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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... |
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, |
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How does the Canon series "exceed the resolution of HDV (and HDCAM and DVCPRO HD and XDCAM HD) recording formats"?
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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.
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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. |
I was under the impression that the XDCAM HD resolution at the imaging device level was better than Canon's?
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Any photos of your ZR40 guts? Stuff like that is always interesting. Quote:
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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 :] |
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.
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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- |
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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 :) |
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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 ... |
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Format : HDV and XDCAM. For the moment I use PAL DV format. The only thing I see as a big difference between DHV and XDCAM is the output format. Or am I wrong ? Workflow : Tape or Flash. As I said, for the moment I use Tape. Nothing wrong with it for the moment. Only that I have to read every tape again after the shooting. And otherwise I have to carry my macbook pro to copy onstage the SxS cards. Now I have to change a tape. So the only thing is the format : HDV or XDCAM ? Any help here... Thanks. |
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HDV vs. XDCAM EX? Well XDCAM EX is a technically superior format, being everything HDV is, only being native full raster, higher bitrate, and variable at that. But that being said, Canon HDV does the job as well, its just a matter again of what you will be shooting as the workflow seems to be the decider. Tape or SxS cards ... The plus with the Canon is that there is tape along with the HD-SDI, so you have the option to go tapeless as well ... I use an AJA IO HD to record superb footage from the HD-SDI, far superior to what laid to tape or SxS card ... but then that's a different type of shooting altogether. I guess I'm just saying you can have both tape and tapeless with the Canon (albiet higher priced though). |
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After reading all of this, I'll think Igo for the Canon XL H1A. I'm used to the XL1, the body is great and the XL H1A has the 'same' body. And tape gives the same result and same workflow, so if my XL1 can't be fixed, this is the one to go for... |
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But you CAN still go tapeless via a Firestore device. But yes, I think you'll acclimate well to the camera if you are used to the XL series ... |
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Firestore is an option... But first getting used to the camera and later... Thanks for your feedback... |
Remember the firestore is gong to only record HDV also, so there is no benefit image wise to using it. It will look identical to tape images. However it could be a great benefit to going tapeless.
I'd bet there will soon be devices capable of recording HDV streams to CF cards so don't rush into the firestore, which is hard drive based system, unless you have to. These can still be prone to failing since there are still moving parts. Good Luck. I just wanted to make sure you understood the benefits (or lack of) of the firestore. |
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I am more inclined to think an image produced by a cam is only as strong as it's weakest part. I am still on the fence about HD and will wait to see lens, sensor, format, and shutter etc. to all be at the same level before I buy.
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You'll be waiting a long time then. ;)
There's no such thing as the perfect camera where all it's parts are equal. At least not the in the price range you're shopping for. |
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CF recording of HDV has already arrived if you count the Sony device that is bundled with the Z7, S270. |
Cf for hdv is indeed available to Sony z7 users only. However it has been confirmed this device works with the Canon A1. However it is not for sale separately yet.
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