diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm
index e64723934..924b31047 100644
--- a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
@@ -25,7 +25,7 @@ struct Uniforms {
 	simd::float3x3 fromRGB;
 	float zoom;
 	simd::float2 offset;
-	float firCoefficients[8];
+	simd::float3 firCoefficients[8];
 };
 
 constexpr size_t NumBufferedScans = 2048;
@@ -373,16 +373,33 @@ using BufferingScanTarget = Outputs::Display::BufferingScanTarget;
 		_compositionRenderPass.colorAttachments[0].loadAction = MTLLoadActionClear;
 		_compositionRenderPass.colorAttachments[0].storeAction = MTLStoreActionStore;
 
-		// TODO: set proper clear colour for S-Video.
+		// TODO: set proper clear colour for S-Video (and fragment function, below).
 
-		// TODO: work out fir coefficients, for real.
+		simd::float3 *const firCoefficients = uniforms()->firCoefficients;
 		const float cyclesPerLine = float(modals.cycles_per_line);
 		const float colourCyclesPerLine = float(modals.colour_cycle_numerator) / float(modals.colour_cycle_denominator);
-		SignalProcessing::FIRFilter filter(15, cyclesPerLine, 0.0f, 16.0f * cyclesPerLine / colourCyclesPerLine);
 
-		float *const firCoefficients = uniforms()->firCoefficients;
-		const auto calculatedCoefficients = filter.get_coefficients();
-		memcpy(firCoefficients, calculatedCoefficients.data(), calculatedCoefficients.size() * sizeof(float));
+		if(isSVideoOutput) {
+			// In S-Video, don't filter luminance.
+			for(size_t c = 0; c < 7; ++c) {
+				firCoefficients[c].x = 0.0f;
+			}
+			firCoefficients[7].x = 1.0f;
+		} else {
+			// In composite, filter luminance gently.
+			SignalProcessing::FIRFilter luminancefilter(15, cyclesPerLine, 0.0f, colourCyclesPerLine * 0.75f);
+			const auto calculatedCoefficients = luminancefilter.get_coefficients();
+			for(size_t c = 0; c < 8; ++c) {
+				firCoefficients[c].x = calculatedCoefficients[c];
+			}
+		}
+
+		// Whether S-Video or composite, apply the same relatively strong filter to colour channels.
+		SignalProcessing::FIRFilter chrominancefilter(15, cyclesPerLine, 0.0f, colourCyclesPerLine * 0.125f);
+		const auto calculatedCoefficients = chrominancefilter.get_coefficients();
+		for(size_t c = 0; c < 8; ++c) {
+			firCoefficients[c].y = firCoefficients[c].z = calculatedCoefficients[c];
+		}
 	}
 
 	// Build the output pipeline.
@@ -390,8 +407,7 @@ using BufferingScanTarget = Outputs::Display::BufferingScanTarget;
 	pipelineDescriptor.vertexFunction = [library newFunctionWithName:_isUsingCompositionPipeline ? @"lineToDisplay" : @"scanToDisplay"];
 
 	if(_isUsingCompositionPipeline) {
-		// TODO!
-		pipelineDescriptor.fragmentFunction = [library newFunctionWithName:@"convertComposite"];
+		pipelineDescriptor.fragmentFunction = [library newFunctionWithName:@"filterFragment"];
 	} else {
 		const bool isRGBOutput = modals.display_type == Outputs::Display::DisplayType::RGB;
 		pipelineDescriptor.fragmentFunction =
diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal b/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal
index 0308260d0..c4ddf11ce 100644
--- a/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal	
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/ScanTarget.metal	
@@ -33,7 +33,7 @@ struct Uniforms {
 
 	// Describes the FIR filter in use; it'll be 15 coefficients but they're
 	// symmetrical around the centre.
-	float firCoefficients[8];
+	float3 firCoefficients[8];
 };
 
 namespace {
@@ -270,8 +270,11 @@ float3 convertRed1Green1Blue1(SourceInterpolator vert, texture2d<ushort> texture
 	fragment float4 compositeSample##name(SourceInterpolator vert [[stage_in]], texture2d<pixelType> texture [[texture(0)]], constant Uniforms &uniforms [[buffer(0)]]) {	\
 		const auto colour = uniforms.fromRGB * convert##name(vert, texture);	\
 		const float2 colourSubcarrier = float2(sin(vert.colourPhase), cos(vert.colourPhase));	\
+		const float level = mix(colour.r, dot(colour.gb, colourSubcarrier), vert.colourAmplitude);	\
 		return float4(	\
-			float3(mix(colour.r, dot(colour.gb, colourSubcarrier), vert.colourAmplitude)),	\
+			level,	\
+			0.5 + 0.5*level*sin(vert.colourPhase),\
+			0.5 + 0.5*level*cos(vert.colourPhase),\
 			1.0		\
 		);	\
 	}
@@ -318,7 +321,7 @@ fragment float4 clearFragment() {
 
 // MARK: - Conversion fragment shaders
 
-fragment float4 convertComposite(CopyInterpolator vert [[stage_in]], texture2d<float> texture [[texture(0)]], constant Uniforms &uniforms [[buffer(0)]]) {
+fragment float4 filterFragment(SourceInterpolator vert [[stage_in]], texture2d<float> texture [[texture(0)]], constant Uniforms &uniforms [[buffer(0)]]) {
 	const float3 colour =
 		uniforms.firCoefficients[0] * texture.sample(standardSampler, vert.textureCoordinates - float2(7.0, 0.0)).rgb +
 		uniforms.firCoefficients[1] * texture.sample(standardSampler, vert.textureCoordinates - float2(6.0, 0.0)).rgb +
@@ -336,5 +339,5 @@ fragment float4 convertComposite(CopyInterpolator vert [[stage_in]], texture2d<f
 		uniforms.firCoefficients[1] * texture.sample(standardSampler, vert.textureCoordinates + float2(6.0, 0.0)).rgb +
 		uniforms.firCoefficients[0] * texture.sample(standardSampler, vert.textureCoordinates + float2(7.0, 0.0)).rgb;
 
-	return float4(colour, 1.0);
+	return float4(uniforms.toRGB * ((colour - float3(0.0, 0.5, 0.5)) * float3(1.0, 2.0 / vert.colourAmplitude, 2.0 / vert.colourAmplitude)), 1.0);
 }