diff --git a/include/libcamera/internal/software_isp/debayer_params.h b/include/libcamera/internal/software_isp/debayer_params.h
index 256c7d43..2d69bd29 100644
--- a/include/libcamera/internal/software_isp/debayer_params.h
+++ b/include/libcamera/internal/software_isp/debayer_params.h
@@ -59,7 +59,7 @@ struct DebayerParams {
 	Matrix<float, 3, 3> ccm;
 	RGB<float> blackLevel;
 	float gamma;
-	double contrastExp;
+	float contrastExp;
 };
 
 } /* namespace libcamera */
diff --git a/src/ipa/simple/algorithms/adjust.cpp b/src/ipa/simple/algorithms/adjust.cpp
index a067f7b8..a8b7c5ab 100644
--- a/src/ipa/simple/algorithms/adjust.cpp
+++ b/src/ipa/simple/algorithms/adjust.cpp
@@ -34,8 +34,8 @@ int Adjust::configure(IPAContext &context,
 		      [[maybe_unused]] const IPAConfigInfo &configInfo)
 {
 	context.activeState.knobs.gamma = kDefaultGamma;
-	context.activeState.knobs.contrast = std::optional<double>();
-	context.activeState.knobs.saturation = std::optional<double>();
+	context.activeState.knobs.contrast = std::optional<float>();
+	context.activeState.knobs.saturation = std::optional<float>();
 
 	return 0;
 }
diff --git a/src/ipa/simple/algorithms/lut.cpp b/src/ipa/simple/algorithms/lut.cpp
index d8e92c61..fd442259 100644
--- a/src/ipa/simple/algorithms/lut.cpp
+++ b/src/ipa/simple/algorithms/lut.cpp
@@ -40,7 +40,7 @@ void Lut::updateGammaTable(IPAContext &context)
 	const auto gamma = 1.0 / context.activeState.knobs.gamma;
 	const auto contrast = context.activeState.knobs.contrast.value_or(1.0);
 	/* Convert 0..2 to 0..infinity; avoid actual inifinity at tan(pi/2) */
-	double contrastExp = tan(std::clamp(contrast * M_PI_4, 0.0, M_PI_2 - 0.00001));
+	float contrastExp = tan(std::clamp(contrast * M_PI_4, 0.0, M_PI_2 - 0.00001));
 
 	if (!context.gpuIspEnabled) {
 		auto &gammaTable = context.activeState.gamma.gammaTable;
diff --git a/src/ipa/simple/ipa_context.h b/src/ipa/simple/ipa_context.h
index eeade9d3..293e35b7 100644
--- a/src/ipa/simple/ipa_context.h
+++ b/src/ipa/simple/ipa_context.h
@@ -58,8 +58,8 @@ struct IPAActiveState {
 		std::array<double, kGammaLookupSize> gammaTable;
 		uint8_t blackLevel;
 		float gamma;
-		double contrast;
-		double contrastExp;
+		float contrast;
+		float contrastExp;
 	} gamma;
 
 	Matrix<float, 3, 3> combinedMatrix;
@@ -68,7 +68,7 @@ struct IPAActiveState {
 	struct {
 		float gamma;
 		/* 0..2 range, 1.0 = normal */
-		std::optional<double> contrast;
+		std::optional<float> contrast;
 		std::optional<float> saturation;
 	} knobs;
 };
@@ -87,7 +87,7 @@ struct IPAFrameContext : public FrameContext {
 	} gains;
 
 	float gamma;
-	std::optional<double> contrast;
+	std::optional<float> contrast;
 	std::optional<float> saturation;
 };