Uploaded December 2023 | Updated September 2026, 2 hours ago
Demonstration of how Nikon's AF-S focus mode on Z cameras doesn't actually focus just once and stop but instead continuously resamples focus of the target, akin to AF-C, likely as a measure to correct any potential lens movement imprecision or variance, in addition to other possible reasons. This behavior isn't unique to Nikon cameras - this "open loop" method of focus has been documented before, the seminal work being from a Dpreview member named WilbaW in his article "Busted! The Myth of Open-loop Phase-detection Autofocus", which can be read at dpreview.com/articles/5402438893/busted-the-myth-of-open-loop-phase-detection-autofocus
Demonstration of how Nikon's AF-S focus mode on Z cameras doesn't actually focus just once and stop but instead continuously resamples focus of the target, akin to AF-C, likely as a measure to correct any potential lens movement imprecision or variance, in addition to other possible reasons. This behavior isn't unique to Nikon cameras - this "open loop" method of focus has been documented before, the seminal work being from a Dpreview member named WilbaW in his article "Busted! The Myth of Open-loop Phase-detection Autofocus", which can be read at dpreview.com/articles/5402438893/busted-the-myth-of-open-loop-phase-detection-autofocus
