'm just reading a lot about the Canon XL H1x because I'm considering a switch to FullHD.
Why is canon still using a 1440x1080 CCD instead of the 1920x1080 CCD (or CMOS) like Sony ?
What is the difference in image quality (IQ) ?
On the Canon XL1 they also don't use the full PAL resolution. The use something like pixelshift. As far as I know the FullHD resolution is 1920x1080i/p. But the CCD used in the XL H1x is not the Full resolution. Is there no lose in IQ ?

Thanks for the feedback...

Chris Hurd · June 23rd, 2008, 05:39 AM

The sensor width of 1440 anamorphic photosites matches the resolution of the recording format (HDV, also the same for HDCAM). Horizontal-axis Pixel Shift provides a significant boost in resolution which more than makes up for any perceived difference in scaling 1440 anamorphic to 1920 square. See my article Canon XL H1 Image Sensors, DSP and Frame Rates for more information.

Remember that CCD and CMOS image sensors are analog devices; since there's a conversion process from analog to digital, it's not necessary for the number of photosites to equal the number of pixels in the recording format, but in the XL and XH series camcorders this is indeed the case plus there's H-axis Pixel Shift on top of that. The new H1S and H1A models have the same CCD block as the previous XL H1 and XH camcorders for two reasons: first, nothing is wrong with the image they put out, therefore no need to change anything; and second, it's much more important for the image of all four current models (XL H1S / H1A and XH G1 / A1) to match each other perfectly; changing the CCD block on the new XL cameras would have prevented that.

Image "quality" is determined by many more factors other than resolution, but to answer your question: no, there is no loss in image quality. The resolution of the CCD block in the Canon XL / XH series camcorders exceeds the resolution of the HDV (and HDCAM and DVCPRO HD and XDCAM HD) recording formats. Hope this helps,

Erwin Vanderhoydonks · June 23rd, 2008, 05:53 AM

Quote:

Originally Posted by Chris Hurd

See my article Canon XL H1 Image Sensors, DSP and Frame Rates for ...
Hope this helps,

Thanks for the quick feedback and for the link to the article.

Alex Williams · June 23rd, 2008, 09:03 PM

How does the Canon series "exceed the resolution of HDV (and HDCAM and DVCPRO HD and XDCAM HD) recording formats"?

Chris Hurd · June 23rd, 2008, 10:04 PM

Because the res of the sensors on the CCD block is native 1440 x 1080 anamorphic, same as those recording formats (actually greater than what DVCPRO HD records to tape). H-axis Pixel Shift provides a resolution boost to about 1920 x 1080, which is greater than the res of those recording formats. That's how. Basically what I just said in my post above.

Min Lee · June 24th, 2008, 05:58 PM

Chris
A bit of a side note, I read on your article "Canon does not manufacture CCD image sensors, and they will not divulge the identity of the vendor supplying them." I took apart a broken ZR40 and on the back of the sensor read SONY. I don't know if that's the case with the XLs but perhaps the the canon sensor are not that much unlike the sony sensors after all, at least in the case of older consumer cameras.

Alex Williams · June 24th, 2008, 08:28 PM

I was under the impression that the XDCAM HD resolution at the imaging device level was better than Canon's?

Chris Hurd · June 24th, 2008, 10:39 PM

Quote:

Originally Posted by Min Lee

I took apart a broken ZR40 and on the back of the sensor read SONY. I don't know if that's the case with the XLs...

That was my impression as well, although I believe the older XL1 / XL1S chips might have been Panasonic.

Any photos of your ZR40 guts? Stuff like that is always interesting.

Quote:

Originally Posted by Alex Williams

...XDCAM HD resolution at the imaging device level was better than Canon's?

Could be, but I was talking about recording resolution (which is 1440 wide for XDCAM HD).

