Over the years, I've noticed about three slightly different methods and each is useful in particular situations.
1.?ÿ I'll refer to as the Karoly as Dave has already explained it in detail.
2.?ÿ Essentially the same as 1, but set one leg first and then use the other two and the optical/laser plummet to get over the point.?ÿ Set the remaining two legs and adjust only those two legs to get the bulls eye very closely centered.?ÿ Fine tune with the screws.?ÿ Shift tribrach as needed (should be slight) and then use the screws to level again.?ÿ Check/shift/relevel as needed, but shouldn't be more than twice with practice and if everything is in adjustment.
3.?ÿ Same as 1 above, but instead of relying on eyeballing being nearly over the point, use a plumb bob to make sure before setting the legs.
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1 is my preference and works most times.?ÿ 2 can be useful if your just having one of those days where you keep missing the alignment over the point by eye.?ÿ 3 can be very helpful on significant slopes or with the fixed leg tripod Larry Best mentioned.
I had an IM with a super power. He would spread the legs around the point. Horizon level the head over the point, stamp in the feet. Screw on the instrument, level it and do a slight adjustment to it.
He never had to swing any legs, never had to get over the point. He only had to place the tripod up and the head was centered and plumb over the point.?ÿ I never saw anyone else that could do it, I sure can't.?ÿ
My boss does this. The trick it to visually bisect the point with 2 legs to start, with the last leg swing it until it visually bisects the 2 you just set. It works but you will be using the heck out of your tribrac screws.I hate using the "gun" after him because everything is a quarter turn from maxed out.?ÿ