Another (different) K-5 Shake Reduction query

kypfer · 07-11-2018, 11:30 AM

I have a Sigma EX 70-200mm f/2.8 which my K-5 is perfectly happy with, but what occurred to me was :

"Does the camera 'know' when the matching 2x adaptor is fitted or does it still treat the assembly as a 70-200 (instead of a 140-400 f/5.6) when Shake Reduction is activated?"

I'm not aware of any issues that I might attribute to this situation, but it'd be good to know if something crops up at some point.

Thanks for any knowledgeable responses

Adam · 07-11-2018, 11:44 AM - **1 Like**

Originally posted by kypfer

I have a Sigma EX 70-200mm f/2.8 which my K-5 is perfectly happy with, but what occurred to me was :

"Does the camera 'know' when the matching 2x adaptor is fitted or does it still treat the assembly as a 70-200 (instead of a 140-400 f/5.6) when Shake Reduction is activated?"

I'm not aware of any issues that I might attribute to this situation, but it'd be good to know if something crops up at some point.

Thanks for any knowledgeable responses

I know it does with the Pentax DA 1.4x TC. With your Sigma TC, if the focal length in the EXIF shows up as being doubled, then the answer to your question is "yes". Otherwise no, and the SR performance would be a little bit less than optimal.

kypfer · 07-11-2018, 11:18 PM

Thanks for the detailed information. I've now checked my lens/camera combinations and confirmed that my K-5 doesn't appear to recognise that this 2x adaptor is fitted, though it does 'know' what focal length the lens is set to.

**mikesbike** · 07-11-2018, 11:51 PM

i would assume you could input a different FL of the lens to optimize SR function? I've not tried such myself.

kypfer · 07-12-2018, 02:28 PM

Originally posted by mikesbike

i would assume you could input a different FL of the lens to optimize SR function? I've not tried such myself.

Sorry, not quite sure what you're suggesting. On my camera, if the lens is recognised, as this particular Sigma is, there's no opportunity (that I am aware of) to change the focal length. It's only with older manual-focus lenses that I'm offered the option to enter the focal length of the lens, the option on the menu is "greyed out" when a recognised lens is fitted.

07-11-2018, 11:30 AM	#1
kypfer Pentaxian Join Date: Jan 2018 Location: Jersey C.I. Posts: 3,593	Another (different) K-5 Shake Reduction query I have a Sigma EX 70-200mm f/2.8 which my K-5 is perfectly happy with, but what occurred to me was : "Does the camera 'know' when the matching 2x adaptor is fitted or does it still treat the assembly as a 70-200 (instead of a 140-400 f/5.6) when Shake Reduction is activated?" I'm not aware of any issues that I might attribute to this situation, but it'd be good to know if something crops up at some point. Thanks for any knowledgeable responses

07-11-2018, 11:44 AM - 1 Like	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by kypfer I have a Sigma EX 70-200mm f/2.8 which my K-5 is perfectly happy with, but what occurred to me was : "Does the camera 'know' when the matching 2x adaptor is fitted or does it still treat the assembly as a 70-200 (instead of a 140-400 f/5.6) when Shake Reduction is activated?" I'm not aware of any issues that I might attribute to this situation, but it'd be good to know if something crops up at some point. Thanks for any knowledgeable responses I know it does with the Pentax DA 1.4x TC. With your Sigma TC, if the focal length in the EXIF shows up as being doubled, then the answer to your question is "yes". Otherwise no, and the SR performance would be a little bit less than optimal. 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:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
K-5 Shake Reduction query	kypfer	Pentax DSLR Discussion	10	07-09-2018 08:42 AM
k 50 shake reduction shake	jacques	Visitors' Center	6	10-17-2017 11:07 AM
K5 II video shake mechanical or electronic shake reduction?	Rice	Pentax K-5 & K-5 II	3	06-14-2014 02:51 PM
another shake reduction post....	AK_shooter22	Pentax DSLR Discussion	21	02-10-2009 12:46 AM

07-11-2018, 11:18 PM	#3
kypfer Pentaxian Join Date: Jan 2018 Location: Jersey C.I. Posts: 3,593 Original Poster	Thanks for the detailed information. I've now checked my lens/camera combinations and confirmed that my K-5 doesn't appear to recognise that this 2x adaptor is fitted, though it does 'know' what focal length the lens is set to.

07-11-2018, 11:51 PM	#4
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	i would assume you could input a different FL of the lens to optimize SR function? I've not tried such myself.

07-12-2018, 02:28 PM	#5
kypfer Pentaxian Join Date: Jan 2018 Location: Jersey C.I. Posts: 3,593 Original Poster	Originally posted by mikesbike i would assume you could input a different FL of the lens to optimize SR function? I've not tried such myself. Sorry, not quite sure what you're suggesting. On my camera, if the lens is recognised, as this particular Sigma is, there's no opportunity (that I am aware of) to change the focal length. It's only with older manual-focus lenses that I'm offered the option to enter the focal length of the lens, the option on the menu is "greyed out" when a recognised lens is fitted.