Opticallimits
Nikkor AF-S 70-200mm f/4 focus shift - Printable Version

+- Opticallimits (https://forum.opticallimits.com)
+-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4)
+--- Forum: Just Talk (https://forum.opticallimits.com/forumdisplay.php?fid=17)
+--- Thread: Nikkor AF-S 70-200mm f/4 focus shift (/showthread.php?tid=1418)



Nikkor AF-S 70-200mm f/4 focus shift - smukec - 08-23-2014

The author of Sigma AF 70-200mm f/2.8 EX OS HSM test is writing about focus shift at 200mm: "At the long end of the zoom range, the lens shows a small amount of focus shift when stopping down (residual spherical aberration)."

Sigma link: http://www.opticallimits.com/nikon--nikkor-aps-c-lens-tests/833-sigmaex7020028os?start=1

 

What about Nikkor AF-S 70-200mm f/4 here: http://www.opticallimits.com/nikon--nikkor-aps-c-lens-tests/785-nikonafs702004vrdx?start=1 ?

 

If I understand correctly focus point is always at the line where is number 100 (and 15)?

 

- at f4 (200mm) you see number 100 is in focus
- at f5.6 (200mm) you see 100 is not totaly in focus, dof is going towards 90
- at f8 (200mm) you see 100 is not totaly in focus, dof is going towards 90
- at f11 (200mm) you see 100 is not totaly in focus, dof is going towards 90
 
So I can't have subject in focus at 200mm and f5.6, f8, f11. Is that normal?
 
Nikkor AF-S 70-200mm f/2.8 G ED VR II does not have this problem. Number 100 is always in focus:
http://www.opticallimits.com/nikon_ff/511-nikkorafs7020028vr2ff?start=1