Get Nikon 20mm f/1.8G at B&H Photo.
Includes large crops and apertures from wide open through f/8 for all.
Focus shift is a major practical usage consideration, because lens performance is first and foremost about placing the zone of sharpness in the optimal place. No “fine focus adjust” feature compensates for focus shift (well, it could be done some innovation at Nikon that compensates by aperture).
When I’m asked to compare (for example) the Nikon 20/1.8G to the Nikon 14-24/2.8G, it’s an open-ended and demanding task: should the comparison be done focused as 99% of shooters would do (no compensation for focus shift), or to show the best possible results from each? Because the reality is that a predictable lens or camera for focusing (actual focus and focus shift) is the one that delivers the sharpest images most of the time.
Roy P writes:
Hi Lloyd, I’ve been looking at your focus shift comparisons between the Nikon 20/1.8 and the 14-24/2.8 lenses.
ince both these are autofocus lenses and neither is designed for manual focusing, wouldn’t the typical use case be AF? In that case, by definition, wouldn’t the AF focus on the subject always? So why sweat the issue, unless one is determined to use these as manual focus lenses?!
DIGLLOYD: yes of course the usual case is AF, and that’s the guaranteed worst case: the lens focuses wide open, then the shot is made stopped down. On a tripod with manual focus, one can at least focus stopped down slightly to mitigate the error. There is never any issue focusing and shooting at the same aperture.