IR by Digital Camera - Electronic Circuits Projects Diagrams Free

Abeer_engjbr · 23rd May 2008, 02:06 PM

Hi,

I want to know why we can see IR through digital camera? I know that we can't see IR because it's not in the visible range.

Thank you.

**3v0** · 23rd May 2008, 03:23 PM

The IR the camera can see is in the visual range of the image sensor. The image sensor is read by a micro computer/controller and stored in the camera memory.

As I understand it, you would see even more IR if the cameras did not use a IR filter between the lense and the sensor.

HTH

Abeer_engjbr · 23rd May 2008, 03:58 PM

Do you mean that the IR invisible range is considered visible to the camera? Is that what you ment by visual range of the image sensor? and what do you mean by "stored in the camera memory"?

blueroomelectronics · 23rd May 2008, 04:08 PM

It's an optical IR filter, some people even pull them out of their cameras to take IR photos.
http://www.abe.msstate.edu/~jwooten/camera/lense.html

**3v0** · 23rd May 2008, 05:03 PM

[quote=Abeer_engjbr;314535]Do you mean that the IR invisible range is considered visible to the camera? Is that what you ment by visual range of the image sensor?
[quote] Somewhat yes and Yes.

Quote:

Originally Posted by Abeer_engjbr

and what do you mean by "stored in the camera memory"?

You can think of a camera sensor as a special type of memory chip. Light striking the chip changes the value of each cell. A computer in the camera reads these cells to get the picture. The data/picture is then stored in the camera flash memory. This is a very simplistic version. If you want more details read Digital camera

crutschow · 23rd May 2008, 10:44 PM

IR covers a considerable range of wavelengths. The typical silicon sensor, such as in a camera can see to about 0.9-1um wavelength. (0.7um is about the limit of the human eye). IR sensors designed for sensitive night vision typically operate in the long wavelenght 5um to 10um region (objects at room temperature radiate most strongly in the 10um region). To operate at these long wavelength regions with best sensitivity requires cooled detectors, but some of the new thermal type detectors have remarkeably good sensitivity operating uncooled at room temperature.

A natural IR detector example is a rattlesnake, which has two IR thermal sensors, one in each of the pits between its eyes and the nostril. Since a rattlesnake is cold-blooded the sensors are naturally somewhat cool as compared to any warm-blooded prey which improves sensitivity. Probably don't work so well on a hot day.

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23rd May 2008, 02:06 PM	(permalink)
Abeer_engjbr	IR by Digital Camera Hi, I want to know why we can see IR through digital camera? I know that we can't see IR because it's not in the visible range. Thank you.

23rd May 2008, 03:23 PM	(permalink)
3v0	The IR the camera can see is in the visual range of the image sensor. The image sensor is read by a micro computer/controller and stored in the camera memory. As I understand it, you would see even more IR if the cameras did not use a IR filter between the lense and the sensor. HTH __________________ search engine for electronic parts Junebug USB PIC programmer kit., USB Bit Wacker, Homepage The 15 Minute Printed Circuit Board! (+drill time) Last edited by 3v0; 23rd May 2008 at 03:24 PM.

23rd May 2008, 03:58 PM	(permalink)
Abeer_engjbr	Do you mean that the IR invisible range is considered visible to the camera? Is that what you ment by visual range of the image sensor? and what do you mean by "stored in the camera memory"?

23rd May 2008, 04:08 PM	(permalink)
blueroomelectronics	It's an optical IR filter, some people even pull them out of their cameras to take IR photos. http://www.abe.msstate.edu/~jwooten/camera/lense.html __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

23rd May 2008, 10:44 PM	(permalink)
crutschow	IR covers a considerable range of wavelengths. The typical silicon sensor, such as in a camera can see to about 0.9-1um wavelength. (0.7um is about the limit of the human eye). IR sensors designed for sensitive night vision typically operate in the long wavelenght 5um to 10um region (objects at room temperature radiate most strongly in the 10um region). To operate at these long wavelength regions with best sensitivity requires cooled detectors, but some of the new thermal type detectors have remarkeably good sensitivity operating uncooled at room temperature. A natural IR detector example is a rattlesnake, which has two IR thermal sensors, one in each of the pits between its eyes and the nostril. Since a rattlesnake is cold-blooded the sensors are naturally somewhat cool as compared to any warm-blooded prey which improves sensitivity. Probably don't work so well on a hot day.