Electrical – a camera which records images at different wavelengths using optical filters

camera

I need to create images at a certain wavelength range(around 850-900 nm). For this a frequently cited solution is using optical filters. However I am not being able to understand the concept behind those.
A camera has image sensors which store charges, and then convert it into colored images using RGB optical filters. Now if I am to put up an optical filter that transmits wavelengths of only 850-900 nm, then what kind of image shall be captured?

From what I understand, since there is no RGB based wavelength in 850-900nm light, so the pixels will all record values (0,0,0) and we'll have just a black image.

Am I right? If not, please explain what exactly will happen and why? And is this method to capture a specific wavelength based image using optical filters the best one or even a possible one or I will have to go to the basics of image sensor development itself?

Best Answer

You use a black/white sensor that has no RGB filters.
Then, you put your IR filter in front of the camera. Now you have a camera that sees infrared only.

Most CMOS camera elements are IR sensitive and have an extra filter to remove IR so as not to make a mess when using RGB.

You can get black and white CMOS cameras commercially, some even have built in IR LEDs that can be used to "light up" the view field with IR.

Take a look around. You may even find a commercial unit with the correct IR filter already built in.