Vibrating eyeballs

[iondrive]

Sometimes I sing or hum when I'm using my old CRT and when I hit a certain pitch, I can see many dim horizontal bands moving up or down the screen. At one freq they are stable. Obviously my skull and eyeballs are vibrating at some multiple of the refresh rate. Has anyone else experienced this? If you want to try it, you need a CRT and it's more visible on an all-white screen. I haven't yet found a way to use this phenomenon to view 3d games but I'm working on it. Ha. I just thought I'ld post this and brighten someone's day.

--- iondrive ---

[cybereality]

Dude, you are just seeing the scanlines refreshing. I could see this constantly on any CRT and it drove me crazy.

Thats why I was happy when I got LCD, never going back.

[iondrive]

Hi cyber,

if you mean the vertical retrace, then no, that's not what I'm talking about. I can see that all the time since this CRT is old and I have it on max brightness/contrast. This is different. Wait, "scanlines refreshing"? Sounds like you mean horizontal scanlines since there are no vertical scanlines . I'm not sure what freq it happens at but I thought it was closer to the vertical freq rather than the horizontal freq (over thirty-something Khz). Oh, maybe you're right, taken as a group of scanlines, the period would be longer. Hmmm, thought about it some more and I still think it's a 60Hz refresh rate resonance thing.

Oh well, whatever, on to more thoughtworthy things.

If you're an animation fan, there are some cool ones on the DVD for "I am Legend".
Not to start a long conversation, but did you like "Sin City" and "The Spirit"?
Do you think the mentioned videos would be good candidates for a certain "cutout" style of 2d-3d video conversion?

EDIT: Oh I see, you mean the horizontal scanlines during the vertical retrace. Let me explain what I mean a little better. If you get your shutterglasses shuttering at 60 Hz and look at an old CRT TV that's on some channel, then you can usually see a dark horizontal band moving up or down the screen. That's something like what I see but there are a bunch of them and they are very faint. Maybe at a much higher freq I would see the scanlines refreshing but then the bands would be vertical. I think I would need superfast retinas for that though. That's all the time I want to spend on this.

2nd edit: OK, I wound up thinking about this some more and tried something. As I increase pitch, I see the bands, then I don't, then I see them again and again. I'm guessing that this corresponds to pitches at resonant freqs that are multiples of 60 Hz. It also explains why the number of bands increases from one pitch to the next resonant pitch. Yup, as pitch increases, bands start going down, then stabilize, then start going up. This also tells me it's syncing with the downward scan of the vertical trace. Also, distance from the monitor doesn't matter so it's not the monitor vibrating from my voice.

Oh brother, too much time on my hands and yet not enough.