[Andrew C]

Having received advice from this forum recently about the value of drift alignment for longer videocam exposures (amongst other purposes), I am now practising same. But I am puzzled as to how long one should check for.

Many comment on the web that checking after the (final) drift alignment for no drift over a 5 or 10 minute minute period is sufficient to ensure no drift during a photographic session over 2 or 3 hours. This doesn't compute for me unless people are using some form of guiding in conjunction with the photographic exposure and are assuming but not stating that guiding is always going to be necessary.

For live videocamera viewing, surely I would need to get the drift down near enough to zero for the periods I am typically exposing for, since there is no guiding involved.

Or am I missing something?