Emitters LD274-3
Peak wavelength 950nm
VF max (IF=100mA) 1.3V
VR max 5V
Surge current (t=10µs) 3A
IF (max) 100mA
Beam angle 20°
Power dissipation 165mW
(IF=100mA) tp = 20ms 80mW/sr

this are the spec’s of the diode’s i want to use in my table.
i just want to know if and how to modify the lens of my webcam for that wavelenght.

You don’t , you just block out light in the sub 750nm spectre (visible light).You do that by firstly removing the IR filter inside your camera , it’s a small black piece of material over the lens or under it.
And then you place over the lens either a sheet of overexposed photo negative , or the inside material from a floopy disk.

I’d recomend floopy , it’s just easyer to get and give off better results.

but won’t there be other signals from above ore just below my specific waveleght that will interfere with my IR light?

Only bright sunlight , you could buy a bandpass filter from Thorlabs for your specific wavelenght , but that’s only if your table would be put next to a window.

it would be in a location just below a skywindow and about 4-5m from a normal reasonably sized window.
maybe this matters: the skywindow is pointing South-East and the normal window is pointed south-west.

Hi,

Emitters LD274-3
Peak wavelength 950nm
VF max (IF=100mA) 1.3V
VR max 5V
Surge current (t=10µs) 3A
IF (max) 100mA
Beam angle 20°
Power dissipation 165mW
(IF=100mA) tp = 20ms 80mW/sr

Is the LED a good choice?

The Price in Germay is 0,198 €, other LED’s are to be high in price!

greets
Mahon

i could buy those leds at 19 cent’s a piece so it’s still a little more cheaper here in Belgium

are you using the Emitters LD274-3 LED’s in your Table?

greets
Mahon

I’m not sure about that ld274-3 it just told me that it was called ld274.

i will use those led’s in my table but i don’t have those yet, so we’ll have to wait and see. I’ll probably will post some result after i get back from my holiday