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zwiebacksaege	#1 28/08/2007 - 11h31 Top
Class : Apprenti Posts : 28 Registered on : 27/08/2007 Off line	as stupid as always, i FIRST built my LED-assembly and THEN read the manual... :-) so i used 3mm LEDs instead of 5mm ones. is there a big difference between them and will there be a good advantage if i destroy my work and start new with 5mm or is there no big difference?
didja	#2 28/08/2007 - 11h50 Top
Class : Webmaster (admin) Posts : 1043 Registered on : 09/07/2007 Off line Www	I think it depends if your LEDs are IR or no.... If they're IR, there is no problem, but no-IR LEDs looks working better with FreeTrack in 5mm... Rémy
einsena	#3 28/08/2007 - 12h39 Top
Class : Apprenti Posts : 45 Registered on : 27/08/2007 Off line	reap what you sow :lol i think if the light radiated from your LEDs is large enough then there should be no problem. well, good thing those LEDs are cheap huh! here's another thing you might have not read yet, sand paper non IR LEDs. it'll distribute the light more evenly, for great justice!!!!11!! .
zwiebacksaege	#4 28/08/2007 - 12h53 Top
Class : Apprenti Posts : 28 Registered on : 27/08/2007 Off line	i use 3mm IR. so i think i will keep them on my construction. btw: i used sandpaper for the IR-LEDs and i think for them its not such a good idea :-)
spacefrog	#5 28/08/2007 - 14h13 Top
Class : Apprenti Posts : 12 Registered on : 22/08/2007 Off line	zwiebacksaege @ 28/08/2007 - 12h53 a dit: .....btw: i used sandpaper for the IR-LEDs and i think for them its not such a good idea :-) Hi zwiebacksaege, at first I thought the same thing too, but after I modded the cam to receive ir only, I can assure you that afterwards you HAVE to sand the LEDs in order to reduce the output on head on angle. Of course important is the resistance value too, mine lets the LED light visible evn with naked eye and that´s a little bit too much. (At my previous arrangement the ir light could be seen only with the cam). I use almost the whole bar of the Threshold to keep it in order.
tristan68	#6 28/08/2007 - 14h36 Top
Class : Electronicien en chef Posts : 651 Registered on : 10/07/2007 Off line	Hello spacefrog, zwiebacksaege Sanding the leds : - reduces light strength - increase their angle I had narrow beam IR leds , so i had to sand them flat to widen radiation angle, and it worked VERY well. In fact , angle is now so wide I don't really have to bother about fine led orientation. Also : sanding a visible radiation led as almost the same effect as sanding an IR led of about same characteristics. It's only we can't see IR, that's all. spacefrog you're right about led brightness, I had to cut the current to 1/4 of initial value, after removing the webcam IR filter. Led beam was just too bright. Now i use this modified webcam for freetrack with a piece of old radiographic film as visible light filter, and marker detection is ROCK SOLID without need of adjustment, whatever the lighting condition of my room. look for my report here to see what it looks like. cya. Edited by tristan68 on 28/08/2007 at 14h38.
zwiebacksaege	#7 28/08/2007 - 23h22 Top
Class : Apprenti Posts : 28 Registered on : 27/08/2007 Off line	my IR LEDs are not so bright i think. but the problem of FOV is not soo big. i'll try to modify it so that it works in 160x120 too. perhaps i can get some extra fps with that. @spacefrog: if your IR-LEDs emit light in visible range then the current is much too high. they will not last long in that way.
Kestrel	#8 29/08/2007 - 04h12 Top
Class : Webmaster (admin) Posts : 780 Registered on : 13/07/2007 Off line	zwiebacksaege @ 28/08/2007 - 23h22 a dit: @spacefrog: if your IR-LEDs emit light in visible range then the current is much too high. they will not last long in that way. Most IR leds produce some visible light while operating at a safe forward bias voltage but it's often hard to see. The SFH485P leds which are recommmended for Freetrack produce a substantial amount of visible light for an IR led. Support FreeTrack

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