diff --git a/src/ipa/ipu3/algorithms/agc.cpp b/src/ipa/ipu3/algorithms/agc.cpp
index 08deff0c..8e07c89e 100644
--- a/src/ipa/ipu3/algorithms/agc.cpp
+++ b/src/ipa/ipu3/algorithms/agc.cpp
@@ -228,12 +228,15 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 	double analogueGain = frameContext.sensor.gain;
 	utils::Duration effectiveExposureValue = exposureTime * analogueGain;
 
+	/* \todo Plumb in the lux value. Requires a lux algo + tuning */
+	double lux = 400;
+
 	utils::Duration shutterTime;
 	double aGain, dGain;
 	std::tie(shutterTime, aGain, dGain) =
 		calculateNewEv(context.activeState.agc.constraintMode,
 			       context.activeState.agc.exposureMode, hist_,
-			       effectiveExposureValue);
+			       effectiveExposureValue, lux);
 
 	LOG(IPU3Agc, Debug)
 		<< "Divided up shutter, analogue gain and digital gain are "
diff --git a/src/ipa/libipa/agc.cpp b/src/ipa/libipa/agc.cpp
index af57a571..bcb036e6 100644
--- a/src/ipa/libipa/agc.cpp
+++ b/src/ipa/libipa/agc.cpp
@@ -110,7 +110,7 @@ static constexpr double kDefaultRelativeLuminanceTarget = 0.16;
  */
 
 MeanLuminanceAgc::MeanLuminanceAgc()
-	: frameCount_(0), filteredExposure_(0s), relativeLuminanceTarget_(0)
+	: frameCount_(0), filteredExposure_(0s)
 {
 }
 
@@ -120,8 +120,12 @@ MeanLuminanceAgc::MeanLuminanceAgc()
  */
 void MeanLuminanceAgc::parseRelativeLuminanceTarget(const YamlObject &tuningData)
 {
-	relativeLuminanceTarget_ =
-		tuningData["relativeLuminanceTarget"].get<double>(kDefaultRelativeLuminanceTarget);
+	int ret = relativeLuminanceTarget_.readYaml(tuningData["relativeLuminanceTarget"]);
+	if (ret == 0)
+		return;
+
+	std::vector<FPoint> points = { { 0, kDefaultRelativeLuminanceTarget } };
+	relativeLuminanceTarget_ = Pwl(points);
 }
 
 /**
@@ -378,6 +382,7 @@ int MeanLuminanceAgc::parseExposureModes(const YamlObject &tuningData)
 /**
  * \brief Estimate the initial gain needed to achieve a relative luminance
  *        target
+ * \param[in] lux The lux value at which to sample the luminance target pwl
  *
  * To account for non-linearity caused by saturation, the value needs to be
  * estimated in an iterative process, as multiplying by a gain will not increase
@@ -385,9 +390,10 @@ int MeanLuminanceAgc::parseExposureModes(const YamlObject &tuningData)
  *
  * \return The calculated initial gain
  */
-double MeanLuminanceAgc::estimateInitialGain()
+double MeanLuminanceAgc::estimateInitialGain(double lux)
 {
-	double yTarget = relativeLuminanceTarget_;
+	double yTarget =
+		relativeLuminanceTarget_.eval(relativeLuminanceTarget_.domain().clamp(lux));
 	double yGain = 1.0;
 
 	for (unsigned int i = 0; i < 8; i++) {
@@ -476,6 +482,7 @@ utils::Duration MeanLuminanceAgc::filterExposure(utils::Duration exposureValue)
  *	      the calculated gain
  * \param[in] effectiveExposureValue The EV applied to the frame from which the
  *	      statistics in use derive
+ * \param[in] lux The lux value at which to sample the luminance target pwl
  *
  * Calculate a new exposure value to try to obtain the target. The calculated
  * exposure value is filtered to prevent rapid changes from frame to frame, and
@@ -487,7 +494,8 @@ std::tuple<utils::Duration, double, double>
 MeanLuminanceAgc::calculateNewEv(uint32_t constraintModeIndex,
 				 uint32_t exposureModeIndex,
 				 const Histogram &yHist,
-				 utils::Duration effectiveExposureValue)
+				 utils::Duration effectiveExposureValue,
+				 double lux)
 {
 	/*
 	 * The pipeline handler should validate that we have received an allowed
@@ -496,7 +504,7 @@ MeanLuminanceAgc::calculateNewEv(uint32_t constraintModeIndex,
 	std::shared_ptr<ExposureModeHelper> exposureModeHelper =
 		exposureModeHelpers_.at(exposureModeIndex);
 
-	double gain = estimateInitialGain();
+	double gain = estimateInitialGain(lux);
 	gain = constraintClampGain(constraintModeIndex, yHist, gain);
 
 	/*
diff --git a/src/ipa/libipa/agc.h b/src/ipa/libipa/agc.h
index 902a359a..f187dbc8 100644
--- a/src/ipa/libipa/agc.h
+++ b/src/ipa/libipa/agc.h
@@ -16,6 +16,7 @@
 
 #include "exposure_mode_helper.h"
 #include "histogram.h"
+#include "pwl.h"
 
 namespace libcamera {
 
@@ -59,18 +60,18 @@ public:
 	}
 
 	virtual double estimateLuminance(const double gain) = 0;
-	double estimateInitialGain();
+	double estimateInitialGain(double lux);
 	double constraintClampGain(uint32_t constraintModeIndex,
 				   const Histogram &hist,
 				   double gain);
 	utils::Duration filterExposure(utils::Duration exposureValue);
 	std::tuple<utils::Duration, double, double>
 	calculateNewEv(uint32_t constraintModeIndex, uint32_t exposureModeIndex,
-		       const Histogram &yHist, utils::Duration effectiveExposureValue);
+		       const Histogram &yHist, utils::Duration effectiveExposureValue, double lux);
 private:
 	uint64_t frameCount_;
 	utils::Duration filteredExposure_;
-	double relativeLuminanceTarget_;
+	Pwl relativeLuminanceTarget_;
 
 	std::map<int32_t, std::vector<AgcConstraint>> constraintModes_;
 	std::map<int32_t, std::shared_ptr<ExposureModeHelper>> exposureModeHelpers_;
diff --git a/src/ipa/rkisp1/algorithms/agc.cpp b/src/ipa/rkisp1/algorithms/agc.cpp
index 1dfc4aaa..a1b6eb39 100644
--- a/src/ipa/rkisp1/algorithms/agc.cpp
+++ b/src/ipa/rkisp1/algorithms/agc.cpp
@@ -389,12 +389,15 @@ void Agc::process(IPAContext &context, [[maybe_unused]] const uint32_t frame,
 	double analogueGain = frameContext.sensor.gain;
 	utils::Duration effectiveExposureValue = exposureTime * analogueGain;
 
+	/* \todo Plumb in the lux value. Requires a lux algo + tuning */
+	double lux = 400;
+
 	utils::Duration shutterTime;
 	double aGain, dGain;
 	std::tie(shutterTime, aGain, dGain) =
 		calculateNewEv(context.activeState.agc.constraintMode,
 			       context.activeState.agc.exposureMode, hist_,
-			       effectiveExposureValue);
+			       effectiveExposureValue, lux);
 
 	LOG(RkISP1Agc, Debug)
 		<< "Divided up shutter, analogue gain and digital gain are "