I tested the lens on Nikon D800 and was pleasantly surprised by the results. Sigma 24mm ƒ 1.4 has capability to produce superb images regardless of light conditions. I used it in high contrast situation, shooting from dark areas towards highlights and there was negligible chromatic aberration. Also, the sharpness* was remarkable at ƒ8-ƒ11.
*Details from above image
Weighing little less then 700gms it feels heavier for a block lens. With 15 elements in 11 groups and the use of special low dispersion elements with superb nine aperture blades Sigma 24mm ƒ1.4 is ergonomically very well designed. The grip feels right and the manual focus ring is startling. I had some issues with AF/M knob (which I felt was not smooth enough to switch). Focusing at AF is pretty fast, effortless, accurate and amazingly quiet (which I feel is a great advantage for shooting videos). Also, what comes handy is the filter size, like most of the professional lenses it has a filter size of 77mm.
I was also pleased by the degree of distortion, which I felt was minimal considering the 24mm wide-angle lens. Though there were slight signs of vignetting in extreme conditions but not so much to take away your attention. Despite of this it is praiseworthy how this lens captures the detail in both highlights and shadow areas.
I haven’t personally tried my hands on SIGMA Art series 35mm ƒ1.4 and 50mm ƒ1.4 but I have a feeling that with the excellent optical performance this 24mm ƒ1.4 will shine as bright as its very own progenitors.
Despite of it’s weight I will carry this on my next travel assignment and heavily recommend 24mm ƒ1.4 for Nikon full frame user be it landscape or low light photography or videography!