Min Lee · June 25th, 2008, 11:12 PM

Here's a link of pics of the ZR
http://www.ocf.berkeley.edu/~mdlee/zr/

anyone interested in buying a used ZR as is :]

Marty Hudzik · June 26th, 2008, 06:13 AM

For some reason I find it funny/interesting that the printed circuit boards in that torn apart ZR camera look like you just took some old PC cards and snuck them into the picture. I don't know why but I was envisioning the guts of these cameras to look more "high-tech" and not quite so.....normal. Guess this is a reminder that these cameras really are mini computers with lenses and media to record to.

Greg Boston · June 26th, 2008, 10:57 AM

Quote:

Originally Posted by Chris Hurd

Could be, but I was talking about recording resolution (which is 1440 wide for XDCAM HD).

The sensors on the PDW-F series XDCAM HD are indeed 1440x1080 and are recorded as such, whereas the EX cameras have 1920x1080 native CMOS which get recorded as 1920x1080. The forthcoming PDW-700 has 1920x1080 CCD sensors (the optical block comes from the HDC-1500 studio camera).

As Chris points out, it's not just one part of the process that makes a pretty picture. The glass in front of those sensors is probably one of the most important aspects of the chain.

-gb-

Michael Galvan · June 26th, 2008, 12:30 PM

Quote:

Originally Posted by Greg Boston

As Chris points out, it's not just one part of the process that makes a pretty picture. The glass in front of those sensors is probably one of the most important aspects of the chain.

-gb-

Yes, I just did a XLH1/mini35/Zeiss Superspeed Cineprimes/Uncompressed capture film shoot this past weekend for a short film competition.

Once I clear with the director, I will post up some clips of the short to show the XL at its higher-end of usage ... I think you'll like the image a lot :)

Erwin Vanderhoydonks · June 30th, 2008, 05:34 AM

Quote:

Originally Posted by Chris Hurd

Image "quality" is determined by many more factors other than resolution, but to answer your question: no, there is no loss in image quality. The resolution of the CCD block in the Canon XL / XH series camcorders exceeds the resolution of the HDV (and HDCAM and DVCPRO HD and XDCAM HD) recording formats. Hope this helps,

But does it also exceeds the IQ and resolution of the Sony XDCAM EX-1 or EX-3?

Chris Hurd · June 30th, 2008, 06:53 AM

Quote:

Originally Posted by Erwin Vanderhoydonks

But does it also exceed the IQ and resolution of the Sony XDCAM EX-1 or EX-3?

The differences between Canon XL and Sony EX have more to do with workflow and format than anything else. If you're trying to make a decision between these cameras, you need to choose the particular format (HDV vs. XDCAM) and workflow (tape vs. flash) that is most appealing to you. Any real or perceived differences in "image quality" or resolution are fully outweighed by the far more important considerations of format and workflow. You will not be disappointed by the image quality or resolution of either camera system, but the choice of format and workflow will have a far greater and much more significant impact on what you do. You need to set aside this concern about "image quality" -- both systems are superb and their differences in this regard are trivial -- and focus instead about how you're going to handle your production and post-production workflows, for that is the *real* difference between the two systems. Pick the one which most appeals to you.

Michael Galvan · June 30th, 2008, 07:32 AM

I agree here ... the cameras are so close in terms of technical "image quality," I think workflow is the big decider here.

I'll be shooting a feature late this summer, and I've decided to go with the XL-H1S with mini35/uncompressed capture and use tape as backup.

I've used both XL and EX cameras, and both are great. You really need to feel out workflow and ergonomics, which are deciders in my opinion ...

June 23rd, 2008, 03:44 AM	#1
Erwin Vanderhoydonks Regular Crew Join Date: Jul 2005 Location: Belgium (Blaasveld - Willebroek) Posts: 35	Why 1440 and not 1920 pixel like Sony... Hi, Perhaps this one is an easy one, but I was just wondering... I'm just reading a lot about the Canon XL H1x because I'm considering a switch to FullHD. Why is canon still using a 1440x1080 CCD instead of the 1920x1080 CCD (or CMOS) like Sony ? What is the difference in image quality (IQ) ? On the Canon XL1 they also don't use the full PAL resolution. The use something like pixelshift. As far as I know the FullHD resolution is 1920x1080i/p. But the CCD used in the XL H1x is not the Full resolution. Is there no lose in IQ ? Thanks for the feedback...

