Zeiss is a world-renowned expert in optics, so anything featuring its glass inevitably comes with a premium price tag, including its own SFL 10x50 binoculars. But why ‘SFL’? In Zeiss’s world, this stands for ‘Smart Focus’ and ‘Lightweight’. While the 'Lightweight' aspect is self-explanatory, the Japanese-made binos' blurb suggests ‘Smart Focus’ relates to the positioning of a large, ridged focus wheel between the eyepieces. There’s nothing unusual about this control’s centralized location, or anything noticeably ‘smart’ about it, but its maker insists its ergonomics enable fast focus adjustment. Which I wouldn’t argue with: its tactile and responsive functionality is undoubtedly useful for tracking moving wildlife.
I believe the jewel in this model’s crown, however, is its ultra-high definition 50mm objective lenses. The manufacturer says that it has managed to squeeze these into a traditional 42mm frame size. What’s more, the combination of 50mm lenses and larger exit pupils is claimed to allow for 42% more light than competing 42mm binoculars. The result, to my eyes, is a noticeably brighter image than expected from a device of this size.
