Moderators: Dave Moll, Andrew Davie, Steve Anderson
I have heard that before, Volker, and perhaps with ordinary television systems that have scan rates at or close to the mains frequency there might be some such effect. But it seems to me that since the period of an NBTV frame at 12.5 fps is over 4 cycles of the 50 Hz mains frequency and if normal lighting had such an effect we would see a pattern of brightness variation over the displayed image. I have not heard of such a problem.DrZarkov wrote:Another reason for the common frame rates was (is) the flickering of the studio lights! If you use artifical light by light-bulbs you have a nasty stroboscopic effect if you use another framerate than those of your elctricity net.
Yes, I think that is a wonderful device for use as a "universal" scanner if it is responsive enough. It would be important to reduce moving mass as much as possible so that the motion of the mirror can accurately replicate the sawtooth vertical and lateral deflection waveforms.DrZarkov wrote:Have you seen the "loudspeaker scanner" on page 10 of the recent newsletter? In theory it should be ideal as an all purpose scanner for everything from 30 lines/12,5 up to 625 lines/25 frames (if any LED is fast enough for that...). Should be great for experiments.
DrZarkov wrote:Have you seen the "loudspeaker scanner" on page 10 of the recent newsletter?
DrZarkov wrote:....up to 625 lines/25 frames (if any LED is fast enough for that...).
DrZarkov wrote:Against the noise it's up to you, Steve: Put the device into a glas valve and evacuate it!
Stephen wrote:The camera could be responsive to a motion detector so that with no or little motion it would operate in a high resolution, low frame rate mode to capture detail. With any significant motion it would switch to a low resolution, high frame rate mode to capture smooth motion. The system could even be proportional so that frame rate would be proportional to rate of motion, and of course line rate would be inversely proportional to rate of motion.
This is just a "blue sky" proposal, but I do not see any inherent obstacles to developing such a system.
Users browsing this forum: No registered users and 27 guests