June 23rd, 2008, 05:39 AM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	The sensor width of 1440 anamorphic photosites matches the resolution of the recording format (HDV, also the same for HDCAM). Horizontal-axis Pixel Shift provides a significant boost in resolution which more than makes up for any perceived difference in scaling 1440 anamorphic to 1920 square. See my article Canon XL H1 Image Sensors, DSP and Frame Rates for more information. Remember that CCD and CMOS image sensors are analog devices; since there's a conversion process from analog to digital, it's not necessary for the number of photosites to equal the number of pixels in the recording format, but in the XL and XH series camcorders this is indeed the case plus there's H-axis Pixel Shift on top of that. The new H1S and H1A models have the same CCD block as the previous XL H1 and XH camcorders for two reasons: first, nothing is wrong with the image they put out, therefore no need to change anything; and second, it's much more important for the image of all four current models (XL H1S / H1A and XH G1 / A1) to match each other perfectly; changing the CCD block on the new XL cameras would have prevented that. Image "quality" is determined by many more factors other than resolution, but to answer your question: no, there is no loss in image quality. The resolution of the CCD block in the Canon XL / XH series camcorders exceeds the resolution of the HDV (and HDCAM and DVCPRO HD and XDCAM HD) recording formats. Hope this helps, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

June 23rd, 2008, 10:04 PM	#5
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Because the res of the sensors on the CCD block is native 1440 x 1080 anamorphic, same as those recording formats (actually greater than what DVCPRO HD records to tape). H-axis Pixel Shift provides a resolution boost to about 1920 x 1080, which is greater than the res of those recording formats. That's how. Basically what I just said in my post above. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

June 30th, 2008, 07:32 AM	#15
Michael Galvan Major Player Join Date: Sep 2004 Location: New York, NY Posts: 775	I agree here ... the cameras are so close in terms of technical "image quality," I think workflow is the big decider here. I'll be shooting a feature late this summer, and I've decided to go with the XL-H1S with mini35/uncompressed capture and use tape as backup. I've used both XL and EX cameras, and both are great. You really need to feel out workflow and ergonomics, which are deciders in my opinion ... __________________ www.michaelgalvan.com www.screenanthology.com

June 23rd, 2008, 09:03 PM	#4
Alex Williams New Boot Join Date: May 2008 Location: Stratford CT Posts: 14	How does the Canon series "exceed the resolution of HDV (and HDCAM and DVCPRO HD and XDCAM HD) recording formats"?

June 24th, 2008, 05:58 PM	#6
Min Lee Major Player Join Date: Sep 2005 Location: San Francisco, CA Posts: 200	Chris A bit of a side note, I read on your article "Canon does not manufacture CCD image sensors, and they will not divulge the identity of the vendor supplying them." I took apart a broken ZR40 and on the back of the sensor read SONY. I don't know if that's the case with the XLs but perhaps the the canon sensor are not that much unlike the sony sensors after all, at least in the case of older consumer cameras.

June 24th, 2008, 08:28 PM	#7
Alex Williams New Boot Join Date: May 2008 Location: Stratford CT Posts: 14	I was under the impression that the XDCAM HD resolution at the imaging device level was better than Canon's?

June 25th, 2008, 11:12 PM	#9
Min Lee Major Player Join Date: Sep 2005 Location: San Francisco, CA Posts: 200	Here's a link of pics of the ZR http://www.ocf.berkeley.edu/~mdlee/zr/ anyone interested in buying a used ZR as is :]

June 26th, 2008, 06:13 AM	#10
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	For some reason I find it funny/interesting that the printed circuit boards in that torn apart ZR camera look like you just took some old PC cards and snuck them into the picture. I don't know why but I was envisioning the guts of these cameras to look more "high-tech" and not quite so.....normal. Guess this is a reminder that these cameras really are mini computers with lenses and media to record to.