IR vs Thermal

**Juliemac** · 09-09-2005, 08:50 AM

I have tried out the IR camera I got the other day. Not QUITE what I expected. I sorta thought I would be like super woman, being able to see through fog, rain, snow etc.

Can some one describe for us the difference between the IR and Thermal cameras?

Might make a good sticky!

Julie

**mushin** · 09-09-2005, 11:27 AM

The difference is the frequency of IR captured. IR from most human-comfortable temperature sources are a much lower frequency than what will be captured by cheap IR cams.

**Juliemac** · 09-09-2005, 12:40 PM

Ok. Good explaination.
Would increasing the IR source help penetrate the fog (etc) while driving?
It seems the truck that disappeared into the fog on camera did so at the same time my eyss lost contact.

**Change** · 09-09-2005, 01:16 PM

Unlikely. Near IR cameras (like what you have) work off of reflected energy, just like a regular camera. It's just a wavelength our eyes can't see. Far IR cameras (thermal) work on emitted energy (heat produced by an object). If you pump up the near-IR light source, it's just going to reflect off of the fog like your headlights do. (Though the IR might make it a bit farther through the fog than headlights, it still won't penetrate much further)

Good explanation of the different IR regions: http://en.wikipedia.org/wiki/Infrared

**Bob T1** · 09-09-2005, 07:59 PM

The one I saw on a helo used cryogenic cooling -very cold. I think it reduces the thermal noise in the detector so it can be used in that range. Very expensive.

**Punisher** · 10-02-2005, 11:28 PM

yea I can imagine that.. getting a couple IR LEDs.. like ones the size of the 5w Luxeon Star LED's.. lol..

Ok, so what if it was clear out.. no fog/snow/rain?

I am interested in a forward looking camera for night driving.. something that will help me spot down the road.. would more IR power help in clear situations?