If you are far enough away that you can't see what you want to see with 10x, then you will probably need a spotting scope. From 10x to 12x, there isn't really enough difference to justify a new set of binoculars. Anything over that, and you'll nearly needa tripod anyway. The increase in magnification also magnifies wobble, making it hard to hold steady enough to discern the image. And you can get a decent spotting scope at a decent price. I don't know that you can do the same with binoculars. Plus, the binoculars will be 2x as heavy as the spotting scope.