Alan Roberts (BBC) tests the XF300 - 305

[Otis Grapsas]

Strange that Alan is not following PPH standard. 1800 lines horizontally is 1000 lines PPH horizontally. So it's 1000 lines PPH both horizontally and vertically on a chart.

 

[Razz16mm]

Strange that Alan is not following PPH standard. 1800 lines horizontally is 1000 lines PPH horizontally. So it's 1000 lines PPH both horizontally and vertically on a chart.

The standard for video camera resolution is TV lines, every line is counted. For still cameras the normal practice is to count line pairs. Line pairs would be half the TVL count for the same resolution. Since vertical resolution is the limiting factor, video cameras are usually measured and specified by their vertical TVL count. The Nyquist limit for vertical resolution for 1080p is generally considered to be around 900 TVL. Very few HD cameras come close to this. Most fall in the 600-750 TVL range.
Either way, it looks like Canon has done a superb job with the XF's. They have more than twice the alias and artifact free vertical resolution of any of the DSLR's.

 

[Mike Harvey]

My point is that if title of the article states: XDCAM EX vs. AVCCAM - it means comparing codecs not cameras. XDCAM goes to 50Mbs, AVCHD tops off at 24. If the article would compare EX1 with HMC150 I would call it a valid test, but as a codec comparison it compares the lowest of the XDCAM with the highest of the AVCCAM. I would like to see a split screen with EX1 and HMC150 side by side for 30-60 second shot in a couple of different lighting situation. I would also LOVE to see how the quality holds up after putting both fragments through some real post production, bot some frame grabs of possibly P or B frames of the long GOP. And no- AVCCAM is not the lowest of Panasonic- there is nothing else in this category.

But what would the point be of testing full XDCam against AVCHD? They are not competing products. XDCam-EX and AVCHD are.

 

[Otis Grapsas]

The standard for video camera resolution is TV lines, every line is counted. For still cameras the normal practice is to count line pairs. Line pairs would be half the TVL count for the same resolution. Since vertical resolution is the limiting factor, video cameras are usually measured and specified by their vertical TVL count. The Nyquist limit for vertical resolution for 1080p is generally considered to be around 900 TVL. Very few HD cameras come close to this. Most fall in the 600-750 TVL range.
Either way, it looks like Canon has done a superb job with the XF's. They have more than twice the alias and artifact free vertical resolution of any of the DSLR's.

You are confusing resolution terminology.

Horizontal resolultion in lines PPH=total lines/aspectratio. 1080 PPH horizontal resolution is 1920 horizontal lines and 960 line pairs per picture width. An ideal HD camera is 1920x1080 lines or 1080 lines PPH horizontally and 1080 lines PPH vertically.

Line pairs per mm are used in lenses and MTF. Lines pairs per mm does not make sense in video because the sensor size is different for each model. We don't care about that optical resolution on the sensor because magnification is different for each sensor, we only care about output resolution.

In still cameras the standard is lines PPH. The ISO resolution chart is lines PPH.

The standard is also lines PPH for video. We actually use the same charts that are used in photography for HD. All the numbers in every chart are in lines PPH. People see a limit at 800 lines and they simply say 800 lines vertical and horizontal resolution and most understand what that means. They never say 800 lines vertically and 1422 lines horizontally. It would be very confusing. When you hear 600 lines PPH horizontally and 700 lines PPH vertically, you know the camera is a little softer horizontally. When you hear the same in actual lines, 1067 lines horizontally and 700 lines vertically, you need a calculator

The only place where you will see TV lines is on the brochure of low resolution SD cameras. And we all know those figures are worth nothing, they are all 800lines at least

 

[Razz16mm]

PPH is lines Per Picture Height, essentially the same definition as the older TVL. TV engineers still call it TVL for the most part. Still the limiting factor for resolution of a camera or display system. Makes no sense to refer to PPH for horizontal resolution.
Whether you refer to lines or line pairs it represents the same test. Alternating black and white lines at various spatial frequencies.
MTF represents the relative percentage of contrast to which an optical system, including the sensor and everything in its optical path, can reproduce a given spatial frequency pattern of alternating black and white lines.
One can't really separate the resolution of a camera sensor from its optical system and ultimately MTF is what defines the image.
In any case the zone chart images for the Canon XF would be considered excellent for any 1080p HD video camera at any price or sensor size. I bet that camera will produce superbly detailed images with very little in the way of visible artifacts other than those introduced by the recording codec and compression.

 

[Otis Grapsas]

PPH is lines Per Picture Height, essentially the same definition as the older TVL. TV engineers still call it TVL for the most part. Still the limiting factor for resolution of a camera or display system. Makes no sense to refer to PPH for horizontal resolution.

It makes sense. There are vertical resolution trumpets in resolution charts and those are marked in horizontal lines PPH. Take a camera with a 1280x1080 DVCPROHD format. The horizontal resolution is inferior, limited to 720 lines PPH instead of 1080 PPH, you can't just ignore that.