Xbox Kinnect user experiencing an afterimage. | Hacker News Reader

Xbox Kinnect user experiencing an afterimage.

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41 pointspiaskal20 comments

I am willing to bet that if these people didn't have some understanding of how the kinect works, they would not be experiencing this. Kind of similar to how small towns will occasionally complain about radiation from newly installed cell-towers, only to later realize the tower hasn't even been powered up yet.

As I understand the kinect's operation, it sends out a grid of dots, each dot being spread out by a few inches or so by a few feet away. In order to get a grid after-image, assuming that IR could do that, you'd have to be inches away from the device so that several different beams were all entering your eye through your pupil.

Now, it's possible there is something actually going on here, but my money is on psychosomatic. Seems way more plausible to me.

In order to get a grid after-image [...] you'd have to be inches away from the device so that several different beams were all entering your eye through your pupil.

Not necessarily. Kinect beams could reflect of your room onto your monitor, and back onto your retina. I think you might be able to achieve an afterimage in a laboratory, if you tried really hard:

- find some material that is fluorescent in visible light when irradiated by the IR that Kinect emits

- fill your room with it.

- seriously darken your room.

- play a game that has a very dark screen.

- stare at the screen for a couple of minutes while Kinect is active, keeping your eyes focused on one spot.

Of course, all of these are unlikely to be applicable here. Also, you will probably have lots of trouble finding that fluorescent material, if it exists at all; IR light is lower-energy than visible light, so the material will have to do multiple-photon absorption.

As I said, it's possible I'm wrong but I definitely think psychosomatic is far more likely. Particularly with the low amount of reports of this phenomenon.

None of that changes the fact that this is IR.

And I still find it impossible to believe that "spots resemble a vertical or slightly diagonal line and really resemble a sort of one dimensional test pattern (with various symbols, kinda like various geometric shapes). " would be visible via coincidence.

Psychosomatic. All the way. (I personally believe OP is a troll).

I wasn't attacking the conclusion, but only pointed out an error in his/her logic.

Considering that you can put on night-vision goggles and see the pattern that a Kinect puts out, and it's just dots, not shapes, I seriously doubt this guy's problems are actually from the Kinect.

You can also just your digital camera, my iphone 4's cam picks it up (it comes up as just normal white light).

I thought most digital cameras and webcams have IR filters.

For comparison, here's a youtube video of the dots the Kinect projects. http://www.youtube.com/watch?v=sM2-JQtd2Oc&feature=relat...

I think the "test pattern" is in the poster's imagination.

If you'll notice at the end of that video, the projector seems quite bright. If it is effecting the user's vision, a pattern could be because of eye motion, not the actual pattern projected.

I worry permanent effects of bright IR sources myself... I tend to avoid looking at Sick or Velodyne scanners when I'm around them too.

Lidar scanners use IR lasers. AFAIK the Kinect uses IR LED which wouldn't be nearly as harmful.

all sorts of afterimages are both plausible and common after looking at any sort of bright screen, after strenuous activity, or a combination of both. question is phrased as 'is this common and annoying thing about the world related to a new tech fad?'

I'm sure it's not related to this guy's problem, but I was surprised to find that Kinect puts out some visible light; you can easily see it when looking directly into the emitter, and if you get close enough (think centimeters) you can actually see (what I assume is) the dot pattern.

If you're worried, just get some sunglasses that can filter out infrared

Sunglasses filter UV. Off the opposite end of the visible spectrum.

Ok, so they wouldn't be called sunglasses. Either way, they have to exist somewhere. I'm pretty sure welder's masks block IR.

A welder's mask is much too dark to play a game with.

There are, however, IR cut-off filters. They're used in photography. See: http://en.wikipedia.org/wiki/Infrared_cut-off_filter

There are also sunglasses that filter out IR only, we wear them in the laser labs in school all the time.

An oxyacetylene welding mask would probably work, since they are less opaque than an arc welding mask.

/world runs out to buy kinect just to be able to participate in class action suit.

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