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IR camera

Arayan

Arayan

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just one question: can a standard IR camera (or IR webcam) take an infrared beam at 1064 nm in the same way as an 808 one? This is because it's never specified the range of wavelengths in the camera's sensitivity.

:thanks:
Arayan
 





With some reservation, I'm going to say YES.

It will certainly vary by image sensor. A few things to keep in mind:

- On many cameras, IR is filtered out even when the sensor itself can image the wavelength. The filters used are not largely different than the slightly blue-tinted filters we stick on 532s.
- Cheaper / smaller cameras are more likely to be able to photograph IR in general, since they're less likely to have optical IR filtering.
- The flip side of this, is that cheaper / smaller cameras may be less likely to reach 1064, since they're designed with the understanding that they may not be used in conjunction with an IR filter.

So for example, I have a Rebel XTi that I've removed the internal IR filter from, and replace with a visible-spectrum-blocking / IR-pass filter. The filter I've added (right on top of the sensor) blocks everything below 1,000nm. I can take really nice IR shots with this mod. So while still a guess - I'm pretty sure my camera's sensor is picking up 1064. Given my experience with exposure time, I would find it hard to believe that the sensor was getting the images it gets, in the time those images take, with just the light that is above 1,000 but below 1,064.
 
(From Google) Typical spectral response from a CCD:

ccdSensorResponseGraph.gif
 
according to this graph, the sensitivity should be very very low at 1064 nm :undecided:
...If I understood well the meaning of "transmission"
 
Last edited:
rhd said:
So for example, I have a Rebel XTi that I've removed the internal IR filter from, and replace with a visible-spectrum-blocking / IR-pass filter. The filter I've added (right on top of the sensor) blocks everything below 1,000nm. I can take really nice IR shots with this mod.
Click to expand...

I've heard that cameras modified for IR can be used to see through peoples clothes. :whistle:
 
benmwv said:
I've heard that cameras modified for IR can be used to see through peoples clothes. :whistle:
Click to expand...

ROTFL

That was the old Sony "nightshot" type camera with 980nm illuminators (and they also modified for prevent that, when the news was spreading out, so actually no, it don't work)

Anyway, no, you was not totally "seeing through the clothes", technically speaking ..... was just that the CCD was not correctly filtered for mid IR, and some types of synthetic clothes, especially wet swimsuits (that was the main working ones) have different optical properties from visible to IR range (means, something that is opaque to visible, not necessarily is so much opaque to mid IRs :p :D), so the camera was able to reconstruct the image on the display as if the clothes was "half transparents" :p

But don't hope too much ..... all that what you can see (with the right type of fabric), are some shadows, or the contour of the underwears, for clothes ..... well, ok, maybe something more, with black wet swimsuits :p :D
 
Last edited:
rhd said:
So for example, I have a Rebel XTi that I've removed the internal IR filter from, and replace with a visible-spectrum-blocking / IR-pass filter. The filter I've added (right on top of the sensor) blocks everything below 1,000nm. I can take really nice IR shots with this mod. So while still a guess - I'm pretty sure my camera's sensor is picking up 1064. Given my experience with exposure time, I would find it hard to believe that the sensor was getting the images it gets, in the time those images take, with just the light that is above 1,000 but below 1,064.
Click to expand...

Are you able to see actual beams with that camera? My IR camera (same setup as yours, but a compact) can show the spots and show the illumination from IR sources, but beams are way too faint to be seen.
 
^ you're right, i said it in wrong way, sorry.

The built-in illuminator was 980nm, but the CCD was not correctly filtered til the start of mid-IR range, and the internal CCD was sensitive enough for "see" partially til that limit, so the image management software was able to amplify and "reconstruct" images also from that range (not exactly a thermographic camera, but enough for discriminate something decent through most of the light clothes ..... and, considering also that some fabric that looks totally opaque to visible light, are instead almost transparent to near-to-mid IR range ..... ;))

Anyway, usually you cannot get images better than this one (old Sony Nightshot camera, used with nightshot function enabled in full daylight)

237258_f520.jpg


And you can, actually, do the same thing with any camera with nightvision function and an add-on IR filter, like the Optek or Kaya PF4 or similar ones (and, for a cheap and quick test, also 2 or 3 layers of developed UNEXPOSED diapositive film in front of the objective :p :D)
 
Hey, glad you like it!
That is your typical 808nm 1W 9mm diode with a Aixiz glass lens.
 
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