[Brightcolours]

Just that with a lens that lets in less light, it becomes noticable that the camera is slower in focussing.

[JJ_SO]

What has slow focus in the dark to do with the lens? We don't do camera tests ...

 

I know. But lenses are used exclusively with cameras and never alone, and if a certain lens forces the camera to switch to a slower AF-mode, the lens HAS to do something with AF. This means the APD version of the otherwise not too bad focusing 56/1.2

 

To me it was very strange to see the AF of the 50/2 nearly creeping to focus. I would love to do a comparison in similar light situations, but as I said, the 56/1.5 APD takes a stop at the service boxes of Fuji. Rattle-rattle-rattle...  a very rythmical lens in the right hands.

[Klaus]

Just that with a lens that lets in less light, it becomes noticable that the camera is slower in focussing.

 

The mirrorless AF (both PD- and CD-AF) slows down due to increased sensor noise in low light. Which increased sensor noise the readings become less accurate thus the camera has to take more readings to compensate that.

[JJ_SO]

Additionally, in AF-C mode the camera worses things by stopping down the aperture - so, no matter how fast the lens could be, it is set to working aperture.

 

Mine was wide open, in AF-S and slower as I ever had it on the old Sigma Merrills.