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10-02-2013, 09:21 AM   #1
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Anyone else have SEVERE back-focus with 40mm XS?

Works great on my Q, but on my K-x it's unusable. Severe back-focus. So much that I cannot adjust it out completely with the debug menu (and that's such a hassle anyhow).

Bought the kit with the 40mm XS so I could use that lens on my K-x too, but that's not possible now.

May have to upgrade to a K30 :/

Charles.

10-02-2013, 09:25 AM   #2
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Er, if you don't have other lenses that have as much focus adjustment, then upgrading to a k-30 won't really solve your backfocus issues... you should look into sending the DA 40mm XS back for warranty fix.
10-02-2013, 09:41 AM   #3
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Nope, the only other lens I have that has front/back focus issues is the Tamron 28-75, and that's pretty mild in comparison.

Doesn't the K30 have adjustments for multiple lenses?

XS is probably out of warranty by now, and it does work perfect on the K-01...

Charles.
10-02-2013, 09:59 AM   #4
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It does, but I think it's limited to +/-100 micrometers. Not so sure. I know my k-x can go to something like +/-200 micrometers, so if that adjustment doesn't work, the k-30 won't really help you there.

Not to mention, if it's that far off, there is likely an optical issue in the lens.

10-02-2013, 11:12 AM   #5
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Anyone in the Durham, NC area and want to try out a 40mm XS on their camera? To see if adjustment is possible, and take some shots if you like?

Or tell me that nothing is wrong with it and I'm imagining things?

Charles.
10-02-2013, 11:21 AM   #6
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I have pretty severe back-focus with my DA* 300mm lens. I have to use all available in-camera adjustment to get it right.

Living in Panama presents numerous challenges, one of which is an effective inability to return/replace things like this (I tend to order things on the web and have them shipped to various friends and relatives in the U.S. for collection when I visit--I never have time to return things like this so, unless it's completely unusable I'll make do).

Some small and/or inexpensive things I can ship direct to Panama, but I was surprised to find that focusingscreen.com doesn't include Panama as a valid shipping destination... So far they haven't responded to my e-mail...
10-02-2013, 12:03 PM   #7
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QuoteOriginally posted by ChopperCharles Quote
Works great on my Q, but on my K-x it's unusable. Severe back-focus. So much that I cannot adjust it out completely with the debug menu (and that's such a hassle anyhow).

Bought the kit with the 40mm XS so I could use that lens on my K-x too, but that's not possible now.
When I've used the DA 40 XS on my K-x,
it's mainly been for "stealth" shots,
so I've used CDAF in Live View.
Pretty much nails it.
10-22-2013, 09:30 AM   #8
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So strangely, the 40mm XS has no back-focus problems on my new K-30. It's spot-on every time.

Charles.

10-22-2013, 10:08 AM   #9
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My 40mm XS needs +120 on my K-x. It seems to be a issue with the K-x focusing system shooting apertures larger than f/3.5. I made the adjustment using the debug mode to get it right. What's weird is my kit lense are spot on. The DA 35 f/2.4 is -100 adjustment.
10-22-2013, 11:06 AM   #10
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My 50mm f1.7 is perfectly accurate on my K-x, so it's not all lenses with large apertures.

Charles.
10-23-2013, 10:12 PM   #11
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QuoteOriginally posted by ChopperCharles Quote
My 50mm f1.7 is perfectly accurate on my K-x, so it's not all lenses with large apertures.
Are you refering to a manual lens? M? My M 28mm f/2.8 and A 50mm f/1.7 work real well on the K-x, but I'm taking time to get it right. The focus confirmation gives me a large area of focus confirmation when using manual lenses.
My 50mm f/1.8 is close to spot on.
Btw, Live View seems to be always spot-on. With the 40mm XS or 35mm f/2.4, they seem to be spot on at all apertures. The speed on the K-x just kills me in Live View.
10-24-2013, 07:10 AM   #12
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Nope, FA50 f1.7. I wouldn't be talking about AF with a manual lens.

Charles.
10-24-2013, 07:27 AM   #13
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Not sure if this will be of any help but it seems that I am among the luckiest one - my K10D has permanent setting +170 um and that works for ALL my AF lenses- every single one is always focusing right there - both primes and the zooms - and XS 40mm is one of three primes I have, the other one F50mm 1.7 and F28 2.8 - all works perfectly. I spent quite a lot of time and about 200 shots to get it right. My advice is try to go through the process and calibrate the camera for this specific lens again - but pay attention to the details and also make sure you use reliable conditions - the distance, light and the target should remain the same for all the shots. of course tripod is a must. After that you might be able to see if perhaps this specific lens requires some sort of *specific* setting - that would mess up all the other lense. Note: K10D has only one global setting to adjust the AF - not sure about your camera.

--manntax
10-24-2013, 07:46 AM   #14
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QuoteOriginally posted by ChopperCharles Quote
Nope, FA50 f1.7. I wouldn't be talking about AF with a manual lens.

Charles.
Sorry, thought you might be talking about the auto focus indicator with manual lens. My mistake...
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