In article <46jamr$pkb@navajo.gate.net>, eml@news.gate.net
says...
(Much Deleted)
>I read an article a lot of years ago regarding shake and telephoto
>lenses, and there were several people quoted who were proponents
>of NEVER putting the camera/lens on a tripod, regardless of how
>sturdy it was. Their attitude was that the best results were
>obtained by hand or shoulder-stock holding the camera while resting
>the camera on a beanbag or sandbag.

Years ago, when I first tried a Nikkor 500mm mirror, I tried HARD
to get a sharp image using a good, heavy tripod, and consistently failed. Years later, I tried another 500mm Nikkor mirror, but this
time I took it out on a nice, bright day with Tri-X hand-held - and
got lots of sharp pictures. The viewfinder image looked terrible - shaking and unsharp - but the negatives looked great. I learned something: I may shake with this short, light lens, but if the shake rate is enough slower than the shutter speed, I can get sharp pictures. (I have since learned to not extend the legs of the tripod when using one with a mirror lens, and to weigh down the whole rig with a jacket, camera bag, or hand during exposure.) I still get good results with the 500mm Nikkor mirror hand-held, even with the TC14B converter - though sometimes I use it with a gunstock, sometimes with a gyro-stabilizer
to slow the rate of that shaking.
Hope this helps.