I am watching a tutorial on Cam Tracking, but I already met an obstacle in the beginning. I shot a footage, which I want to use for cam tracking, with a Cubot S350, a cheap cell phone from mainland China.
After having distributed the markers on the footage and calculated their tracks, I have to input at least two information about the cam:
- width of the CCD sensor
- focal length
I have searched for a long time, but I found only the sensor width and a couple of other parameters but none of them the focal length. Even on the internet page of the manufacturer inside the specs, there is just a blank space next to focal length.
Is there a way to find it out, do cellphones have a few typical focal lengths I could try, can I calculate the focal length from other given features?