Originally Posted by
Tannin
Contrary to Cage, raised centre columns can be perfectly OK. BUT ONLY where the tripod features a really solid design for the column and a good way to lock it off. My big Manfrotto (forget the model number, but it's a heavy carbon one with 4-part legs and a gear-driven column) is just fine with the column up. Including teleconverters and/or crop factor, I use it with lenses from 600mm through to about 1200mm, mostly between 600 and 840mm. It's not to be trusted over 1200mm (in 35mm equivalent terms) but then, neither is anything else.
But (to agree with Cage now) that's rare. In fact, it's the only one I've ever used that's as solid as that. And the price of the solidity is (a) a very heavy tripod by carbon fibre standards, and (b) quite a lot of money. As he says, best to get one that doesn't need the column up in the first place.