# Sigma and Tamron OS/VC quirks



## 3kramd5 (Aug 22, 2014)

I now own two third party stabilized lenses, the sigma 70-200 2.8 EX (there are a lot of letters and I always forget them) and the tamron 150-600. I've noticed a quirk they both exhibit that none of my canon IS lenses do: when the stabilizer engages, the frame tilts down what visually feels like about 5-10°. With the 70-200, it's not that bad, but at 600mm with the tamron, 10° is a lot. 

Has anyone else noticed that kind of this happening? What's the explanation? Misalignment in the stabilizing optic? Maybe I'll shoot a video if nobody can picture what I'm seeing.


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## weixing (Aug 22, 2014)

Hi,


3kramd5 said:


> I now own two third party stabilized lenses, the sigma 70-200 2.8 EX (there are a lot of letters and I always forget them) and the tamron 150-600. I've noticed a quirk they both exhibit that none of my canon IS lenses do: when the stabilizer engages, the frame tilts down what visually feels like about 5-10°. With the 70-200, it's not that bad, but at 600mm with the tamron, 10° is a lot.
> 
> Has anyone else noticed that kind of this happening? What's the explanation? Misalignment in the stabilizing optic? Maybe I'll shoot a video if nobody can picture what I'm seeing.


 My tamron 150-600mm will usually just "jump" (meaning that it'll return to the initially aiming point) a bit when IS is activated... sometime if the IS is not activated for a long time, the frame will move down a bit, but still very close to my AF point... at 600mm, the distance it move is around the size of my 6D centre AF point... not very much... my handshake is easily 10 times worst than that... ha ha ha  

Have a nice day.

Have a nice day.


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## AlanF (Aug 22, 2014)

My 150-600 doesn't have that problem or indeed any that others have reported. My former 100-400L used to drift in IS.


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## 3kramd5 (Aug 22, 2014)

weixing said:



> Hi,
> 
> 
> 3kramd5 said:
> ...



Haha, yah hand shake is much worse. It's easy to compensate for, but it just seemed... quirky.



AlanF said:


> My 150-600 doesn't have that problem or indeed any that others have reported. My former 100-400L used to drift in IS.



Interesting. Maybe it's just a manufacturing tolerance issue if yours doesn't do it.


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