Tech Specs of Built-in iSight Camera of MacBook (13-inch, Aluminum, Late 2008) What are the tech specs of the Built-in iSight Camera of the MacBook (13-inch, Aluminum, Late 2008)?

Especially: What is the focal length?

Does anybody happen to now, if there is something online, where all the technical specifications of my camera are listed?

EDIT: I wrote a program which detects markers of a certain size. After detection I need to calculate the 3D coordinates of those markers, therefore I need the focal length of my camera as this is an input value of the program.
What is recommended is doing a camera calibration yourself, using OpenCV for instance, to get reliable figures.
http://docs.opencv.org/2.4/doc/tutorials/calib3d/camera_calibration/camera_calibration.html

It is not very complicated, just print out the chessboard pattern, tweak the xml file which has input data for information about the test pattern and also the xml for input images(if you plan on using images, instead of live video through your webcam, I recommend the latter) 
Run the sample as it is, following the instructions for keyboard prompts (hold up pattern, press 'g' to start calibration once you see detected lines, esc to exit).