Focus Peaking for Manual Control: RF 35mm f/1.8 IS Macro STM
Focus peaking is an EVF overlay that highlights in-focus edges in a selected color — typically red, yellow, or white — as you rotate the focus ring. It is a mirrorless-native feature, unavailable on optical viewfinders by definition, and it changes the character of manual focus work on modern cameras in ways that make the technique accessible where it was previously a specialist skill.
The RF 35mm f/1.8 IS Macro STM has a smooth, well-damped manual focus ring with enough rotation travel to be used precisely. On an R-series body, set MF Peaking to Level High, color to yellow (the highest contrast against most scenes), and switch the lens to MF mode either via the lens switch or the camera menu. As you rotate the focus ring, yellow fringing appears on the edges that are entering the focal plane.
The value of this over AF in specific situations: at close focus distances, particularly approaching the Macro STM’s closest focus, servo AF can hunt or lock onto the wrong plane — especially when the subject has fine detail across multiple depth planes. Manually focusing while watching the peaking overlay gives you direct control over which plane the camera resolves. You pick the plane. The camera shows you where it is.
The limitation of peaking is that it is an approximation. High-contrast edges that are slightly out of focus can still trigger the peaking highlight at Level High sensitivity. For critical focus — a single eyelash at close portrait distance, the stamen of a flower at Macro range — use focus magnification at 5x or 10x as confirmation after peaking indicates you are close. The R-series bodies allow you to assign magnification to a button, making the two-step workflow fast enough to use in field conditions.
Peaking plus magnification is not slower than reliable AF. For difficult subject planes it is faster, because you eliminate the hunt entirely.
Manual focus is not a nostalgic affectation. On a modern mirrorless body, it is a precision instrument.