On Mon, 2012-01-23 at 11:58 -0800, Joe Zeff wrote: > Motion Pictures are shown at 32 fps and nobody complains about > flickering Not quite. Films are usually shot at 24 frames per second, and shown back at a multiple of that. i.e. Each frame is usually strobed two or three times, so that you see 48 or 72 frames per second. That makes the strobing mostly unnoticeable to most people. Higher strobe rates could be used, but then you'd have a dimmer picture (the light being "on" for less per second, in total, than other rates). (I work in video/television production, and occasionally get to play with film, too. And just last night, had the pleasure of restoring a vintage 4-plate 16mm Steenbeck to working condition, to the delight of the owner.) > there are people who claim that anything less than 70 > fps on their monitor flickers. It depends on the monitor. CRTs have a short persistence screen that glows for X microseconds, and fades away. The persistence rate can be manufactured to suit how many frames per second the screen will be used at. Multiscan monitors are less optimal, it'll try to have a persistence rate long enough that the slowest scan speeds don't show motion blurred pictures, and so that highest scan rates don't flicker. But they don't always manage that, or manufacturers might just use an unsuitable tube. Hence why people notice how their computer monitor may flicker horribly at a 60 Hertz rate, yet their home TV doesn't noticeably flicker, but runs at the same 60 Hertz rate. Likewise for people in 50 Hertz countries. You can find, as I did, that some multiscan monitors are horrible at their fastest rate, giving me a migraine in moments. Yet okay at one of the middle rates. It's not just that you notice a flicker, but it's at a rate that disagrees with some brainwaves. Perhaps in conjunction with some other strobing source in the room (such as a beat pattern between the screen and fluorescent lighting, all running at different rates). I suppose the easiest way to give an analogy of that is with sound waves. Many people find fingernails scratched down a blackboard to be cringeworthy, yet other people are not bothered by them in the slightest. It's not a particularly loud sound, but it just happens to trigger an unpleasant reaction. And if you change the pitch of the squeal, a bit, and you change how that affects people. LCDs, and some other flat panel technologies, don't really strobe at you. The pixels are illuminated as required for the picture, and stay at that illumination until they're redrawn by the next frame. > I've always considered them the video equivalent of the audiophule, Was that a mispelling of audiofile, or a joke of audio+fool? ;-) > who claims he can hear the difference between regular cables and gold > ones even after a scope shows the output to be identical and he's seen > the display of the two sine waves. Well, some measurement techniques do not show up certain audio issues. But I agree that you just ain't gonna hear the difference between gold and aluminium audio wires, simply because they're different metals. Nor are you gonna hear various other silly differences. You can notice differences when there's resistance changes, as anything louder sounds slightly better (as a subjective comment). But then you can simply turn your volume control up a tad, and have exactly the same effect, without buying $400 speaker cables. Just where in the chain cables can have an effect depends on various things. Resistance in the speaker wires affects speaker damping (unwanted bass speaker resonance) as well as volume. Resistance and capacitance in the wiring between amplifiers and other decks can affect tone, depending on the design of the circuit around them (capacitance across high impedance circuitry can muffle the treble). But it'd have to be pretty awful cable to become seriously noticeable. A true audiophile knows that the weakest link is actually the speaker, itself. Transducers are not perfect, and some are far worse than others. And $400 cables aren't gonna get around whatever wiring has been used inside the cabinet, either. -- [tim@localhost ~]$ uname -r 2.6.27.25-78.2.56.fc9.i686 Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
