[fix] In binary autofocus move to best position even when minimum ste…

…psize is reached (#2840)

Break the loop after moving to the best position: Otherwise the focus will not be at the best position
when clipping left and right have caused left and right to be equal, but them not being equal to the center / best position.

src/odemis/acq/align/autofocus.py

@@ -313,10 +313,6 @@ def _DoBinaryFocus(future, detector, emt, focus, dfbkg, good_focus, rng_focus):
             if future._autofocus_state == CANCELLED:
                 raise CancelledError()
 
-            if left == right:
-                logging.info("Seems to have reached minimum step size (at %g m)", 2 * step_factor * min_step)
-                break
-
             # if best focus was found at the center
             if i_max == 1:
                 step_factor /= 2
@@ -335,6 +331,13 @@ def _DoBinaryFocus(future, detector, emt, focus, dfbkg, good_focus, rng_focus):
                 # Clip best_pos in case the hardware reports a position outside of the range.
                 best_pos = max(rng[0], min(best_pos, rng[1]))
                 focus.moveAbsSync({"z": best_pos})
+
+            if left == right:
+                # Do this after moving to the best position, because clipping left and right can cause
+                # left and right to be equal, even when both are unequal to the best position.
+                logging.info("Seems to have reached minimum step size (at %g m)", 2 * step_factor * min_step)
+                break
+
             step_cntr += 1
 
         worst_fm = min(focus_levels.values())