Any tips for easy focus calibration on E1 – iZugar Edition?

Since the image is highly compressed onto a circle, you may want to zoom in for seeing the details when watching through the small display on the back. Simply set the camera to 1:1 mode (like 1920*1920 or 2432*2432) and use the MF assist mode, you can zoom into the center portion. by checking some calibration chart or something with high contrast you can calibrate your lens much easier.

Or, it you get access to some nice external display which can zoom 100% and with peaking function, the job could be done much faster.