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10-28-2009, 11:59 AM   #1
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Observation on DA* 50-135mm AF/MF operations

Last night, I tried my DA* 50-135mm on my PZ-1p. AF was good and accurate. Then, I mounted it back on my K10D. Once mounted it, I moved AF/MF switch to MF and tried to manual focus. Here's what I noticed: manual focus was very rough (as if an FA lens is still engaged in AF mode). I was afraid of damaging the lens, so I turned it to AF right away and auto-focused it (with SDM of course) several times. Then, did manual focus again. And it was normal again, no rough feeling.

Here are my questions:
1. Has anyone experienced this?
2. Could this be the reason why some DA* owner got their lens's SDM damaged?

Luckily, my 50-135mm is still working fine. I'll never try above focus sequences again. I probably won't even use it on slot-drive only AF camera again.

Last edited by hyyz; 10-28-2009 at 01:44 PM. Reason: syntax
10-28-2009, 12:44 PM   #2
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Can't say that's happened to me. I used my DA 16-50 on my then *ist D with no problems then plonked it back onto my K10D and K20D and both MF and AF worked without hitch.

You're wise in not trying again - it does sound like the screwdrive mechanism was not deactivated once put back onto an SDM-capable body, but I can't think of why.
10-28-2009, 12:47 PM   #3
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I have no experience with the lens, but did you change the switch on the body or the lens (if there is one)?
10-28-2009, 01:17 PM   #4
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Off topic but ... is DA 50-135 FF capable ?

10-28-2009, 01:23 PM   #5
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Heard varying reports, but it's definitely usable at 135mm. Aome people say it's alright down to 80-100mm or so. Expect vignetting,
10-28-2009, 01:43 PM   #6
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Original Poster
QuoteOriginally posted by Eruditass Quote
I have no experience with the lens, but did you change the switch on the body or the lens (if there is one)?
AF/MF switch on the lens. There is such switch on DA* lenses. After that, I even changed the switch on body to MF. It didn't help. Focusing with SDM several times helped though.

I have the feeling that SDM (combined with slot drive) in DA lens is very delicate; the tolerance for mishandling is very narrow.
10-28-2009, 03:24 PM   #7
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QuoteOriginally posted by netuser Quote
Off topic but ... is DA 50-135 FF capable ?
Nope. It's fairly close with the hood removed but there's vignetting through most of the zoom range still. And that is the reason I sold mine and "down-shifted" to the Tamron 70-200/2.8 - I couldn't stand having a beautiful piece of lens that I couldn't use to full effect with my 2 film bodies.

Examples (just some test snaps):

[/end thread hijack]

Last edited by Venturi; 10-28-2009 at 03:31 PM. Reason: example pics

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