Sigma FE 14mm f/1.8 DG HSM Art Aperture Series and Field Curvature and Focus Shift Analysis: Lingering Snow
Sometimes it takes just the right scene to make plain the actual lens behavior, which can be difficult to analyze on many scenes due to the choice of focus versus 3D structure of the scene versus optical behavior.
This scene extends the field curvature analysis in Hiker at Upper Conness Lake. It proves to be a remarkable demonstration of both field curvature and mid-zone focus shift which should persuade anyone of the near-irrelevance of “quick tests” or lab tests which purport to show lens performance in real world shooting.
Optical designs often must be compromised in some way to balance out competing challenges, particularly with ultra wide lenses. These compromises increase with fast lens speed. This is why I generally frown upon fast wide angle lenses for my work: not only are the compromises generally troublesome, but the lenses become bulky and unwieldy and too heavy.
Images at sizes up to full camera resolution from f/1.8 through f/11.