diff --git a/aniphallow.lua b/aniphallow.lua
index 8c44f13..68fe805 100644
--- a/aniphallow.lua
+++ b/aniphallow.lua
@@ -1425,12 +1425,9 @@ openPreviewWindow = function()
                     local sy = S.previewStaScrollY
                     local sw = S.sourceImage.width * z
                     local sh = S.sourceImage.height * z
-                    if S.useBgColor then
-                        gc.color = S.bgColor
-                        gc:fillRect(Rectangle(sx, sy, sw, sh))
-                    else
-                        drawCheckerboard(gc, sw, sh, z, sx, sy)
-                    end
+                    -- Use solid bg instead of checkerboard for performance
+                    gc.color = S.useBgColor and S.bgColor or Color(50, 50, 50)
+                    gc:fillRect(Rectangle(sx, sy, sw, sh))
                     gc:drawImage(S.sourceImage,
                         Rectangle(0, 0, S.sourceImage.width, S.sourceImage.height),
                         Rectangle(sx, sy, sw, sh))
@@ -1581,8 +1578,10 @@ openPreviewWindow = function()
     previewTimer = Timer{
         interval = S.animSpeed / 1000.0,
         ontick = function()
-            pvAnimFrame.value = pvAnimFrame.value + 1
-            pcall(function() previewDlg:repaint() end)
+            if S.previewMode ~= "static" then
+                pvAnimFrame.value = pvAnimFrame.value + 1
+                pcall(function() previewDlg:repaint() end)
+            end
         end
     }
     previewTimer:start()
@@ -1590,9 +1589,17 @@ openPreviewWindow = function()
     pvRefreshTimer = Timer{
         interval = 0.5,
         ontick = function()
+            local prevImg = S.sourceImage
             refreshSource()
             refreshLockFile()
-            pcall(function() previewDlg:repaint() end)
+            -- In static mode, only repaint if source image changed
+            if S.previewMode == "static" then
+                if S.sourceImage ~= prevImg then
+                    pcall(function() previewDlg:repaint() end)
+                end
+            else
+                pcall(function() previewDlg:repaint() end)
+            end
 
             -- Auto-detect file change
             local currentFile = app.sprite and app.sprite.filename or ""