New Sigma lens front focuses slightly...

joeyc · 06-25-2009, 06:34 PM

Just received my Sigma 24-70mm EX F2.8 Macro. Wow - this lens has a solid feel to it. More so than any digital Zuiko or prior Sigma lens. Focus is quick and images seem sharp - even wide open, but it does appear to front focus slightly - about 1-2 cm. Not much and so far is not evident in normal shots, but with close-up (or quasi-macro) shots it is apparent.

What's best, send it back to the store and hope for a better or copy (and risk a worse copy) or send it back to Sigma? It stinks to have to do this after just receiving it, but I knew buying Sigma meant this possibility.

Thanks.

5teve · 06-25-2009, 07:22 PM

what camera? the k20 you can adjust..

are you also shooting under tungsten.. as i got caught out with that

thanks

steve

joeyc · 06-25-2009, 08:00 PM

Sorry - K200D. Does the lighting affect the ability to accurately focus? It was indoors - mixed lighting.

Originally posted by 5teve

what camera? the k20 you can adjust..

are you also shooting under tungsten.. as i got caught out with that

thanks

steve

imtheguy · 06-25-2009, 08:46 PM

Originally posted by joeyc

Sorry - K200D. Does the lighting affect the ability to accurately focus? It was indoors - mixed lighting.

Please go to the #11 post in this thread where I got my ears pinned back

with information new to me on the lighting wavelength effect on focusing accuracy.
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/64170-da-16-45-questions.html

Last edited by imtheguy; 06-25-2009 at 08:55 PM.

joeyc · 06-25-2009, 08:51 PM

Originally posted by imtheguy

Please go to the #11 post in this thread where I got my ears pinned back

with information new to me on the lighting wavelenght effect on focusing accuracy.
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/64170-da-16-45-questions.html

Thanks for the link... Very interesting to me. I never experienced this before with Olympus or Nikon. I will have to do some testing outside to rule out the lens.

Marc Sabatella · 06-26-2009, 09:43 AM

Originally posted by joeyc

Thanks for the link... Very interesting to me. I never experienced this before with Olympus or Nikon.

Did you test for it? As far as I know, they are not immune from the physics that causes this phenomenon.

joeyc · 06-26-2009, 09:48 AM

Yes, I tested it. I'm sure it occurs - I suppose I was fortunate. I have heard of more issues with Nikon than Olympus, but like you said all manufacturers could be open to this issue.

joeyc · 06-26-2009, 04:04 PM

Did some quick rudimentry tests outside. Focus wide open was spot on. Must have been the lighting. I will certainly monitor this to make sure there isn't an issue. I appreciate the help.

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06-25-2009, 06:34 PM	#1
joeyc Veteran Member Join Date: Jun 2009 Location: Philadelphia Posts: 478	New Sigma lens front focuses slightly... Just received my Sigma 24-70mm EX F2.8 Macro. Wow - this lens has a solid feel to it. More so than any digital Zuiko or prior Sigma lens. Focus is quick and images seem sharp - even wide open, but it does appear to front focus slightly - about 1-2 cm. Not much and so far is not evident in normal shots, but with close-up (or quasi-macro) shots it is apparent. What's best, send it back to the store and hope for a better or copy (and risk a worse copy) or send it back to Sigma? It stinks to have to do this after just receiving it, but I knew buying Sigma meant this possibility. Thanks.

06-25-2009, 07:22 PM	#2
5teve Senior Member Join Date: Mar 2009 Location: Perth - Australia Photos: Albums Posts: 226	what camera? the k20 you can adjust.. are you also shooting under tungsten.. as i got caught out with that thanks steve

06-25-2009, 08:00 PM	#3
joeyc Veteran Member Join Date: Jun 2009 Location: Philadelphia Posts: 478 Original Poster	Sorry - K200D. Does the lighting affect the ability to accurately focus? It was indoors - mixed lighting. Originally posted by 5teve what camera? the k20 you can adjust.. are you also shooting under tungsten.. as i got caught out with that thanks steve

06-25-2009, 08:46 PM	#4
imtheguy Site Supporter Join Date: Mar 2009 Location: Virginia Beach Photos: Gallery \| Albums Posts: 2,950	Originally posted by joeyc Sorry - K200D. Does the lighting affect the ability to accurately focus? It was indoors - mixed lighting. Please go to the #11 post in this thread where I got my ears pinned back with information new to me on the lighting wavelength effect on focusing accuracy. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/64170-da-16-45-questions.html Last edited by imtheguy; 06-25-2009 at 08:55 PM.

06-25-2009, 08:51 PM	#5
joeyc Veteran Member Join Date: Jun 2009 Location: Philadelphia Posts: 478 Original Poster	Originally posted by imtheguy Please go to the #11 post in this thread where I got my ears pinned back with information new to me on the lighting wavelenght effect on focusing accuracy. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/64170-da-16-45-questions.html Thanks for the link... Very interesting to me. I never experienced this before with Olympus or Nikon. I will have to do some testing outside to rule out the lens.

06-26-2009, 09:43 AM	#6
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by joeyc Thanks for the link... Very interesting to me. I never experienced this before with Olympus or Nikon. Did you test for it? As far as I know, they are not immune from the physics that causes this phenomenon.

06-26-2009, 09:48 AM	#7
joeyc Veteran Member Join Date: Jun 2009 Location: Philadelphia Posts: 478 Original Poster	Yes, I tested it. I'm sure it occurs - I suppose I was fortunate. I have heard of more issues with Nikon than Olympus, but like you said all manufacturers could be open to this issue.

06-26-2009, 04:04 PM	#8
joeyc Veteran Member Join Date: Jun 2009 Location: Philadelphia Posts: 478 Original Poster	Did some quick rudimentry tests outside. Focus wide open was spot on. Must have been the lighting. I will certainly monitor this to make sure there isn't an issue. I appreciate the help.