diff --git a/croppa/main.py b/croppa/main.py
index 42cb87b..215462f 100644
--- a/croppa/main.py
+++ b/croppa/main.py
@@ -1201,14 +1201,18 @@ class VideoEditor:
 
     def _map_original_to_screen(self, ox, oy):
         """Map a point in original frame coords to canvas screen coords."""
-        cx, cy, cw, ch = self._get_effective_crop_rect_for_frame(getattr(self, 'current_frame', 0))
+        frame_number = getattr(self, 'current_frame', 0)
+        cx, cy, cw, ch = self._get_effective_crop_rect_for_frame(frame_number)
+        # Relative to effective crop
         px = ox - cx
         py = oy - cy
         angle = self.rotation_angle
+        # Dimensions after rotation
         if angle in (90, 270):
             rotated_w, rotated_h = ch, cw
         else:
             rotated_w, rotated_h = cw, ch
+        # Forward rotation mapping
         if angle == 90:
             rx, ry = py, rotated_w - px
         elif angle == 180:
@@ -1217,51 +1221,68 @@ class VideoEditor:
             rx, ry = rotated_h - py, px
         else:
             rx, ry = px, py
+        # Zoom
         zx = rx * self.zoom_factor
         zy = ry * self.zoom_factor
-        base_w, base_h = rotated_w, rotated_h
-        disp_w = int(base_w * self.zoom_factor)
-        disp_h = int(base_h * self.zoom_factor)
+        # Apply display offset cropping in zoomed space
+        new_w = int(rotated_w * self.zoom_factor)
+        new_h = int(rotated_h * self.zoom_factor)
+        offx_max = max(0, new_w - self.window_width)
+        offy_max = max(0, new_h - self.window_height)
+        offx = max(0, min(int(self.display_offset[0]), offx_max))
+        offy = max(0, min(int(self.display_offset[1]), offy_max))
+        inframe_x = zx - offx
+        inframe_y = zy - offy
+        # Size of processed_frame from apply_crop_zoom_and_rotation
+        base_w = new_w if new_w <= self.window_width else self.window_width
+        base_h = new_h if new_h <= self.window_height else self.window_height
+        # Final scale and canvas placement
         available_height = self.window_height - (0 if self.is_image_mode else self.TIMELINE_HEIGHT)
-        scale = min(self.window_width / max(1, disp_w), available_height / max(1, disp_h))
-        if scale < 1.0:
-            final_w = int(disp_w * scale)
-            final_h = int(disp_h * scale)
-        else:
-            final_w = disp_w
-            final_h = disp_h
-            scale = 1.0
-        start_x = (self.window_width - final_w) // 2
-        start_y = (available_height - final_h) // 2
-        sx = int(round(start_x + zx * scale))
-        sy = int(round(start_y + zy * scale))
+        scale = min(self.window_width / max(1, base_w), available_height / max(1, base_h))
+        final_w = int(base_w * scale)
+        final_h = int(base_h * scale)
+        start_x_canvas = (self.window_width - final_w) // 2
+        start_y_canvas = (available_height - final_h) // 2
+        sx = int(round(start_x_canvas + inframe_x * scale))
+        sy = int(round(start_y_canvas + inframe_y * scale))
         return sx, sy
 
     def _map_screen_to_original(self, sx, sy):
         """Map a point on canvas screen coords back to original frame coords."""
-        cx, cy, cw, ch = self._get_effective_crop_rect_for_frame(getattr(self, 'current_frame', 0))
+        frame_number = getattr(self, 'current_frame', 0)
+        cx, cy, cw, ch = self._get_effective_crop_rect_for_frame(frame_number)
         angle = self.rotation_angle
+        # Dimensions after rotation
         if angle in (90, 270):
             rotated_w, rotated_h = ch, cw
         else:
             rotated_w, rotated_h = cw, ch
-        disp_w = int(rotated_w * self.zoom_factor)
-        disp_h = int(rotated_h * self.zoom_factor)
+        # Zoomed dimensions and base processed dimensions (after window cropping)
+        new_w = int(rotated_w * self.zoom_factor)
+        new_h = int(rotated_h * self.zoom_factor)
+        base_w = new_w if new_w <= self.window_width else self.window_width
+        base_h = new_h if new_h <= self.window_height else self.window_height
+        # Final scaling used in display
         available_height = self.window_height - (0 if self.is_image_mode else self.TIMELINE_HEIGHT)
-        scale = min(self.window_width / max(1, disp_w), available_height / max(1, disp_h))
-        if scale < 1.0:
-            final_w = int(disp_w * scale)
-            final_h = int(disp_h * scale)
-        else:
-            final_w = disp_w
-            final_h = disp_h
-            scale = 1.0
-        start_x = (self.window_width - final_w) // 2
-        start_y = (available_height - final_h) // 2
-        zx = (sx - start_x) / max(1e-6, scale)
-        zy = (sy - start_y) / max(1e-6, scale)
+        scale = min(self.window_width / max(1, base_w), available_height / max(1, base_h))
+        final_w = int(base_w * scale)
+        final_h = int(base_h * scale)
+        start_x_canvas = (self.window_width - final_w) // 2
+        start_y_canvas = (available_height - final_h) // 2
+        # Back to processed (zoomed+cropped) space
+        zx = (sx - start_x_canvas) / max(1e-6, scale)
+        zy = (sy - start_y_canvas) / max(1e-6, scale)
+        # Add display offset in zoomed space
+        offx_max = max(0, new_w - self.window_width)
+        offy_max = max(0, new_h - self.window_height)
+        offx = max(0, min(int(self.display_offset[0]), offx_max))
+        offy = max(0, min(int(self.display_offset[1]), offy_max))
+        zx += offx
+        zy += offy
+        # Reverse zoom
         rx = zx / max(1e-6, self.zoom_factor)
         ry = zy / max(1e-6, self.zoom_factor)
+        # Reverse rotation
         if angle == 90:
             px, py = rotated_w - ry, rx
         elif angle == 180:
@@ -1270,6 +1291,7 @@ class VideoEditor:
             px, py = ry, rotated_h - rx
         else:
             px, py = rx, ry
+        # Back to original frame
         ox = px + cx
         oy = py + cy
         ox = max(0, min(int(round(ox)), self.frame_width - 1))