The magnification factor is the ratio between the size of the subject seen on the device screen and its actual size. Said that, on an average smartphone screen the magnification of DIPLE Black is about 150x; it can be multiplied by the digital zoom without observing significant pixelation effect.
A precise calibration of the system (phone+lens) can be performed with a micro-ruler (you can find it among the accessories).
The useful Field of View (FOV) is about 150 micron in diameter, around the center.