diff --git a/dev/calibration_test.star b/dev/calibration_test.star
index ca5232c..e4c657d 100644
--- a/dev/calibration_test.star
+++ b/dev/calibration_test.star
@@ -30,7 +30,7 @@ ART_ZOOM_DURATION = 200
 def _art_widget(art_bytes, zoom_scale):
     art = render.Image(src = art_bytes, width = ART_SIZE, height = ART_SIZE)
     top_scale = max(zoom_scale, 1.0)
-    shift = (1.0 - top_scale) * (ART_SIZE / 2.0) / top_scale
+    shift = (1.0 - top_scale) * (ART_SIZE / 2.0)
     zoom = animation.Transformation(
         child = art,
         duration = ART_ZOOM_DURATION,
diff --git a/subwave_nowplaying.star b/subwave_nowplaying.star
index 2ddf611..03c91cd 100644
--- a/subwave_nowplaying.star
+++ b/subwave_nowplaying.star
@@ -91,12 +91,16 @@ COLOR_SCHEMES = {
 DEFAULT_COLOR_SCHEME = "cyberpunk"  # matches the station's own site theme
 
 # How far in the album art zoom goes, relative to its fully-zoomed-out rest
-# state (see _art_widget below for why scale never goes below 1.0).
+# state (see _art_widget below for why scale never goes below 1.0). "strong"
+# is capped at 1.45, not pushed further: with the centering Translate in
+# _art_widget, empirically anything above ~1.46 starts revealing a real
+# black border in the bottom-right corner (verified with the calibration
+# tool) -- this is the safe ceiling, not an arbitrary choice.
 ZOOM_LEVELS = {
     "off": 1.0,
     "subtle": 1.15,
     "moderate": 1.4,
-    "strong": 1.7,
+    "strong": 1.45,
 }
 DEFAULT_ZOOM_LEVEL = "moderate"
 
@@ -233,21 +237,19 @@ def _art_widget(art_bytes, zoom_scale):
     # Scale with a Translate re-centers the zoom so it crops evenly from
     # all sides instead -- verified against a calibration grid image.
     #
-    # The naive "final pixel shift" formula, (1-s)*(ART_SIZE/2), looked
-    # right at a moderate zoom (1.4x) but pushed past the image's actual
-    # edge at a strong one (1.7x) -- a real, on-device black border in the
-    # bottom-right corner. That means Translate isn't applied in final
-    # output pixels here; empirically, dividing by `top_scale` keeps the
-    # crop inside the image's bounds at every zoom level this app offers
-    # (verified via the calibration tool at both 1.4x and 1.7x), at the
-    # cost of the *most* extreme (1.7x) zoom being very slightly
-    # off-center rather than perfectly centered -- a trade worth making
-    # since going outside the art's bounds is worse than a slight
-    # asymmetry. This is safe because scale never drops below 1.0 here:
-    # the black-border bug from an earlier version came from combining
-    # Translate with scale *below* 1.0, not from Translate itself.
+    # shift = (1-s)*(ART_SIZE/2) is linear in the scale value, which keeps
+    # it moving smoothly in lockstep with Scale's own eased interpolation
+    # throughout the animation. A tempting "fix" for a black-border bug at
+    # strong zoom was dividing this by `top_scale` to pull the shift in at
+    # high scale values -- that avoided the border, but made the shift a
+    # *nonlinear* function of the scale being interpolated, so partway
+    # through the animation the pan no longer tracked the zoom at a
+    # constant rate -- visibly jerky. Reverted: instead, ZOOM_LEVELS caps
+    # "strong" at a value where this plain linear formula is already safe
+    # (verified via the calibration tool), rather than changing the
+    # formula's shape.
     top_scale = max(zoom_scale, 1.0)
-    shift = (1.0 - top_scale) * (ART_SIZE / 2.0) / top_scale
+    shift = (1.0 - top_scale) * (ART_SIZE / 2.0)
     zoom = animation.Transformation(
         child = art,
         duration = ART_ZOOM_DURATION,