it's kind of the reverse problem of LCD viewing angles. film had no structure, but each pixel on a sensor is at the bottom of a tiny little well looking out. th

it's kind of the reverse problem of LCD viewing angles. film had no structure, but each pixel on a sensor is at the bottom of a tiny little well looking out. the effect is exacerbated on mirrorless with a shorter flange distance. the modern Nikon sensors are currently the best here, being designed with adaptation in mind. but it doesn't matter so much, the worst you might see is a fractional stop of additional vignetting. it matters even less if you're adapting an SLR lens with a deeper flange.