DVL-Digest 617 - Postings: Index DV Magazine frame mode cameras JVC GY-DV500 and 700 DV Magazine - "Perry" Robert posted: >Haven't seen your mag on newsstands here in Holland. Do you offer overseas subscriptions?< Enjoy it for free on www.dvlive.com It's posted a couple of weeks late and some of the articles never make it to pdf format, but hey who's complainin! Perry Mitchell Video Facilities http://www.perrybits.co.uk/ frame mode cameras - "Perry" Good try Eric, but not quite accurate I'm afraid! I'll explain how a normal camera works and then leave somebody else to explain EXACTLY how the XL-1 works! A normal camera actually does a progressive scan of every field, i.e. every 1/60 (PAL 1/50) of a second the whole image is scanned. The shutter time is thus usually 1/60 second (1/50). If you switch to a faster shutter, the CCD is 'shorted-out' (so that the charge cannot accumulate) for the start of the field, and then released for the stated shutter time to build charge normally. Whatever the shutter time, the accumulated charge is read out into an image store at the end of the field. The processor then averages line pairs (to improve sensitivity and noise) and reads these out into the system to form the interlaced field. It is important to remember that the CCD is an analog device and has restricted capacity to play tricks. Many of the modes on consumer cameras are actually done by processing the image rather than changing the CCD method of operation. A true progressive scan frame mode camera would scan the whole image for the stated shutter time, and then use this single image to form both fields of the video frame. A single field scan could be used and would give the equivalent of 180 deg shutter on a film camera. It would be necessary to remove the line pairing which would reduce sensitivity and the increased vertical resolution would result in unacceptable 'twitter' on the interlaced video. In practice, frame mode is commonly produced by using the normal scanning mode but discarding every other field and using a processor to produce an interpolated frame from the single field (which remember started life as a full frame anyway!) Perry Mitchell Video Facilities http://www.perrybits.co.uk/ JVC GY-DV500 and 700 - "Perry" Surf Reyes posted: >I've been off the list for way over a year and so may have missed info exchanges on this, but would anybody pont me to where I can immerse myself on users reports on the JVC GY-DV500 and GY-DV700 cameras?< Try Alexei's web site at: http://www.dvcentral.org/gy-dv500.html I've just tested the DV700W so when we get around to it, Alexei will probably add that as well. The bottom line is that it is very good for 16:9 but stick with the DV500 if you are going to shoot 4:3. The 700 sample I tested had just come from the BBC (PAL of course) and the color with 'Matrix On' was very good and much more natural than the default on the DV500. It also had the better viewfinder option. Perry Mitchell Video Facilities http://www.perrybits.co.uk/ (diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-) [up] |
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