|
15 minute subs are still comparatively short exposures to what people had to do with film back in the day...
Remember, subs... as in. Sub - exposure... when that wasn't possible, when you wanted to go 3hrs deep, you were literally firing a single 3 hour exposure, with your eye glued to the guide scope eyepiece, manually correcting dec drift.
I would say that for most modest setups, a 60x60x60 block of concrete would be more than sufficient, especially if like Alex, you dug the hole then rammed in a number of star pickets on various angles to bite into the surrounding earth...
Not to say going 1m³ is bad, on the contrary, it's amazing! But unless you've got a 16" scope with a few thousand mm focal length and running 20 minute subs with sub-arc-sec/pixel resolution and the seeing to match, it may be overkill.
Remember, concrete
, if properly composed at time of production, weighs between 2.3 and 2.4 metric tons per m³... that is quite a lot of balast for less than 50kg of mount and scope.
|