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07-11-2008, 08:13 AM   #1
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DA* 50-135 autofocus speed

Ive been using the 50-135 as my walkaround lense for almost 2months now, and I love it! But, last weekend while I was on a little trip I used the 18-55 kitlense to get a wide angle shot, and i was impressed with the autofocus speed on it compared to the 50-135!

Thought the 50-135 should have a faster autofocus than the kitlense (since it has SDM and everything). Am i wrong, or do I have a problem of some sort?
The kitlense has alot shorter way to go from close focus to infinity, could this be the entire reason?

Using a GX10 with firmware 1.3.

07-11-2008, 08:33 AM   #2
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The actual lens travel definitely has an impact on AF speed, but also the fact that SDM is sort of like micro USM which is never known for speed or torque. SDM is quiet and that is it.
07-11-2008, 08:42 AM   #3
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I definitely have other lenses that autofocus faster. However, I find my 50-135 to be much more accurate than others, particularly in low-light.
07-11-2008, 08:49 AM   #4
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Original Poster
Aha, guess i misunderstood the term SDM then! Thanks for the quick replys.

The lense is great, both on manual focus and autofocus. I just thought it was odd how the kitlense seemed so much faster.

07-11-2008, 01:19 PM   #5
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the 50-135 has a longer focal "distance travel" forgot the right word
there's a post on dpreview where someone videotaped the number of frames it took for lenses to go from infinity to zero and back to infinity and iirc, the 50-135 was the slowest
07-12-2008, 07:22 AM   #6
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Yes, when I bought mine I realized it was not as fast as I thought, in fact my DA16-45 is faster and FA35 is fast as hell, comparing with DA*, so I think you shouldn´t worry about that.

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