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Canon XL2 Question


Landon D. Parks

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Yes and no.

 

There's no reason to use an anamorphic adaptor with a XL2 because it uses the same pixels for 16:9 anamorphic and 4:3 -- because it basically starts out using a smaller area of the CCD for its 4:3 image and then using slightly less height but more width of the CCD to capture 16:9. The Sony PDX10 does something similar -- imagine overlaid 16:9 and 4:3 picture areas forming a cross-shape on the CCD.

 

Other cameras use most of the 4:3 CCD for 4:3 and then crop top & bottom to achieve 16:9, so the 4:3 image uses more pixels of the CCD. In that case, you'd use more of the pixels by using an anamorphic adaptor to get 16:9.

 

16:9 CCD cameras do the opposite and use less pixels for the 4:3 image.

 

But cameras like the XL2 and PDX10 split the difference so that 16:9 and 4:3 use the same number of total pixels of the CCD, sort of wasting the other areas of the CCD. You can't get the XL2 to use ALL the area of the squarish CCD for 4:3 so that using an anamorphic adaptor would maximize your pixel usage; you'd be squeezing a 16:9 image into the smaller 4:3 area that the camera uses when in 4:3 mode.

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You can't get the XL2 to use ALL the area of the squarish CCD for 4:3 so that using an anamorphic adaptor would maximize your pixel usage; you'd be squeezing a 16:9 image into the smaller 4:3 area that the camera uses when in 4:3 mode.

Interesting.

 

What would happen if you used a 16:9 anamorphic adapter while in 16:9 mode?

 

Because 4:3 and 16:9 modes use the same amount of pixels, I'd imagine the only difference would be that 16:9 mode would give you a slightly wider focal length?

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You'd get a squeezed-looking image on a 16:9 signal and 16:9 monitor than when unsqueezed into a letterboxed image, would be 2.35 : 1. But once you unsqueezed and letterboxed it, you'd be using less pixels for the picture area. But if the plan was to use this to transfer to 35mm anamorphic, you'd want to do all the post work with the squeezed 16:9 image and only create a letterboxed version for viewing copies.

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There's no reason to use an anamorphic adaptor with a XL2 because it uses the same pixels for 16:9 anamorphic and 4:3 --

So, it pulls somthing similare to what the Viper does? Thats pretty cool :ph34r: (I think its called "Pixel Shift" in the viper.

 

P.S)

U know, this camera really competes in resolution to the higher end pro cameras. XL2 in 16:9 mode has 16:9 approx. 460,000 pixels. Compared to, say SDX-900, which has 520,000 :huh: GO CANON :blink: :unsure:

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No, the Viper uses a system of "sub-pixels" in the CCD -- basically each pixel is made up of four sub-pixels. This allows them to be reconfigured for different aspect ratios while still being 1920 x 1080 pixels total. (Not sure I understand it completely either). However, a 2.35 image that uses 1920 x 1080 pixels will look stretched vertically on a 16:9 HD monitor unless the signal is converted to be displayed as a letterboxed image.

 

Don't forget that the SDX900 not only has larger CCD's (so less excessively deep focus) but can record 4:2:2 DVCPRO50, which is twice the data. Luminence / green may still only be 720 x 480 pixels as with any NTSC recording but the red and blue channels will have more resolution than in a 4:1:1 DV recording. Combine this with a better lens and you have a noticeably sharper and more detailed image.

 

I don't know if the Viper uses "pixel shift" -- that's a Canon trick where the green CCD is a half-pixel offset to give the impression of greater detail in the overall color image.

 

Some cameras like the Olympus "Super HD" experimental camera has two green CCD's, each 1920 x 1080 pixels, but are a half-pixel offset to create twice as much resolution in the green / luminence channel -- basically a physical form of 4:2:2 color subsampling. And the Arriscan film scanner has a 3K sensor but can offset it with each scan of the same frame in order to create 6K total resolution.

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I C.... Still pretty cool though ;)

 

I don't know if the Viper uses "pixel shift"

No, I dont think thats what its called. You are right, I was just on the XL2's website, and pixel shift is the offset of the green CCD.

 

Vipers is called:

 

Dynamic Pixel Management? technology
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