There is a lot of nonsense talked about resolution and pixel count, Canon's new XL2 camera has become part of that. The absolute pixel resolution does not say everything about the percieved resolution of the image by a human eye. This percieved resolution varies a lot by individualand what else is done to the data.
Secondly there is marketting hype and the Canon camera is full of it, along with an absence of real detail, such as frequency response or actual pixels recorded.
I live in PAL land and Canon have carefully NOT said what the vertical resolution of the camera is: they have implied it is the full PAL 576 lines but it does not actually say so anywhere. The same issue applies in both NTSC and PAL land for the horizontal resolution: they may well have a source CCD which is 950/960 pixels horizontally but the DV spec ONLY records 720 rectangular pixels (and 540 lines of frequency detail) so they are definitely processing this source data in the camera to put the picture on tape. Herein lies the devil and the detail: if they do this really well in the frequency domain, then they are effectively downconverting , in the digital domain, and ONLY horizontally. This should be good news as it will give a reduction in noise and should sharpen edges to their theoretical maximium, however, simple logic implies that dropping from 950 to 720 pixels is only a tiny improvement in source resolution and is likely to cause all sorts of artifacts: what if a line is sharp and vertical, how do two pixels portray it? Well we will see how good their engineers filters are!
So in a simplified answer to the first questions: yes 16:9 IS a COMPROMISE the broadcast boys decided on.
Tv guys have used super 16 for years and telecined this to 16:9 and many still do. ALL these standard definition systems end up with a SPATIAL resolution of 720 by 576 pixels in PAL land. These pixels ARE NOT square (like your computer) but are rectangular in shape. It was done as a clever bit of skulduggery by the TV boys to fit in with existing specifications. 1 bit in the data stream can say this data is 16:9 or 4:3 in ratio, but the actual total data content is the same: 720 per horizontal line(everywhere in the world!!!).
Then we get to questions of what is lost when you do a 5:1 compression: if the noise is low in the original source, suprisingly little. The coding schemes are now quite good and while they are NOT like a film sources image, for most of us they are good enough, on our TV's at any rate.
Many sources say that the actual films we see in cinemas are only about 800 lines of resolution horizontally and I have certainly seen films that looked like that. Most are much better and although XL2 results can be good they will never be as good as film. In my view film is still used widely because badly shot film can be "fixed" in telecine. Badly shot DV is C**p whatever else you do with it.
Well exposed and lit DV can look really good, but you need to be better at the art, not a beginner as is so often suggested.
This trick with the CCD is just a side issue dreamed up by the marketting boys: what matters is how good the Canon boys have processed 950 pixels to get the DV data on to tape, as 720 rectangular pixels and with a digital frequency response of 540 lines of percieved resolution. the XL1 did a damn good job, so if they repeat this the pictures may well be great!
Other questions come in then: is there ringing on sharp transition edges (we have all seen this around a persons face against a dark background). Do you see picture quality changes as the camera scene pans in any direction? Do you get contours enhanced? Why do we need skin tone correction in western coutries? does this apply to black and brown skins?
We all need to see real pictures to judge this, with test chart shots and frequency plots and we can see what they have thrown away to get it onto DV.
Then there is the real marketting question: if a little guy like JVC can invent and implement an MPEG HDV system: why cannot Canon? Notice I did not suggest the technical boys had anything to do with that question: it is obviosly possible, so what is scaring them?
Well the answer is down to your first question: most of us do not need HD: most of us just want 800 lines of REAL pixels, not bobbing about and at 50 FPS, because we would PERCIEVE that as REAL SHARP, and HDV might give us that, and we might not pay more for better....
Now let me see some screen shots of test charts and real images....
