Focus lock preserves a focus setting; it does not continuously compensate when the camera or subject moves to a new distance. If a portrait was sharp at focus confirmation but soft after you stepped, leaned, or recomposed, check that distance change first. Reacquire focus at the final position rather than relying on the earlier confirmation as proof that the delivered frame is sharp.
Record the sequence before diagnosing the lens
Write down what happened between focusing and release. Did you lean toward the subject, did the person move, or did you keep holding a lock while taking several different compositions? Nikon's focus-lock instructions explicitly say to maintain camera-to-subject distance and refocus when it changes. Those instructions are a useful starting point for checking technique.
A focus-confirmation indicator is a moment in the workflow, not a certificate attached to every later image. The near eye, far eye, and background can also occupy different distances. Examine the actual required feature in the file instead of concluding from a small camera preview that the whole face is equally sharp.
Compare two capture methods
This is an unexecuted test plan for a cooperative, stationary portrait subject or a harmless textured stand-in. Mark a comfortable camera position and keep the lighting steady. Record focal length, aperture, shutter speed, autofocus mode, and which feature receives focus. Take several frames with the final composition established before focusing.
Then repeat your usual focus-lock-and-recompose sequence, noting any step or lean. Finally, use the recomposed position but deliberately refocus on the required feature before release. Compare matching eye or texture crops at the same scale. Keep all frames rather than choosing only the best from one method. The result can show whether your sequence contributes to the problem; it does not automatically diagnose lens calibration.
Match the focus strategy to the portrait
For a still headshot, placing the intended feature under an appropriate focus point in the final composition may reduce unnecessary movement. For a moving subject, the camera's supported continuous or tracking autofocus may be more appropriate than maintaining an old lock. The mode names, priority behavior, and available detection differ by body; verify them in that model's manual.
If both methods remain soft, continue with lighting, motion, lens limits, and equipment checks. Do not keep repeating a test that changes every variable at once. Also avoid asking the subject to hold an uncomfortable pose merely to compensate for an unexamined capture sequence.
Before an Imagild portrait transformation, choose a source where the eyes and identity anchors needed by the brief are genuinely readable. Retain the other originals and use them only for the details they actually show. Generative sharpening can produce convincing eyelashes, but it cannot verify that invented detail matches the person. Correcting the capture gives a stronger starting reference.