There is a very handy camera adapter for bottom loading tape cameras that fits between your camera and tripod head and allows quick tape changes without having to remove the camera from the tripod.
I got one for my Sony A1 and it solved the bottom loading problem.... and they now have adapters for the new Canon HV10 and several other cams that load from the bottom.

Check it out....at

http://www.dm-accessories.com/shop/index.php?main_page=index

Teaktart