diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm
index d07d9e3f1..926bc9494 100644
--- a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
@@ -85,6 +85,9 @@ using BufferingScanTarget = Outputs::Display::BufferingScanTarget;
 		_scanTarget.set_write_area(reinterpret_cast<uint8_t *>(_writeAreaBuffer.contents));
 		_scanTarget.set_line_buffer(reinterpret_cast<BufferingScanTarget::Line *>(_linesBuffer.contents), _lineMetadataBuffer, NumBufferedLines);
 		_scanTarget.set_scan_buffer(reinterpret_cast<BufferingScanTarget::Scan *>(_scansBuffer.contents), NumBufferedScans);
+
+		// Set initial aspect-ratio multiplier.
+		[self mtkView:view drawableSizeWillChange:view.drawableSize];
 	}
 
 	return self;
@@ -124,7 +127,7 @@ using BufferingScanTarget = Outputs::Display::BufferingScanTarget;
 			case 2: pixelFormat = MTLPixelFormatRG8Unorm;	break;
 			case 4: pixelFormat = MTLPixelFormatRGBA8Unorm;	break;
 		}
-		MTLTextureDescriptor *textureDescriptor = [MTLTextureDescriptor
+		MTLTextureDescriptor *const textureDescriptor = [MTLTextureDescriptor
 			texture2DDescriptorWithPixelFormat:pixelFormat
 			width:BufferingScanTarget::WriteAreaWidth
 			height:BufferingScanTarget::WriteAreaHeight
@@ -132,18 +135,29 @@ using BufferingScanTarget = Outputs::Display::BufferingScanTarget;
 		textureDescriptor.resourceOptions = SharedResourceOptionsTexture;
 
 		// TODO: the call below is the only reason why this project now requires macOS 10.13; is it all that helpful versus just uploading each frame?
+		const NSUInteger bytesPerRow = BufferingScanTarget::WriteAreaWidth * _bytesPerInputPixel;
 		_writeAreaTexture = [_writeAreaBuffer
 			newTextureWithDescriptor:textureDescriptor
 			offset:0
-			bytesPerRow:BufferingScanTarget::WriteAreaWidth * _bytesPerInputPixel];
-		_totalTextureBytes = BufferingScanTarget::WriteAreaWidth * BufferingScanTarget::WriteAreaHeight * _bytesPerInputPixel;
+			bytesPerRow:bytesPerRow];
+		_totalTextureBytes = bytesPerRow * BufferingScanTarget::WriteAreaHeight;
 
 		// Generate pipeline.
 		id<MTLLibrary> library = [view.device newDefaultLibrary];
 		MTLRenderPipelineDescriptor *pipelineDescriptor = [[MTLRenderPipelineDescriptor alloc] init];
-		pipelineDescriptor.vertexFunction = [library newFunctionWithName:@"scanVertexMain"];
-		pipelineDescriptor.fragmentFunction = [library newFunctionWithName:@"scanFragmentMain"];
 		pipelineDescriptor.colorAttachments[0].pixelFormat = view.colorPixelFormat;
+
+		// TODO: logic somewhat more complicated than this, probably
+		pipelineDescriptor.vertexFunction = [library newFunctionWithName:@"scanVertexMain"];
+		switch(newModals->input_data_type) {
+			default:
+				pipelineDescriptor.fragmentFunction = [library newFunctionWithName:@"scanFragmentMainRGB"];
+			break;
+			case Outputs::Display::InputDataType::Luminance1:
+				pipelineDescriptor.fragmentFunction = [library newFunctionWithName:@"scanFragmentMainL1"];
+			break;
+		}
+
 		_scanPipeline = [view.device newRenderPipelineStateWithDescriptor:pipelineDescriptor error:nil];
 	}
 
diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal b/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal
index 17af486dd..f2e81d258 100644
--- a/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal	
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal	
@@ -88,10 +88,20 @@ vertex ColouredVertex scanVertexMain(	constant Uniforms &uniforms [[buffer(1)]],
 	return output;
 }
 
-fragment half4 scanFragmentMain(ColouredVertex vert [[stage_in]], texture2d<float> texture [[texture(0)]]) {
-	constexpr sampler s(coord::pixel,
-						address::clamp_to_zero,	// This really makes no difference here; anything Metal will accept will do.
-						filter::nearest);
+namespace {
+
+constexpr sampler standardSampler(	coord::pixel,
+									address::clamp_to_edge,	// Although arbitrary, stick with this address mode for compatibility all the way to MTLFeatureSet_iOS_GPUFamily1_v1.
+									filter::nearest);
 
-	return half4(texture.sample(s, vert.textureCoordinates) * 32.0f); // Multiply by 32 is _TEMPORARY TEST CODE_ [/ nonsense].
+}
+
+// MARK: - Input formst to RGB conversions.
+
+fragment half4 scanFragmentMainRGB (ColouredVertex vert [[stage_in]], texture2d<float> texture [[texture(0)]]) {
+	return half4(texture.sample(standardSampler, vert.textureCoordinates));
+}
+
+fragment half4 scanFragmentMainL1(ColouredVertex vert [[stage_in]], texture2d<float> texture [[texture(0)]]) {
+	return half4(half3(texture.sample(standardSampler, vert.textureCoordinates).r * 255.0), 1.0);
 }