CompuServe Thread

Regarding how digiview works: It doesn't grab a video field, incase you forgot, it takes multiple video fields for digiview to get all the information on a horizontal line. So this means the vertical sync has to be bang on from field to field. I would be more sure if my digiview would arrive and I had a manual to read. What I perceive to be a problem with line-sync cameras is they must decide to start the sync at the exact same spot in A.C. cycle. They probably use a zero crossing detector, since it would be more accurate then waiting until the incoming waveform crossed a certain voltage point, since this method would be very susceptable to voltage fluctuations during the digitizing process changing the period of the video field. I don't know how accurate the zero crossing detector method would be, but feel it would still be subject to a certain amount of jitter (for digiview, not monitoring purposes) and would still be slightly dependant on line voltage fluctuations (especially when something is starting up, the positive line peak may be at a different level than the negative line peak, causing a "bias" in when the zero crossing detector thinks it is crossing zero – I don't know if this is fact, but I can be good at b.s. at times!). As to the two models of the hitachi cameras (line lock and internal sync), they are both specified with 2:1 interlace. Some other specs for these cameras are: Automatic sensitivity control circuit, so the only necessary camera operation is focusing. Automatic beam Control – eliminates need for periodic readjustments of beam throughout life of camera tube. A white suppressor circuit ensures faithful reproduction on the video monitor, even for subjects with strong contrast. These cameras use a 2/3 inch vidicon tube, with 650 lines (at center) resolution. Minimum illumination is 3 lux (tungsten lamp, f1.6, AGC ON), with a recommended illumination of 30 lux or more. There are also versions of this camera with a 2/3 inch NewVidicon tube, with a resolution of 600 lines (at center), but with minimum illumination of 0.3 lux and recommended illumination of 3 lux or more (this newvidicon tube uses something called an EE lens). These cameras also have some form of screwdriver adjustment on the back labeled M. FOCUS (near – far). The models previously mentioned operate from 120 VAC. There are also models to operate from 24V ac. (not 240V). The brochure also mentions a number of lenses available, and there approximate picture angle, but they don't mention anything about minimum focal distances with any of them – something important for digitizing pictures, etc. I was told of somebody else who might be testing the Canon camera out, hopefully with DigiView, so I will be watching for that information. My problem with testing this stuff out, is I still haven't received DigiView, though that shouldn't be long coming, but also the store with the camera is over 3 hours away, so it is a bit of a long haul to drag the computer stuff there. Maybe one of the guys your way can convince a camera dealer to loan out the Canon to try it out for a weekend.