Track IR

[bn880 5]

Hi, I would like to ask if any of you have good information on whether or not Track IR systems are safe to use for extended periods of time. My concern is the IR source that keeps shining in your face while you have to lower ambient room lighting.

Any experts?

I have made this post on TrackIR forums which I'm sure will at least inspire them to look into the possibility of IR glasses, maybe some should be shipped with the product, who knows?

http://forums.naturalpoint.com/cgi-bin....=000377

Hopefully the brightness of the IR source is 10x lower than that of the monitor and I am worrying for no reason; or the IR level required to cause any retinal damage must be extreme... I just don't have the information as I don't own a TrackIR (yet) and do not know the IR source power intensity.

The whole theory is, if your eye is over exposed to some wavelength of light, you may get some parmanent damage, not sure what the effects of infra-red will be though.

[bn880 5]

No one has much info?

So far what I have found is not good news, most LED's sold over the counter are in the 800 to 1000nm wavelength range. that is very close to red visible light, and it certainly has potential to cause damamge which will not come from "heat". I assume TrackIR uses the over the counter LED's which at times can be extremely powerful when looking head on into them.

I certainly won't be getting a TrackIR until these guys explain what research they did and what kind of light this tracker emits.

Edit: Come one people, we have argued about the string theory here before, we must have some experts in this field as well.

[shadow 6]

Considering the TIR comes from the country of be all - sue all I'm not worried. I assume they've researched enough that I won't go blind using my TIR.

If you are worried about the light coming from a trackIR, are you worried about looking at a TV or using a remote for a tv or talking over a cell-phone or being near a cd-player too?

[bn880 5]

Shadow you are missing the theory behind it, I AM worried about the light coming from monitors and TV's, but at least my eyes see it and the pupil adjusts to the level of the light. With Infra Red you do not see it, eyes do not see it, and your pupil is too large and can over-expose your cornea.

Never for a second think that they researched it. If they did I would get a complete research document by now, have not checked the thread, but I'll bet it's not there.

[bn880 5]

WOHOO!

Jim Richardson

Quote[/b] ]Hello:

Sorry for the very late reply, we have been busy working on the next generation of trackIR system; do get your hopes up!

This message is the official NaturalPoint response to all the speculation and down right funny posts I have been reading over the last two days.

The trackIR operates by tracking reflected or emitted IR light that is imaged by a CMOS sensor. The sensor and emitters are tuned to 880nm, slightly above the visible spectrum, you can see them emit a slight glow when the room lights are off, this is the very upper end of the red spectrum. The sensor and IR LEDs are covered by a very special plastic that we custom designed with Bayer to block all light below 820nm, it passes all light above this point, it is called a band pass filter.

The LEDs emit at 880nm and are standard off the shelf IR LEDs, we run them all the time with the unit is turned on. There are 4 of them and they each have a total radiant output of about 23mw/sr, that is 23miliwats per ster radian. Total output power is NOT 4 X 23 mw/sr as the LEDS do not overlap exactly, they create a coverage pattern with slight overlap at the edges. Also, the LEDs to not emit a uniform brightness, they have an angle to half intensity, so the center of the overlapping LEDs is the SAME brightness as the center of each LEDs output, hope that makes sense.

Your eyes ARE sensitive to IR light, you can’t see it, but your eyes will register the “power†of the light, your pupils will shrink down as if you were looking at light in the visible spectrum. Remember, we are just slightly above red in the visible spectrum. You won’t feel your pupils getting smaller when our device turns on because we are a relatively low level of light for an average room condition. If you turn out all the lights in the room, put the unit about 1 foot away from your face and watch your eyes in a mirror, you will see your pupils contract, they are “seeing†the IR light.

