This is a cheap Chinese landvo l200 Android mtk65xx mobile The onlything it keeps Changing is IS0 from 150 to 800 + And exposure time I wondered how can it autofocus and touch Focus when it keeps focal length constant @ 3.5mm. Is that the case with all phones ? Or maybe some high end ones like xperia And HTC have something more in the camera lens
how can it autofocus and touch Focus when it keeps focal length constant @ 3.5mm.
Because focussing is not about changing the focal length. Changing the focal length is called zooming, which your phone-cam doesn't do. Not optically anyway.
Focussing involves changing the distance between (parts of) the lens and the sensor.