16-50mm DA* decentering?

keos · 08-06-2018, 07:47 PM

is there just bad QC on these lenses? I'm testing one at 2.8 and the center sharpness is not very good, but slightly offcenter and the sharpness is amazing. Seems like a decentered lens?

Adam · 08-06-2018, 08:09 PM

Originally posted by keos

is there just bad QC on these lenses? I'm testing one at 2.8 and the center sharpness is not very good, but slightly offcenter and the sharpness is amazing. Seems like a decentered lens?

Could be decentering, could be the lens is in need of AF adjustments, could be the scene was improperly focused. Only a methodical test will reveal this:

How to Check Your Lens for Decentering - Articles and Tips | PentaxForums.com

While AF failure is the only major QC issue with this lens, it's certainly possible that there's something wrong with your copy. The warranty would cover this.

If it's just a question of AF adjustments, those can usually be handled via the in-camera setting.

keos · 08-06-2018, 08:14 PM

Originally posted by Adam

Could be decentering, could be the lens is in need of AF adjustments, could be the scene was improperly focused. Only a methodical test will reveal this:

How to Check Your Lens for Decentering - Articles and Tips | PentaxForums.com

While AF failure is the only major QC issue with this lens, it's certainly possible that there's something wrong with your copy. The warranty would cover this.

If it's just a question of AF adjustments, those can usually be handled via the in-camera setting.

forgot to mention, I'm testing in live view, so focus settings wouldn't help me anyway.

Adam · 08-06-2018, 08:25 PM

Originally posted by keos

forgot to mention, I'm testing in live view, so focus settings wouldn't help me anyway.

AF fine adjustments wouldn't, but if you are using AF, it's still possible for the camera to focus on something other than intended. Manual focus is a must for this kind of testing, if you aren't using it already.

Adam
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Kozlok · 08-07-2018, 04:02 AM

Post an example?

08-06-2018, 07:47 PM	#1
keos Senior Member Join Date: Jan 2018 Posts: 108	*16-50mm DA decentering?** is there just bad QC on these lenses? I'm testing one at 2.8 and the center sharpness is not very good, but slightly offcenter and the sharpness is amazing. Seems like a decentered lens?

08-06-2018, 08:09 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by keos is there just bad QC on these lenses? I'm testing one at 2.8 and the center sharpness is not very good, but slightly offcenter and the sharpness is amazing. Seems like a decentered lens? Could be decentering, could be the lens is in need of AF adjustments, could be the scene was improperly focused. Only a methodical test will reveal this: How to Check Your Lens for Decentering - Articles and Tips \| PentaxForums.com While AF failure is the only major QC issue with this lens, it's certainly possible that there's something wrong with your copy. The warranty would cover this. If it's just a question of AF adjustments, those can usually be handled via the in-camera setting. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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08-06-2018, 08:14 PM	#3
keos Senior Member Join Date: Jan 2018 Posts: 108 Original Poster	Originally posted by Adam Could be decentering, could be the lens is in need of AF adjustments, could be the scene was improperly focused. Only a methodical test will reveal this: How to Check Your Lens for Decentering - Articles and Tips \| PentaxForums.com While AF failure is the only major QC issue with this lens, it's certainly possible that there's something wrong with your copy. The warranty would cover this. If it's just a question of AF adjustments, those can usually be handled via the in-camera setting. forgot to mention, I'm testing in live view, so focus settings wouldn't help me anyway.

08-06-2018, 08:25 PM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by keos forgot to mention, I'm testing in live view, so focus settings wouldn't help me anyway. AF fine adjustments wouldn't, but if you are using AF, it's still possible for the camera to focus on something other than intended. Manual focus is a must for this kind of testing, if you aren't using it already. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

08-07-2018, 04:02 AM	#5
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	Post an example?

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