Jan,
Omitted to say I have fitted Manfrotto quick release kinematics clamps to all the telephoto lenses and have kinematics adjustable clamp bases and have made adjustable base plates on all my telescopes and tracking mounts. They are all pre-aligned and interchangeable. With an eyepiece adapter on the back, thay can be used for acquisition or guiding (with a TV camera). On the small portable mount, one lens balances the other, no counterweights needed.
Chris
