Originally posted by Adam ...You're right that there haven't been any studies on this, but on the other hand, you don't see reports of failed HSM, and in the consumer world, that's what matters. Even if you do a web search for "Sigma HSM Failure Rate" you don't get anything on the topic.
Adam - just search for Sigma lens failures: Here's some samples
1. Flickr: Discussing The autofocus doesnt work in SIGMA APO 70-200mm f 2.8 EX DG HSM (Macro) (there's 14 complaints altogether on this flickr page regarding Sigma HSM failing, just 2 samples below) Man from the North says:
Sorry to hear that hector. You need to return the lens to the dealer, if it is brand new, demand to get a new lens or your money back.
Same thing happened to me, the autofocus stopped working in my 70-200, just like that. Later on I heard that this seems to be a common problem with Sigmas HSM lenses.
Well, I returned my two year old lens to the camera dealer, and he sent it to a Sigma repair shop. One and a half week later I got it back with a new HSM motor in it, and it is working great. I still had warranty on my lens, so it did not cost me anything
Still, I think itīs pretty bad that the lens just gave up like that, I have not dropped it and I handle all my photo equipment with care.
To add to the misery, I was on a photo trip one thousand kilometers from home when the lens decided to quit on me. :/
kenkyee says:
Could you guys list the first few digits of the serial# when this happens?
I thought Sigma resolved this and it was an issue w/ the early release of this lens (failure was due to HSM rollers sticking)...
2. Flickr: Discussing total lens failure update 3/29/2011 in Sigma 18 ...
Mar 29, 2011 ... Is this lens good for Portrait? ... total lens failure update 3/29/2011 ... I hoped it would qualify for repair/replacement under Sigma's recent ...(included replacement of the hypersonic motor)
3. SLRGEAR.COM Sigma 50-150mm f/2.8 II EX DC HSM APO review by RogerB Review Date: 5/10/2009 Would you recommend the product? No | Total Spent: $700.00| Rating: 3 Pros: sharp lens, good contrast Cons: Poor quality control - lens keeps breaking down My copy of this lens (in Canon fit) was let down by a consistent failure of the autofocus motor in the lens. I had to send it back to Sigma twice to be fixed. And I do not use the lens much. They did fix the lens quickly, but I do not expect 2 failures in such an expensive product. Buyer beware! 4. This from: LensPlay - Lens defects They did a survey of various lens owners. Sigma lenses - 3214 with 725 defects
The probability of getting a good lens is 77 %
The probability of getting 5 good Sigma lenses in a row is 28 %
Pentax lenses - 1753 with 112 defects
The probability of getting a good lens is 94 %
The probability of getting 5 good Pentax lenses in a row is 72 %
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Conclusion:
I think we should enjoy discussing Sigma's new lens without the need to make a derogatory remark in the News comment about SDM focus motors. Without looking very hard, i found the above 16 examples of HSM problems and hadn't expected the survey information from the Lens Rental pages. I'm just saying, Pentax has apparently made some changes to how they assemble the sdm motors and i'm not seeing the number of complaints regarding them, that used to be reported. These lenses and cameras are such complicated mechanisms, that any of them work is amazing. :-)
I'll put my hard hat on :-)