Confused about a Sigma lens for Pentax

November 2, 2009 9:44 PM

This new lens from Sigma (18-250 zoom) comes in a Pentax mount. Pentax puts their DSLR image stabilization in the camera body and not in the lens like Nikon or Canon. Yet the description for all the lenses is the same - image stabilization in the lens. Is this a case of cut&paste product descriptions or would using this lens on a Pentax camera have double image stabilization (both lens & camera body)?

The Amazon description seems to indicate it's in the lens but the English is a bit wonky. I'm also curious whether this lens is worth the higher price versus the similar Pentax & Tamron lenses.

posted by GuyZero to shopping (5 comments total)

That lens does have image stabilization (IS).
I don't think you'd want both optical stabilization (lens) plus sensor stabilization (cam). Getting the two to work together could be a real challenge by what I've read. (would they cancel each other? or worse, cause blurred images repeatedly?)

So, it seems questionable why you would want to pay the extra money for an IS lens if the cam already has IS.
However, since sometimes lens IS is better than camera IS (i.e., long telephoto lens), it may be possible to turn off the camera's IS to take advantage of the lens technology.

Not definitive answers or using your camera/lens, but there is more at here under "What's next?".
And, here.
posted by artdrectr at 11:07 PM on November 2

As a new micro four thirds mount user, I've read about an olympus body with IS and a panasonic lens with IS and everyone agrees that the two do not work together, that you need to pick one or the other. Since in lens IS is often better than in body IS (or so I've read at dpreview, fred miranda, etc.) you'd turn off your in body IS when using this lens.
posted by Brian Puccio at 2:56 AM on November 3

Haven't ever tried this, so I'm speaking purely from theory, but...

As an engineer, I have never seen a situation in which two competing control systems are anything you would want. They wouldn't cooperate, they wouldn't enhance or act in a gestalt manner, and they wouldn't take turns. They would probably fight, oscillate, or run away (like the squeal from feedback in a microphone too close to the speakers).

So, no advantage, and you'd want to turn one system off.
posted by IAmBroom at 5:06 AM on November 3

There are many Pentax cameras without in-body IS, that's why Sigma offers such a lens.
posted by jedrek at 5:37 AM on November 3 [1 favorite]

Pentax hasn't made a camera without in-body stabilization in several years. I think the reason this lens has built-in IS is that it is cheaper to build the same lens for every mount, rather than a separate manufacturing line for Pentax lenses. This way, the only thing they have to build differently is the mount.
posted by Quonab at 2:15 PM on November 3