I am considering buying a large binocular, 25x100, splitting it in two, and using one as a spotting scope. Selling the other.
Does anybody have an suggestion for a product, to attach it securely to a tripod head?
You can buy a tripod collar, they are made for telephoto lenses. Usually they state the internal diameter, so find one that fits and it should work.
However the question is whether you will save much (or any) money over buying a used 80mm spotter, and also whether the compromises are worth it. Your makeshift scope will not be as sturdy, and optically it will suffer, most obviously in close focus - many spotters will focus to under 10m, a large-aperture binocular may not focus nearer than 20m.
Also at 25x, there will probably not be much advantage for 100mm vs 80mm unless you use it exclusively at dusk/dawn. Under normal daylight conditions an 80mm spotter would be just as good and much lighter.
Remember there is no free lunch - at the same manufacturing cost the spotter will be of far higher quality as the factory only has to buy one set of objectives, one eyepiece, and one focuser.
Edited by Bkoh, 24 July 2021 - 06:28 AM.