charding exactly! Between each exposure, it on whatever schedule you set (maybe every third exposure) forget the scope without a guide camera. To go a step further, for this that have fast scopes (mine is an f/2 because of a Hyperstar) then you could consider using the main scope as a guide scope too. Pick a guide star, take a 30 second light, use it to see if it is tracking correctly, make an adjustment, check again, make any additional adjustments, then take the next 30 second light. Rinse and repeat.