Image Stabilisers - When to use ?

[philperry]

What does everyone recommend when using a long telephoto (e.g. 400mm + 1.4x) resting on a bean bag. Is it best to keep the lens' image stabiliser switched on or off ? Does it make a difference ? I normally press my lens down into the bean bag and am not sure which IS technique I should be using.

[Roger Clark]

Phil,
I think it depends on the lens and the generation of the image stabilization. I assume Canon since you are saying IS. What 400 mm lens? On the type 1 IS, I would turn it off under three circumstances: shutter speed above about 1/1,000 second, when stable as on a tripod, and long exposure times on a tripod, about 1/10 second or longer. A beanbag can be quite stable too so you might not need IS for shutter speeds above about 1/300 sec. If newer IS, I leave it on most of the time, except for very long exposure times on a tripod (longer than about 1/10 second). At higher magnifications, above about 500mm, small vibrations occur on tripods and beanbags so IS helps, especially in the 1/10 to 1/500 second range, at least in my experience.

[philperry]

Thanks Roger, that is very useful

I am using a Canon EF 400mm f4 DO IS with a 1.4x

[Roger Clark]

Phil,
As that is a newer lens design, it probably has the newer IS system. If you can confirm that, then it will work well pretty much all the time, except very slow shutter speeds.

[philperry]

Thanks Roger. It is one of the most recent Canon lens designs. So I think I will carry on using the IS. I just need to keep working on my technique to get more reliable critical sharpness. I think that now and again I lose sharpness by stabbing at the shutter release button - I need to keep the action smoother. At least I need not worry that the IS is introducing any blur.

[jpons]

Roger is correct, and the 400 DO DOES have the IS version that will detect when on a tripod or other stationary object, so I would most definitely keep the IS on.

I shoot from a beanbag with my 500/4 very often and always have the IS on.

-J

[philperry]

Thanks Juan. That's very reassuring. It is so easy these days to make a small mistake in technique that loses that 'would have been' photo.