Sigma 150mm macro lens

Marcus7100 · Sep 28, 2015

Hello everyone
I'm new to the forum and would like to apologize in advance if I happen to be posting in the wrong place.

So I'll begin by saying that I've been into photography for about 3 years now and I'm using a Nikon D7100.
Recently I have been using a Sigma 150mm f/2.8 macro lens (with OS). It's a great lens by the way, only this evening (I live in Sri Lanka btw) I noticed that the lens element(s) start rattling by itself when the camera is switched off. Also, the elements start 'jumping' when I use the lens with OS turned on.
I'm not sure why it's behaving this way...
I'd really appreciate any insight and advice (and some possible explanation).
Thank you

Overread · Sep 28, 2015

The OS, like most anti-shake works by moving a section of elements within the lens around, this motion then works to help counter handshake motion, however to work the lens has to "spin up" ergo it has to get the elements moving, detect the motion and then adjust to counter it*. This means that you can often see a little motion when you first half press the shutter and the lens "wakes up" causing the OS to engage and the AF to engage also (if active of course).

However when disabled the elements should not continue to move and the "jump" should only be minor and only at the very start (its normally more noticeable if you turned the camera off or removed the lens whilst the OS is running and thus hasn't completed its "spin down" cycle).

At best you might be turning the camera off/removing the lens before the whirring sound of the OS elements moving has stopped; at worst it might mean that something inside is lose on the OS system; this might not show up in photos since the back/forward direction of the elements hasn't changed, so it won't get softer, but the side to side is a problem.

If would try testing it with the on-off theory above and if that fails it sounds like its an issue for sending it back for repair - if its new warranty should hopefully cover it.

*in some it also turns off if it detects no shake

Marcus7100 · Sep 28, 2015

Overread said:
The OS, like most anti-shake works by moving a section of elements within the lens around, this motion then works to help counter handshake motion, however to work the lens has to "spin up" ergo it has to get the elements moving, detect the motion and then adjust to counter it*. This means that you can often see a little motion when you first half press the shutter and the lens "wakes up" causing the OS to engage and the AF to engage also (if active of course).

However when disabled the elements should not continue to move and the "jump" should only be minor and only at the very start (its normally more noticeable if you turned the camera off or removed the lens whilst the OS is running and thus hasn't completed its "spin down" cycle).

At best you might be turning the camera off/removing the lens before the whirring sound of the OS elements moving has stopped; at worst it might mean that something inside is lose on the OS system; this might not show up in photos since the back/forward direction of the elements hasn't changed, so it won't get softer, but the side to side is a problem.

If would try testing it with the on-off theory above and if that fails it sounds like its an issue for sending it back for repair - if its new warranty should hopefully cover it.

*in some it also turns off if it detects no shake

Thank you for the input. I was starting to think about it, only none of my Nikon VR lenses behave that way. Anyways, it makes sense and I've read that Sigma's OS is different from the Canon/Nikon systems.
I'll try it out with the on/off and see how it turns out.