I recently upgraded from a D40 to a used D7000 and have been generally pleased. However, when using my Sigma 18-250 lens, I've noticed nearly all of my photos look pretty bad. It's not a stellar lens by any means, but it used to take some pretty decent pictures with my D40. I've played with the AF Fine Tune setting on the D7000 and I'm wondering if this lens just isn't responding to the tune. I think I have a slight back focus problem, but no amount of adjustment seems to make a difference (see images below).
I've read of some compatibility issues with Sigma lenses and the D7000, but I couldn't find any specific examples where a lens wouldn't respond to AF adjustment. Do I just have a bum lens? Should I try sending it in for service? Ultimately, this lens will be replaced by a trio of some faster glass, but I need this to get me by until I can save up some more $$$.
f/6.3 @ 250 mm
Focused on front edge of paper, inline with the 15" marking
Are you saving fine tune values and then reshooting There appears to be no change from "0"
to +/-20 That's not a very good testing set-up either. The demands of a 16MP sensor will be
SO much greater than that of the 6MP D40's...just sayin' Never heard of specific Sigma/D7K
issues. Been shootin' them for 2 1/2 yrs with every lens imaginable. Send it in and GL.
Given the photos, I would be happy and go out and shoot the best photos I can with a less-than-spectacular lens. AND a zoom lens that would be troublesome to fine-tune anyway.
For what it's worth, the "Sigma incompatibility" issues have all been concerning focus in live view. This doesn't work with my Sigma lenses and D7000 and I am not particularly surprised that it doesn't. Of course phase-detect works fine.
trenchmonkey wrote:
Are you saving fine tune values and then reshooting There appears to be no change from "0"
to +/-20 That's not a very good testing set-up either.
Yes, I am saving the values.
With regards to the testing setup, I've tried doing similar tests with a model (aka my wife) and setting the focus on her eye. I figured that had too many variables and had just read about this type of setup on fstoppers.com yesterday, so it reminded me of the issue I was having. I thought maybe some FMers may have had a similar problem.
I have a 24-70, 2.8 Sigma. I did a similar type test, but mine did change. I did notice going from landscape to vertical shooting, the focus changed big time. Using single focus on the same spot showed me that not all was focused across the lens, the lens will go into sigma for checking/
trenchmonkey wrote:
Are you saving fine tune values and then reshooting There appears to be no change from "0"
to +/-20 That's not a very good testing set-up either. The demands of a 16MP sensor will be
SO much greater than that of the 6MP D40's...just sayin' Never heard of specific Sigma/D7K
issues. Been shootin' them for 2 1/2 yrs with every lens imaginable. Send it in and GL.
Chambuzz wrote:
I recently upgraded from a D40 to a used D7000 and have been generally pleased. However, when using my Sigma 18-250 lens, I've noticed nearly all of my photos look pretty bad. It's not a stellar lens by any means, but it used to take some pretty decent pictures with my D40. I've played with the AF Fine Tune setting on the D7000 and I'm wondering if this lens just isn't responding to the tune. I think I have a slight back focus problem, but no amount of adjustment seems to make a difference (see images below).
I've read of some compatibility issues with Sigma lenses and the D7000, but I couldn't find any specific examples where a lens wouldn't respond to AF adjustment. Do I just have a bum lens? Should I try sending it in for service? Ultimately, this lens will be replaced by a trio of some faster glass, but I need this to get me by until I can save up some more $$$.
f/6.3 @ 250 mm
Focused on front edge of paper, inline with the 15" marking
Have you tried the dot tune method.. i just went through that exercise on 4 of my lenses and it worked pretty darn well.. but i will get some more extensive testing done this weekend..
and yes.. all 4 needed some tuning.. varying from -11 to +14
i have a d7k and a new d71k.. i can tell you definitively that the better the sensor the more you will have to work.. Shots that were what i would consider pretty good on my d7k are not up to par on my d71k. Much more attention needs to be paid to proper technique and exposure.. it really showed all my sloppiness and i am having to slow down and get it right with the d71k.. great glass also helps of course.. hehe
There appears to be no change from "0"
That's not a very good testing set-up either. The demands of a 16MP sensor will be
Never heard of specific Sigma/D7K 
it IS the Sigmeister 35, Rich...thanks! 