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-   -   Buying your 1st cam? (https://www.dvinfo.net/forum/open-dv-discussion/18861-buying-your-1st-cam.html)

Frank Granovski December 27th, 2003 04:49 AM

Buying your 1st cam?
 
Read this great article by Dr. Peter Utz:

http://videoexpert.home.att.net/artic1/225ecamc.htm

Glenn Chan December 27th, 2003 12:26 PM

That articles assumes that the manufacturer's specs are trustworthy though...

Quote:

4. The higher the resolution the better. Higher resolution
means sharper pictures. Prosumer cameras start at about 400 lines
of horizontal resolution, professional models reach 700.
Pro cameras with any of the DV formats and the digibeta format can only hit 540 lines of resolution maximum. In some other measurement schemes (JVC) you might be able to get numbers higher than 700, but you can't compare numbers from different measurement schemes.

He also leaves out color accuracy.

Quote:

h) EIS --- Electronic Image Stabilization on prosumer cameras
reduces the shakes when working sans tripod.
Optical Image Stabilization is generally regarded as better than EIS.

Overall I would look at a camera from the end results it gives, not at technical details (which may not be accurate in the base of some measurements like lines of resolution). The things you want from a camera also differ depending on what the intended uses are. If you want a family video camera then size is important and a digibeta studio camera isn't a very good choice. There isn't a right answer for everyone.

Frank Granovski December 27th, 2003 04:53 PM

For the most part, I thought it was a good article. He also went into why consumer cam LUX claims are suspect.

Bill Pryor December 27th, 2003 05:06 PM

Glenn, the specs refer to the resolution of the camera, not what the attached or built-in deck records. The DSR500 does 850 lines of resolution. Of course, DVCAM only records just over 500, but that has nothing to do with the camera's resolution. This is in no way a misrepresentation of facts by manufacturers. The higher the resolution, the shaper the picture will be on the recording. My feeling is that because DV is a less wonderful format than DV50 or Digibeta, then you need to provide as much quality going in as you can, so the bigger the chips and the higher the resolution, the better the stuff will look.

Jeff Donald December 27th, 2003 05:41 PM

Resolution goes directly to the Signal to Noise Ratio and is very important in determining image quality. Resolution, along with chip size and pixel size are probably the three most significant factors determining image quality.

Glenn Chan December 27th, 2003 06:22 PM

The 540 lines of resolution maximum of DV formats is probably not measured the same way as the 850 lines of resolution spec.

The Sony brochure for the DSR500 (a camera with 16:9 CCDs) says that its effective picture elements are 980X494. It also says: "16:9 mode : 800 TV Lines, 4:3 mode : 850 TV Lines"
Judging by the number of pixels those numbers don't work, unless Sony is fudging the numbers. Perhaps they are saying that it takes some other sort of camera (i.e. some hypothetical analog camera) that does 800/850 lines of resolution to give a picture equivalent to the DSR500 in 16:9/4:3 mode.

Also, you can easily figure out that the 800/850 lines of resolution spec is not measured the same way as the 540lines maximum of DV formats. Asumming that the CCD can measure 980 black and white lines on a resolution chart in 4:3 mode, the DSR500 would get 735 lines of resolution after you divide by the aspect ratio (980 divided by 4/3). This is the way the 540 lines figure for DVCAM is calculated (720 divided by 4/3 = 540). The camera does not hit anywhere close to 735 lines of resolution (measured the normal way) since I was assuming all 980 CCD elements were being used for 4:3 mode. It probably uses 720 pixels horizontally for 4:3 mode (and ~960 for 16:9 mode).

Perhaps we should judge cameras by the pictures they produce, not by misleading specs.


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