Hi psadams
15x70s (not "50x70" Eeeek!) would go very nicely on a tripod. I cannot say much about that particular tripod but your problems (in my limited experience) can be:-
1) Too heavy for the tripod - risk of overbalancing, particularly if bumped. Note that these binoculars don't come with a central mounting bar, so you will be using a binocular mount (check they come with one - try for metal, not plastic - I think AOE supply a good metal one with them or for a few more $s). This does mean that when you tilt the binoculars upwards, the centre of gravity can move a fair way out from the centre of the tripod.
2) Difficulty in getting your legs under the legs of the tripod (depending on the radial brace arms?). I find I prefer to sit (check small plastic stools - even upside down plastic rubbish bins!), but you need to be able to get your lesgs in under the tripod without your knees touching legs or radial brace arms.
3) Response to wind - 15x should not be too bad, but if the tripod gets a real jiggle up, your image bounces all over the place. Hard to check except "in the field" - but you may be able to set up at a camera store looking across the street with the binoculars, then tap the tripod and see what happens (and for how long it happens). Yes, some hang sandbags and bricks off the radial supports but think of the total weight - major structural collapse might be coming! I'm also sure that winding up the elevator only increases the problem. I try to keep the elevator fully lowered - then you have to be able to move your seat up and down (I use gas lift. try a piano stool?)
4) "Binocular neck" - the problem of getting to any altitude in the sky. In no time, you get all tangled up in the tripod trying to get your head positioned to look through the eyepieces. Again, you need to try any particular tripod.
5) Which leads me to the pan-handle arm. On some tripods, you end up having to swallow the first half of it to get your eyes on the binoculars. Try to find one that has a short arm or it bends down or is well below the plate.
6) If you do plan to multi-use the tripod, one with a quick release plate is recommended. Buy a few extra plates so you can dedicate one plate to each item you wish to put on the tripod.
My experience is that a set of 12x60s (AOE) have worked a treat on a Velbon CX-540. I have even used a set of 20x80s (with a central support bar) on the same tripod (with care - it is overloaded at that stage!).
I recently bought someone else a Velbon CX-560 for a set of 20x80s with a central support bar. It was $100, but I was impressed - I'd have bought the CX-560 for myself if I'd seen it before I bought the CX-540. The CX-540 has a support plate which basically connects only one side so it "hangs" in space(check some pics here:-
http://www.velbon-tripod.com/cx.htm ). I jamb a piece of wood under it in some situations. The CX560 panhead rotates down to sit solidly supported on both sides.
Ted's Camera Stores supposedly have a Velbon CX-586 on special for $110. It's designed for video cameras - it looks like it might be a good option.
Sorry, I cannot advise on the tripod you are looking, but I suggest that you need to get "hands-on" with tripods at the camera store - with the binoculars, if possible. So many things become clear later, otherwise!
Good luck and happy viewing!
