Image Stabilizer on L series lens

[Phoenix]

Hi folks

I've read a few times now that the IS Version of the Canon L series lens can cause problems when focusing on stars and that a non-IS version is better - why is this? Price difference aside, if the IS is a problem then can't it simply be turned off on the lens or is it best to purchase a non-IS lens?

Cheers Steve

[Octane]

There is a switch to turn IS on or off.

The newer lenses have a sensor which detects when the lens is sitting on a tripod and will disable automatically.

But, yeah, just turn it off for great success.

H

[Phoenix]

Thanks for the info Octane. Figured the IS versions would be handy for day time photography but my priority is Astro.

Cheers Steve

[avandonk]

It is really about the 'park' position of the moving bits of optics when the IS is turned off. This is not a problem with my Canon 24 to 105mm F4L.

There are tests around of super telephotos 300mm and 400mm F2.8L both IS that show this problem of a slightly misaligned optical train that also shifts with an astro mounts orientation. The effect is slight 'coma' over the whole field.

Bert

[Phoenix]

Thanks Bert for the extra info. I'll have to do further research. I've had my eye on the canon 24-105mm f/4 L IS or non-IS (so perhaps no issues with the IS version if you and others haven't experienced problems), the 70-200mm f/4L (IS or non-IS) or alternatively the 70-300mm f/4L (IS or non-IS). I here the 70-200mm is a great astro performer for a zoom.

Cheers
Steve

[Octane]

The 24-105mm f/4L IS USM is not available in a non-IS variant. :)

I love mine; despite it lacking microcontrast (meh, and, stuff) it makes for a spectacular portrait lens. Mine is one of the sharpest tools in the shed.

H

[Phoenix]

Oops - thanks Octane, I should have known this. Cheers