New answers tagged canon-60d
In Canon 6D you can set up AF micro adjustments for lenses you have. That may improve sharpness a bit. There is also ISO 50 mode that is turned of by default.
Digital Lightcraft gave the correct answer but I'd like to add that you can disable the automatic locking from the menu - the fourth tab from the right, lowest item ("Lock" and a wheel icon).
I believe that the "obvious" change here should not be underestimated. After my recent switch from APS-C (Canon) to full frame (Nikon) even with the brand change and the different user interface my biggest challenge are implications of DOF and the fact that because of that the focusing needs to be much more exact.
It sounds like your control wheel is "locked" - press the button underneath it called "unlock" This should now let you control the aperture.
Top 50 recent answers are included