What technique keeps both eyes in focus with a 50mm at f/1.8?

[RyanHP]

I’m trying to improve my portrait work and keep hearing I should use a prime lens for that shallow depth of field look. I bought a fast 50mm, but I’m finding it really hard to get both eyes in sharp focus when my subject is turned at even a slight angle, especially at f/1.8. I end up with one eye crisp and the other softly blurred, which just feels off.

[LilyNL]

I get it. with a fast 50 at f1.8 the DoF is razor thin. The moment the head turns even a little, one eye goes soft. I solved it by backing up a bit and using an 85mm prime lens for portraits, or at least stopping down to f2.8 or f3.5 when I stay near the same distance. It buys you room to keep both eyes sharp.

[CamilaFJ]

I tried sticking the AF point on the nearer eye and re-framing, but with a slight turn the eyes still drift out of focus; sometimes I swear the camera hunts during the blink. I know it’s not a big deal on 1.8, but it feels wrong.

[BrianYW]

One thing I wonder is whether you’re actually focusing on the eye or on the nose/cheek when you recompose. Do you lock focus, then recompose, or use live view magnification?

[PatrickT]

Back when I was rushing, I just blamed the lens and moved on, but later I realized lighting and posing also play a role; a subtle tilt and short shutter can make the eyes read differently. Sometimes I just shoot at f/2 and accept a bit of blur on the far eye rather than fight with the DoF.