Seek thermal imagers can see SWIR

[Fraser]

Ben321,

Purely out of interest, can you tell us what you are wanting to image in the SWIR band. The reason I ask is that I have not had much use for a SWIR camera to date as my NIR requirements are well covered by common CCD and CMOS cameras. I do not experiment with Lasers either. SWIR always struck me as quite an exotic area of the spectrum, above common NIR and below the common thermal wavelengths. I know that it can see through water vapour and is a reflected energy waveband but outside of factory production lines and art investigations, I could not see a use for it in everyday life. Laser beam shape profiling seems to be a popular use though.

I think you mentioned something about 'Night Glow' or similar once ?

Fraser

[Ben321]

Sorry for taking so long to get back to you guys. Here's a picture I took through a piece of glass (a glass salad bowl) that is about 1/4 inch thick (much thicker than the glass envelope of the halogen bulb itself). Now theoretically, if this was all just LWIR radiation, the filament and the glass bulb would be attenuated equally by my glass bowl, making them both dimmer (until the auto-levels function of the seek camera brought them back to normal levels, making them look like just like in the picture from my opening post in this thread). But that's not what I see. The hot glass bulb is not visible AT ALL through this glass bowl (complete LWIR attenuation), but the filament is still clearly visible. Clearly, much shorter wavelengths are being detected by my Seek Compact Pro. I would doubt that it's MWIR, because like with LWIR, the MWIR band is absorbed by normal glass. SWIR wavelengths though (up to about 2000nm) can pass through most ordinary types glass without much attenuation (and slightly longer wavelengths than that with increasing attenuation as the wavelength gets longer).

One thing I know it's not is in NIR band (like 800 to 900nm), because when I point my TV remote control (which uses an IR LED, that I think is somewhere around 850nm) at my Seek Compact Pro and press a button on it, my Seek doesn't see it at all. So the wavelength from this filament that is being detected by my Seek, must be somewhere in the SWIR range (somewhere between 1000nm and 2000nm probably).