IS and night shots

bernard0368

I was taking a few night shots the other night. I had a 28-135 IS USM lens on the camera. I noticed that if the IS was on the pictures were not sharp but when I turned of the IS the shots were sharp. Is this normal or is there somthing wrong with the lens. (The camera was on a tripod)

Paulw

That's normal. If you read the manual, it actually says to turn off IS when mounted on a tripod.

beans

Aye, I noticed the same phenomenon using the Canon 17-85 IS

helios

Think it has to do with the lens's shifting while IS is on....

leohoju

IS/VR/OS whatever flavour you're using expects some sort of movement from the lens and will always try to compensate for this movement. Even if there's no movement it will still try to compensate, hence the need to turn off when mounting on a tripod.

That doesn't seem much clearer does it?

Thirdfox

Unless you have a shaky 5 euro tripod

VR does wonders then

thebaz

is IS / VR mechanically driven or software driven ?

or a mixture ?

Paulw

On Canon/Nikon, it's mechanical (gyros). You can actually hear/feel the motors kick in to stabilise the lens elements.

Thirdfox

@Baz: software "image stablisation" is often just marketing linguo for hi-ISO mode on compact cameras (something to be avoided in almost all cases).

the optical or sensor based image stabilisation is the real deal kind with an actual movement of the lens or sensor to compensate for slight movement.

bernard0368

Thanks, I suppose it does help to read the manuals:rolleyes:

Paulw

A good Canon article on IS - http://web.canon.jp/imaging/lens/technology/index3.html