Originally posted by FS1 Not doubting there may be instances of shutter shock with some specific combinations of a 28-105 and a K1. I never expect the old 'reciprocal' rule to apply with a zoom, however. Compared to a 28mm prime, the 28-105 is a relatively long, thin barreled lens... When using zooms, I weigh the longest end (e.g., 105) pretty heavily with regard to 'hand holding' shutter speed expectations.
Funnily enough images are razor sharp 1/25 to like 1/8, Ibis seems to work way better for lower shutter speeds.
My da 50 also displays those issues.
My 15-30 to a much smaller extent, probably due to it being so heavy.