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View Poll Results: What Has Been Your SDM Experience?
DA* 16-50/2.8: No SDM problems 3838.00%
DA* 16-50/2.8: Bad SDM 1313.00%
DA* 200/2.8: No SDM problems 1111.00%
DA* 200/2.8: Bad SDM   00%
DA* 300/4: No SDM problems 1818.00%
DA* 300/4: Bad SDM   00%
DA* 50-135/2.8: No SDM problems 5656.00%
DA* 50-135/2.8: Bad SDM 1010.00%
DA* 55/1.4: No SDM problems 66.00%
DA* 55/1.4/2.8: Bad SDM   00%
DA* 60-250/4: No SDM problems 88.00%
DA* 60-250/4: Bad SDM 11.00%
DA 17-70mm/4: No SDM Problems 1313.00%
DA 17-70mm/4: Bad SDM 22.00%
Multiple Choice Poll. Voters: 100. You may not vote on this poll

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01-05-2010, 10:22 AM   #76
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Well, my focus wasn't locking on my 17-70, and I never voted even though my lens is currently in Pentax's hands for repair. I think a lot of SDM lens owners have not voted due to the simple fact the thread title mostly attracts users who have had problems. If I didn't experience focus problems with my 17-70, I probably wouldn't have taken the time to click on this thread, so I think the numbers may be skewed a bit high.

01-05-2010, 08:22 PM   #77
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My 50-135 on the K10D locks focus quicker than that one in the video. I would say the rotation speed is the same, but it gets closer to an accurate lock with only a little bit of fine tuning.

My FA 50 1.4 is a fair bit quicker due to the screw drive. Same as the 50-135 (and all my lenses) in that it jumps quickly to an "almost lock" and then fine tunes.
01-05-2010, 08:37 PM   #78
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QuoteOriginally posted by PentaxPoke Quote
If I am looking at that correctly, the Canon focused more than twice as fast as the Pentax, using 5-stops less light.

There is no sugar coating that. The Red Herring of "test methodology" doesn't work here. This is a significant weakness in Pentax AF.
One of the advantages that the K7 has over the K20D is better and faster focusing. With that video in mind, anyone who upgrades to the K7 for better focusing is a fool. Wait until Pentax comes out with a real AF system.

Unfortunately Pentax marketing correctly sees the general public's position on this: people who want their SLR camera to take video, not focus quickly...
01-08-2010, 01:44 PM   #79
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QuoteOriginally posted by Russell-Evans Quote
I've seen three posts of this type of failure. When your lens comes back, would you mind replying to this with what was documented as the failure, please?

Thank you
UPS called yesterday to ask if I'd be around today to accept a package. Well, it just arrived from CRIS and they fixed the problem. The documentation says they "replaced HSM (Hyper-Sonic Motor)" and "cleaned and checked to factory specifications".

So it has an entirely new SDM and it locks focus quickly now like it did before I first experienced the problem. I hope this is the end of SDM problems for this lens, as I quite like it.

Maybe we should consider changing the rules for this poll, and allow those who have lenses that wouldn't lock focus to be included in the "Bad SDM" if they had to replace mine.

07-10-2010, 05:02 PM   #80
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Here is my experience, and I started a thread about SDM failure before I found this one. I searched, so this must have been waaayyy down on the search results.

SMC-DA* 16-50 f/2.8
Feburary 2009
Bought New
1st failure was around March of 2010
Repaired/Received back from Pentax 5/1/2010
Out of warranty
Cost to repair was $205 USD
I am now on failure #2 as of 7/9/2010, lens has been shipped to Pentax, and is still under 90 day warranty from last repair.

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