K-5 and Sigma 10mm Fisheye issue?

Qwntm · 04-29-2012, 05:09 PM

So my 10mm Sigma Fisheye seems to not want to play nice with the K-5's IS system. When IS is on, the shots are blurry. When I turn the IS off the shots are fine. ISO 400, f2.8, 1/25th.

Anyone else have this issue?

It's no big deal as IS isn't that critical at 10mm anyway, but it's annoying to have to remember to turn IS OFF in order to get a non blurry shot!

Adam · 04-29-2012, 05:20 PM

Are you letting the SR system arm before taking your shot?

Also, it could be the case that SR is over-compensating, as a 10mm fisheye is wider than a 10mm rectilinear lens would be. If that's the case, only a firmware update would fix the problem.

**dms** · 04-29-2012, 06:59 PM

I don't have any fish eye lenses--but it is an interesting point. In general how does the shake reduction work when the lens projects the image onto a sphere?

AFAIK near the edges the "effective focal length" is shorter than the center and setting the SR for the center--or lens overall--means it is over-correcting at the periphery. Seems like one should not use SR, or bias it for the edges. Anyone know?

Bob from Aus · 04-29-2012, 08:37 PM

I assume IS = SR = shake reduction. Never had any issues with my Sigma 10mm with my K5s or K7. I love using it for very close photos. I never turn my SR off. The only problem I have is accidentally turning the lens switch onto manual focus and the having an electric motor to focus not realizing the focus is off.

I will keep a look out to see if there is an issue I haven't noticed.

Qwntm · 04-30-2012, 01:48 PM

Originally posted by Bob from Aus

I assume IS = SR = shake reduction. Never had any issues with my Sigma 10mm with my K5s or K7. I love using it for very close photos. I never turn my SR off. The only problem I have is accidentally turning the lens switch onto manual focus and the having an electric motor to focus not realizing the focus is off.

I will keep a look out to see if there is an issue I haven't noticed.

Oops! Too many years shooting Canon! yep, SR, not IS sorry!

Interesting. I'll have to try the lens on another K-5 body. So far it's just the one. It's a new lens and there is the possibility there is something wrong. That's why I'm asking. I am letting the SR arm. More testing!

Thanks for the help!

alspe · 05-29-2012, 11:56 PM

Originally posted by Bob from Aus

I assume IS = SR = shake reduction. Never had any issues with my Sigma 10mm with my K5s or K7. I love using it for very close photos. I never turn my SR off. The only problem I have is accidentally turning the lens switch onto manual focus and the having an electric motor to focus not realizing the focus is off.

I will keep a look out to see if there is an issue I haven't noticed.

Interesting, I got my Sigma 10mm fisheye yesterday and have not got one single picture without blur when SR on. When SR is off, picture is sharp.

04-29-2012, 05:09 PM	#1
Qwntm Veteran Member Join Date: Jul 2011 Location: Eastern Oregon Posts: 856	K-5 and Sigma 10mm Fisheye issue? So my 10mm Sigma Fisheye seems to not want to play nice with the K-5's IS system. When IS is on, the shots are blurry. When I turn the IS off the shots are fine. ISO 400, f2.8, 1/25th. Anyone else have this issue? It's no big deal as IS isn't that critical at 10mm anyway, but it's annoying to have to remember to turn IS OFF in order to get a non blurry shot!

04-29-2012, 05:20 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Are you letting the SR system arm before taking your shot? Also, it could be the case that SR is over-compensating, as a 10mm fisheye is wider than a 10mm rectilinear lens would be. If that's the case, only a firmware update would fix the problem. 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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04-29-2012, 06:59 PM	#3
dms Site Supporter Join Date: Aug 2011 Location: New York, NY Photos: Gallery Posts: 2,192	I don't have any fish eye lenses--but it is an interesting point. In general how does the shake reduction work when the lens projects the image onto a sphere? AFAIK near the edges the "effective focal length" is shorter than the center and setting the SR for the center--or lens overall--means it is over-correcting at the periphery. Seems like one should not use SR, or bias it for the edges. Anyone know?

04-29-2012, 08:37 PM	#4
Bob from Aus Veteran Member Join Date: Jul 2011 Location: Australia Photos: Gallery Posts: 1,094	I assume IS = SR = shake reduction. Never had any issues with my Sigma 10mm with my K5s or K7. I love using it for very close photos. I never turn my SR off. The only problem I have is accidentally turning the lens switch onto manual focus and the having an electric motor to focus not realizing the focus is off. I will keep a look out to see if there is an issue I haven't noticed.

04-30-2012, 01:48 PM	#5
Qwntm Veteran Member Join Date: Jul 2011 Location: Eastern Oregon Posts: 856 Original Poster	Originally posted by Bob from Aus I assume IS = SR = shake reduction. Never had any issues with my Sigma 10mm with my K5s or K7. I love using it for very close photos. I never turn my SR off. The only problem I have is accidentally turning the lens switch onto manual focus and the having an electric motor to focus not realizing the focus is off. I will keep a look out to see if there is an issue I haven't noticed. Oops! Too many years shooting Canon! yep, SR, not IS sorry! Interesting. I'll have to try the lens on another K-5 body. So far it's just the one. It's a new lens and there is the possibility there is something wrong. That's why I'm asking. I am letting the SR arm. More testing! Thanks for the help!

05-29-2012, 11:56 PM	#6
alspe Junior Member Join Date: Mar 2012 Posts: 36	Originally posted by Bob from Aus I assume IS = SR = shake reduction. Never had any issues with my Sigma 10mm with my K5s or K7. I love using it for very close photos. I never turn my SR off. The only problem I have is accidentally turning the lens switch onto manual focus and the having an electric motor to focus not realizing the focus is off. I will keep a look out to see if there is an issue I haven't noticed. Interesting, I got my Sigma 10mm fisheye yesterday and have not got one single picture without blur when SR on. When SR is off, picture is sharp.

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