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eladh7 #1 28/04/2008 - 14h51

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hi
i wont to build the 4 LEDS cap.
to do this, i need to buy camera. the camera Microsoft LifeCam VX-6000
good to free-track on 4 LEDS cap?
and if i buy the camera Microsoft LifeCam VX-3000, there are big difference on 4 LEDS cap?
what the best choice of them?

i have another question.
my led-ir need 1.5 V and 100 mili amper.
the 4 led need 6 V.
I can connect the 4 led to the battery of 9 volt with resistor of 33 Ohm ?
Or the battery of 9 volt not enough strong for this..
The battery 9 volt  that I talk a rise she is this -
Posted Image
In which battery to use?

thanks to all  :)
Edited by eladh7 on 28/04/2008 at 14h53.
Deimos #2 29/04/2008 - 01h44

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For the camera choice, look trough "webcam compatibility tread" - i think both were mentioned there.
As for your setup, here are my comments:
*I'd recommend the use of 3 point setup rather than 4 point. They work the same, and in 3-point you have 1 less LED to power -> longer battery life.
*100mA is absolute maximum rating for this LED, not a long-term operating current. If you plan to remove the IR filter from camera (and i strongly recommend doing it), then 25mA should be more enough for the LEDS. If you plan to keep the  filter, then try powering LEDs with something about 60mA.


my led-ir need 1.5 V
the 4 led need 6 V.


Not exactly true. If you want to know how this exactly works, you can read my entire rant here:
http://forum.free-track.net/index.php?showtopic=700&message=5339
If not, just use the LED assembly wizard:
http://www.free-track.net/english/hardware/calcled/
This battery will be fine and should last quite long for a three LEDs setup. But make sure to calculate the resistor value using 3 point mode and about 60mA or 25mA forward current, depending on weather you want to keep the IR filter.
eladh7 #3 30/04/2008 - 12h24

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first , thnks for your reply.
ok, but why to remove the IR filter from camera? what is doing?
the IR filter not more good with him? because is filter for IR, no?  :huh:
Deimos #4 30/04/2008 - 16h27

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For filter removal instruction, go here:
http://www.free-track.net/english/hardware/webcam_filter_removal.php?PHPSESSID=e1b82764bedbfb1f0dff5725492fa768
I gues all microsoft cameras will have similar filter removal procedure. You'll also find some info about what the IR filter is and why is it worth removing. Make sure to see all of availible guides since some contain comparison photos taken by cameras with and without IR modding - it will give you a better idea of how huge the difference is.
eladh7 #5 30/04/2008 - 19h38

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so... on the camera Microsoft LifeCam VX-6000 what better, with this filter, or without him?
Deimos #6 30/04/2008 - 22h54

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Generally, FT always works better with IR LEDs, removed IR filter, and added visible light filter (cut from exposed photo film or a magnetic disk), since in such situation no visible light (daylight from behind the window, room illumination, etc) interferes with tracking - the camera can see only the IR LEDs Besides the camera will become very sensitive to IR light, so the LEDs won't have to be too bright (so the battery will last long). Otherwise (with the IR filter not removed and no visible light filter) your LEDs have to be really bright, and the room you're playing in should be dark. With the IR filter in place and additionally applied visible light filter the room can be brightly lit, but since the IR filter is still there only a fraction of IR light from LEDs gets to camera sensor, so you will need very bright LEDs (so the batteries won't last for long).
By the way it's the way that the original TrackIR works - it uses an infrared camera.
The only situation where you might want to keep the filter is when you're afraid to open up the camera :D But from what i've seen, removing filter in Microsoft cameras is very easy.
Edited by Deimos on 30/04/2008 at 23h05.
eladh7 #7 01/05/2008 - 00h06

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ok i decide. i buy the camera Microsoft LifeCam VX-6000. and i am not remove the IR filter, because i need the camera for the other things. but i put on my lens camera, passe IR filter. Like here -
Posted Image
its ok?
and i build the "4 point cap", because my Power supply is Transformer of 6v, Is not a battery.  so, i Will give to my led The maximum force.

thnks to all my Help me  ;)
Edited by eladh7 on 01/05/2008 at 00h09.
Deimos #8 01/05/2008 - 03h38

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A 6V regulated power should be ok, just make sure to select a regulated supply not a battery in the led assembly wizard when calculating resistor value. In that case you can try pushing the LEDs up to their maximum rating - 100mA, however i'd recommend something a bit lower - about 90mA instead. With LEDs powered with that much current, they'll be easily seen by the camera even trough the IR filter, so it should work perfectly :D
One advice though - don't use the 4-point setup. Use a 3-point instead.
For best results use default dimensions from Freetrack software - there are quite a few threads around the forums with questions about dimensions if you're still not sure how big your model should be.

Good luck :)

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