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Subject: 
Re: Spybot studies: SetTxDirection() confusion
Newsgroups: 
lugnet.robotics.spybotics
Date: 
Fri, 7 Nov 2003 15:25:52 GMT
Viewed: 
5712 times
  
Yes, there are multiple IR emitters. Two in front at nearly 90 degree angles, one
in back, and a high-power one pointing up. Turns out my camera was only picking
up the high-power emitter.


I think these emitters are different wavelength, 940nm for the pointing up one,
880nm for the others. 940nm radiation is very close to red wavelength range and
is easily seen by cameras CCD, even though they generally include an IR filter
to get a good color balance with high IR lighting. 880nm on the contrary is
filtered out before reaching CCD.

An other difference lies in the shape of the IR-leds, the horizontal ones have a
flat top that spread out light, while the domed vertical one has a narrower beam
and appear brighter in that direction.

Philo



Message has 1 Reply:
  IR leds, was Re: Spybot studies: SetTxDirection() confusion
 
... Just reading an old post and saw my mistake: of course 880 nm is closer to red (650nm) than 940nm !!! Here is the correct text I should have sent : "I think these emitters are different wavelength, 880nm for the pointing up one, 940nm for the (...) (21 years ago, 14-Nov-03, to lugnet.robotics.spybotics)

Message is in Reply To:
  Re: Spybot studies: SetTxDirection() confusion
 
(...) Yes, there are multiple IR emitters. Two in front at nearly 90 degree angles, one in back, and a high-power one pointing up. Turns out my camera was only picking up the high-power emitter. I tried again with a different camera (the Vision (...) (21 years ago, 7-Nov-03, to lugnet.robotics.spybotics)

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