Ultrasonic motor

Variations in the final product are nothing unusual. In mass production, reliability gets refined, costs are optimized (though sometimes one comes at the expense of the other), and engineers make small tweaks to the design along the way. I can name several pieces of photographic gear where identical external appearance hides very different internals. But this time, Sony has outdone everyone — two completely different lenses hiding under the exact same nameplate! That’s a bit of a spoiler,

Fast autofocus lenses from the South Korean company Samyang are extremely interesting and slightly underrated. The company has journeyed from fully manual budget lenses to fully compatible autofocus models, and they've succeeded. Modern AF lenses don't just have autofocus; they're equipped with “trendy” ultrasonic motors of their own design. Considering the excellent image quality, I'd place them alongside both branded primes and general-purpose zooms. Of course, there's a bit of hardware

Among Sony E-mount lenses, the G Master and Zeiss (ZA) series stand out in particular. The G series is supposed to deliver mind-blowing image quality, fast autofocus, and record-breaking aperture speed, while the ZA line, in turn, focuses on artistic rendering (allegedly) - and fair enough, Carl Zeiss engineers did lend a hand in designing the optics! I'll leave this kind of classification to the marketing department, but from my own experience, there's nothing alien about Zeiss-branded lenses.