On Aug 13, 12:25 am, RPS wrote:
What is the maximum telephoto length you would be comfortable shooting
handheld, with IS as well as steadying your arm with elbow on a railing
etc, but no tripod? Thanks.

One quick rule of thumb is about the reciprocal of the exposure time.
Now, I find this optimistic- I'd really recommend about half that.
But as the rule of thumb goes, if you can shoot at 1:500 second you
can hand-hold out to 500 mm. As I say, I'd really recommend 250
myself.

As the allowable exposure time increases, you need to reduce the focal
length accordingly.

This value was for 35mm film, so the focal length used is the "35mm
equivalent".