RA Indicator - EQ3-2
A potentially useful means of calibrating the mount's motion in RA. Once top dead centre has been established, imaging either through (equal exposure before and after) TDC (or BTC) stands the best chance of minimising poor image quality due to periodic error. For the EQ3-2, each degree of the slow motion drive equates to approx 1.8 secs in terms of transit time. Unfortunately you could be waiting 4 minutes+ between shots.