Pentax-F 1.7x AF Adapter focus adjustment on K-5

oeriies · 03-24-2013, 02:46 PM

I've been playing around with the 1.7x AF Adapter on a DA* 300mm mounted on a K-5 in the hope that it would be a workable long telephoto for an upcoming trip for which taking my Sigma 500mm isn't practical. The image quality is acceptable. My problem is that the adapter/lens combo back focuses when using it through the view finder. Interestingly, it is is spot on with live view. I want to get it to focus correctly when using the viewfinder. The AF fine adjustment through the K-5 menu doesn't pick up a lens ID so the only option is to dial in an adjustment value that will apply to all lenses. That will screw up autofocus on every other lens unless I can remember to reset the fine adjustment setting every time I mount and dismount the 1.7x adapter. Is there another solution I've overlooked? An adjustment to the adapter itself? A way to fool the K-5 into giving the adapter a unique ID?

Russ

Adam · 03-24-2013, 03:52 PM

I don't think there's any other alternative, unfortunately.

vonBaloney · 03-24-2013, 04:05 PM

If you aren't using any other AF adjustment, then turning on/off the whole adjustment system only involves one menu change (it should save what you dialed in for when you turn it back on). Not ideal, but how often are you going to take that thing on and off?

**Kerrowdown** · 03-24-2013, 04:27 PM

Originally posted by oeriies

reset the fine adjustment setting every time I mount and dismount the 1.7x adapter

I can see that becoming very quickly one big pain in the a***.

vonBaloney · 03-24-2013, 05:10 PM

Any chance AF adjustments are saved in the USER modes?

oeriies · 03-24-2013, 05:13 PM

Originally posted by Adam

I don't think there's any other alternative, unfortunately.

That's what I thought but I reckoned it was worth asking. Thanks for the info.

03-24-2013, 02:46 PM	#1
oeriies Inactive Account Join Date: Mar 2011 Posts: 121	Pentax-F 1.7x AF Adapter focus adjustment on K-5 I've been playing around with the 1.7x AF Adapter on a DA* 300mm mounted on a K-5 in the hope that it would be a workable long telephoto for an upcoming trip for which taking my Sigma 500mm isn't practical. The image quality is acceptable. My problem is that the adapter/lens combo back focuses when using it through the view finder. Interestingly, it is is spot on with live view. I want to get it to focus correctly when using the viewfinder. The AF fine adjustment through the K-5 menu doesn't pick up a lens ID so the only option is to dial in an adjustment value that will apply to all lenses. That will screw up autofocus on every other lens unless I can remember to reset the fine adjustment setting every time I mount and dismount the 1.7x adapter. Is there another solution I've overlooked? An adjustment to the adapter itself? A way to fool the K-5 into giving the adapter a unique ID? Russ

03-24-2013, 03:52 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	I don't think there's any other alternative, unfortunately. 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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03-24-2013, 04:05 PM	#3
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	If you aren't using any other AF adjustment, then turning on/off the whole adjustment system only involves one menu change (it should save what you dialed in for when you turn it back on). Not ideal, but how often are you going to take that thing on and off?

03-24-2013, 04:27 PM	#4
Kerrowdown PEG Moderator Join Date: Aug 2008 Location: Highlands of Scotland... "Hold Infinity in the palm of your hand" - William Blake Photos: Gallery Posts: 57,816	Originally posted by oeriies reset the fine adjustment setting every time I mount and dismount the 1.7x adapter I can see that becoming very quickly one big pain in the a***.

03-24-2013, 05:10 PM	#5
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Any chance AF adjustments are saved in the USER modes?

03-24-2013, 05:13 PM	#6
oeriies Inactive Account Join Date: Mar 2011 Posts: 121 Original Poster	Originally posted by Adam I don't think there's any other alternative, unfortunately. That's what I thought but I reckoned it was worth asking. Thanks for the info.

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