The bottom line for wide aperture shooting: understand your lens, and realize that it’s the overall visual impact that matters, not absolute sharpness. If you’re after peak sharpness, shoot at f/8.
Even the very best fast lenses have considerable aberrations wide open, which makes focus somewhat ambiguous, particularly off-center (though spherical aberration affects the entire frame). Therefore, the expectations for crisp and contrasty results must be reduced. This is true even for the US$10,500 Leica Noctilux-M ASPH, which has a truly exotic optical design, with numerous special elements (correcting an f/0.95 lens is far more stringent than for an f/1.4 lens).
Article continues for subscribers...
Already a subscriber? CLICK HERE TO LOG IN
Since 2006, Diglloyd Advanced Photography is the authoritative review and reference for DSLRs and their lenses: Canon and Nikon primarily, but also Pentax and some medium format. Reviews of key DSLRs are included, but the primary focus is on lens performance. Also included is a wealth of technique and workflow approaches.
DAP includes thousands of pages of exclusive coverage and high resolution Retina-grade examples detailing Canon and Nikon DSLR bodies and their lenses, with in-depth analysis of sharpness and contrast, color, bokeh, vignetting, distortion, MTF, and flare, behavioral and practical usage.