diff --git a/lib/PixelCanvas.lua b/lib/PixelCanvas.lua
new file mode 100644
index 0000000..d3f960d
--- /dev/null
+++ b/lib/PixelCanvas.lua
@@ -0,0 +1,40 @@
+-- Render targets measured in real framebuffer PIXELS.
+--
+-- love.graphics.newCanvas defaults its `dpiscale` to
+-- love.graphics.getDPIScale(), so on a highdpi surface the texture it
+-- allocates is NOT the size it was asked for -- newCanvas(2752, 2064) on a
+-- panel reporting a DPI scale of 2 asks the driver for 5504x4128.
+--
+-- Every target in this mod is already counted in framebuffer pixels: the
+-- free-roam scene canvas is love.graphics.getPixelDimensions() (see
+-- sceneSize in main.lua, and the 1/dpi blit the engine composites it with),
+-- the shadow map is a resolution rung, the blur pairs are the size of the
+-- image they were handed. Letting LOVE scale them a second time is the DPI
+-- factor applied twice.
+--
+-- On an iPad at DPI scale 2 that took the scene canvas past the driver's
+-- maximum texture size. newCanvas threw, beginScene returned false,
+-- drawWorld returned nil -- and returning nil IS the 2D fallback, so the
+-- engine quietly kept drawing the flat world. Every switch said the mode was
+-- on (the OPTIONS row, the mod manager, the hotkey) and nothing ever
+-- appeared. Desktop never saw it: dpiscale is 1 there.
+--
+-- getWidth()/getHeight() always report the REQUESTED size, so pinning the
+-- scale changes only the resolution of the target -- no geometry, no UV, no
+-- compositing scale anywhere moves, and the FX overlay's projected pixel
+-- coordinates finally land on the pixels they name. The engine's own render
+-- targets do this for the same reason (src/render/PixelCanvas.lua).
+
+-- the mod namespace (see main.lua)
+local V = ...
+
+local PixelCanvas = {}
+
+-- One framebuffer pixel per w/h, always. Returns ok, canvas -- the shape the
+-- pcall-guarded call sites already branch on, so a driver that refuses the
+-- allocation still degrades instead of erroring.
+function PixelCanvas.new(w, h)
+  return pcall(love.graphics.newCanvas, w, h, { dpiscale = 1 })
+end
+
+return PixelCanvas
diff --git a/lib/ShadowMap.lua b/lib/ShadowMap.lua
index 9798462..e3dd332 100644
--- a/lib/ShadowMap.lua
+++ b/lib/ShadowMap.lua
@@ -180,7 +180,9 @@ end
 local function getCanvas(res)
   if canvas == false then return nil end
   if canvas and canvasRes == res then return canvas end
-  local ok, c = pcall(love.graphics.newCanvas, res, res)
+  -- pixel-exact: `res` IS the texel count the filter's sunTexel is derived
+  -- from, so the texture must be exactly that big (see lib/PixelCanvas.lua)
+  local ok, c = V.require("PixelCanvas").new(res, res)
   if not (ok and c) then
     canvas = false
     return nil
diff --git a/lib/TiltShift.lua b/lib/TiltShift.lua
index d95c10e..a9cc66b 100644
--- a/lib/TiltShift.lua
+++ b/lib/TiltShift.lua
@@ -25,6 +25,9 @@
 -- failure -- headless, no shader support) apply() hands the canvas back
 -- untouched, so every other path is byte-for-byte what it always was.
 
+-- the mod namespace (see main.lua): V.require loads a sibling module
+local V = ...
+
 local TiltShift = {}
 
 TiltShift.level = 0
@@ -85,9 +88,12 @@ end
 
 local function getCanvases(w, h)
   if not ping or cw ~= w or ch ~= h then
-    local ok, a = pcall(love.graphics.newCanvas, w, h)
+    -- pixel-exact: w and h come from the scene canvas this pass was handed,
+    -- which is already counted in framebuffer pixels (see lib/PixelCanvas.lua)
+    local PixelCanvas = V.require("PixelCanvas")
+    local ok, a = PixelCanvas.new(w, h)
     if not ok then return nil end
-    local okB, b = pcall(love.graphics.newCanvas, w, h)
+    local okB, b = PixelCanvas.new(w, h)
     if not okB then return nil end
     -- the gaussian's fractional tap offsets need linear filtering
     a:setFilter("linear", "linear")
diff --git a/lib/Voxel3D.lua b/lib/Voxel3D.lua
index 62e98be..31e732f 100644
--- a/lib/Voxel3D.lua
+++ b/lib/Voxel3D.lua
@@ -33,6 +33,7 @@ local WorldCurve = V.require("WorldCurve")
 local Sky = V.require("Sky")
 local DayNight = V.require("DayNight")
 local GlassMask = V.require("GlassMask")
+local PixelCanvas = V.require("PixelCanvas")
 
 local Voxel3D = {}
 
@@ -540,7 +541,8 @@ function Voxel3D.beginScene(w, h, cx, cy, vw, vh, sky, slot)
   local name = slot or "world"
   local held = slots[name]
   if not (held and held.w == w and held.h == h) then
-    local ok, c = pcall(love.graphics.newCanvas, w, h)
+    -- pixel-exact: w and h are framebuffer pixels already (see PixelCanvas)
+    local ok, c = PixelCanvas.new(w, h)
     if not ok then return false end
     c:setFilter("nearest", "nearest")
     if held and held.canvas and held.canvas.release then