pic: IR captured in photo (4 IR LEDs @.1A DC ea)



Photo of 4ea 940nm IR LEDs ea illuminated @.11 A DC (5-1.34v)/33ohms
DC=maximum average optical power for photography

(pulsing at 40kHz+burst @1 or 2mS @100Hz
reduces proportionally avg optical power by the duty cycle
= difficult for some camera’s to “see” enough 940nm IR)

Yup make yourself an array of them and you have a flashlight that only your camera can see. = really bootleg night vision

Ehat camera did you use for this picture? My camera can hardly see anything when pointed at the beacon.

any old camcorder will see IR remotes and LEDs

try turning the lights off, or hold the LED closer to the camera - BTW this is a good way to check and see if they are working

Somebody else posted that newer cameras have better filters and block more of the IR

Camera used: Olympus 3040, digital, 3 megapixel, flash off, macro focus on

This photo was taken with an IR LED powered from a
5 VDC voltage source drawing .11A (33 ohm kit current limit resistor)
i.e. 100% ON duty cycle…
to make it easy for the digital camera to see.

See my other IR Beacon photos in the gallery
showing the much dimmer (but visible) LED illumination when pulsed/burst
<1 mS burst of 40 KHz pulses, & low duty 100Hz rep>

emitter 0:
pulsed at 40 kHz (50-50 duty square wave)
burst for 40 cycles = 1mS (total ON time = 500uS)
and 100 Hz repetition rate (total Off time = 9500uS)
500*100/(9500+500) = 5% ON duty time

use emitter 1 (to improve cameras ability to see IR a bit)
80 cycles = 2mS (total ON time = (.52mS) =1000uS)
and 100 Hz repetition rate (total Off time = 9000uS)
1000
100/(9000+10000) = 10% ON duty time