[robgski]

but this 77yr old finds the view through the viewfinder wavers a bit when shooting beyond the 350mm mark!

No shame there. Personally, once I find a comfortable and quick way to carry and employ a tripod while hiking, I try to use it more often to extend my endurance over the course of the hike.
It's not solely age that makes it hard to get a steady aim. Just like marksmanship with a rifle, gaining a steady hold requires both practice, and bit of upper body strength. One need not be Mister Universe, either, but some light weight training, with household objects such as juice cans, milk cartons, flour or sugar bags lifted from waist height to eye level 5 to 10 times will make holding a long lens easier.

[11GTCS]

No shame there. Personally, once I find a comfortable and quick way to carry and employ a tripod while hiking, I try to use it more often to extend my endurance over the course of the hike.
It's not solely age that makes it hard to get a steady aim. Just like marksmanship with a rifle, gaining a steady hold requires both practice, and bit of upper body strength. One need not be Mister Universe, either, but some light weight training, with household objects such as juice cans, milk cartons, flour or sugar bags lifted from waist height to eye level 5 to 10 times will make holding a long lens easier.

That and forearms! My tele macro is actually heavier than my super tele lenses, and doing forearm training has helped a lot with getting steady shots at slower shutter speeds with that baby.