As for the amount of power the LEDs output, it is many of times lower than simply going outside, not to mention on a bright sunny day. As I had seen posted before, we are a small fraction of the IR output from a normal incandescent light bulb. ANSI references spec ANSI Z 136.1 – 2000 for laser power emission, but we are not a laser, so in the back of the spec they reference ANSI/IESNA RP-27.1-96, which is the spec for lamp output, basically what we are and what ANSI says to use. Maximum exposure for our wavelength range, which is from 700nm to 1100nm is 10mw/cm2. To convert our power output, which is about 30mw/sr, we apply sr x 1cm2/distance2. Typical user distance is 18†or about 45cm (on the conservative side, most users are further away), so 30mw/2025 = .015mw/cm2. Needless to say, we are on the safe side!

Last thing I need to do is to confirm eyes do adjust to 880nm waveforms, but I believe they do indeed! Great... I will try to confirm this.

EDIT: Allright, I'm sure it is true since he suggests the little test.

[868 0]

Haven't you heard of parents telling their kids to not stay too close to the TVs?

Or

Articles and some medical journals suggesting that PC users need to rest their eyes from the monitors every 30~1 hour depending on the user?

Flip side:

A good eye muscle exercise is to find an object to focus on which is about 0.5 m away from you and find another which 1m plus.

Fix your eyes on them and try to focus as much as possible.

In turns, take 1 min on each object and keep doing it for 5 mins.

Then take a break (close your eyes or just keep away from any IR emitting products)

and eat alot of carrots

[mads bahrt 0]

Last thing I need to do is to confirm eyes do adjust to 880nm waveforms, but I believe they do indeed! Great... I will try to confirm this.

bn880 writing about 880nm light - i sense a conspiracy....

[EiZei 0]

I think he chose that on purpose since IR wavelenght is between 700nm and 1mm.

Anyways, doesn't electromagnetic radiation get less dangerous as the wavelenght becomes longer? Should'nt that make IR pretty safe?

[shadow 6]

Its what I assumed. The TIR is pretty harmless to your eyes.

As for taking a break every 30 or 60 minutes.

My eyes are certified for alot longer periods of use

Seriously, if you're wearing glasses maybe taking a break is more important as the glasses magnify all the light. I don't know.

I think you can safely buy and enjoy the TIR, bn880. As soon as you get it hooked up you'll forget all about this topic and enjoy yourself I think

As for that test looking at the TIR from close up, unless those 4 red LEDs are'nt strong enough they might aswell affect your pupils too because those LEDs are very much visible LEDs.

[bn880 5]

Flip side:

A good eye muscle exercise is to find an object to focus on which is about 0.5 m away from you and find another which 1m plus.

Fix your eyes on them and try to focus as much as possible.

In turns, take 1 min on each object and keep doing it for 5 mins.

Then take a break (close your eyes or just keep away from any IR emitting products)

and eat alot of carrots

Hehe, yes absolutely true, I was actually taking a walk yesterday looking at the squirrels (what else can you do here), and I was thinking of making a "suggestion" for this exercise in my missions upon being killed and waiting for respawn.

Shadow, I think so indeed, I did more research:

It seems that the eye IS sensitive to 880nm light, and even 1000nm light with less and less response however. There is almost a 10(consider area) fold difference in the response to blue light versus 900nm wavelengths by the iris(controling pupil size). This would suggest major possibility to damage from IR sources due to an over expanded iris and large pupil size, however, the energy of 900nm light is far smaller than that of 450nm blue light or other visible light. Hence I don't believe this kind of IR system will do much damage when compared to staring at a CRT monitor with dimmel lights in your room.

And by the way people, your room ambience should always be slightly brighter than your monitor's, to contract your iris and not over expose your retina.

[bn880 5]

I think he chose that on purpose since IR wavelenght is between 700nm and 1mm.

Anyways, doesn't electromagnetic radiation get less dangerous as the wavelenght becomes longer? Should'nt that make IR pretty safe?

Hehe,

and yes, I missed your post before, that's exactly what completes the circle and makes using TrackIR safe, coupled with a little retinal response to those waveforms along side with the usual response to the monitor light.

It's A'OK as far as I can tell.