should I turn off OIS, at maximum telephoto, if my A1 is on a tripod?
thanks!

if u intend on panning then yes.. however if the A1 OIS is anything like the XL2, then youd still be safe as IMO the XL2 is king OF OIS. Its "floaty" therefore it doesnt jarr or try to "obviously" compensate when panning

Depends on how sturdy and stable the tripod is, and perhaps a bit as to what you are shooting. With a very good tripod on a stable base you probably will do somewhat better with it off. Let your review of your tapes be your guide.

I haven't tested with the OIS off, but I can vouch for the footage being a bit shakey when the OIS is on (and mounted on a tripod at max zoom). I'm definitely thinking I need to try the IS on the OFF position.

Also, I didn't notice the shake when I was shooting, but it's sure apparent on my TV/projector.

0) DaM

off.

..and if you will be on a tripod a lot, get the lanc remote.

exceptions of leaving the OIS on during tripod shoots would include
major wind, earthquakes, and any event or party with that "slammin'" guido bass.

So is it best to leave it off most of the time?

If "most of the time" is nice and steady with no problematic vinbration. You have to understand the capabilities and limits of using OIS, and judge your specific shooting environment/circumstances at the time, and set OIS accordingly. On the average - OIS off when shooting from a tripod, but there are plenty of exceptions to the "average."

I side with Don here. There is no universal truth. If you leave it off, you will see vibrations if your equipment and/or your technique are not significantly above average. If you turn it on, you are likely to see the picture "stick" a bit when you start panning. Both phenomenon are quite noticeable in the viewfinder or the LCD panel; experiment for yourself and pick the best compromise to fit your shooting conditions. If you have time, making a test recording using both settings and then reviewing the tape is even better.

In my case, using a Bogen / Manfrotto 503 head with a 523 LANC controller, I have gone back-and-forth as I have experienced both limitations.