diff --git a/gtsam/geometry/CameraSet.h b/gtsam/geometry/CameraSet.h
index dd58f8e69..ecdc7c007 100644
--- a/gtsam/geometry/CameraSet.h
+++ b/gtsam/geometry/CameraSet.h
@@ -141,18 +141,18 @@ public:
     return z;
   }
 
-  /// Calculate vector of re-projection errors
+  /// Calculate vector [z-project2(point)] of re-projection errors
   Vector reprojectionError(const Point3& point, const std::vector<Z>& measured,
       boost::optional<FBlocks&> Fs = boost::none, //
       boost::optional<Matrix&> E = boost::none) const {
-    return ErrorVector(project2(point, Fs, E), measured);
+    return ErrorVector(measured, project2(point, Fs, E));
   }
 
-  /// Calculate vector of re-projection errors, from point at infinity
+  /// Calculate vector [z-project2(point)] of re-projection errors, from point at infinity
   // TODO: take Unit3 instead
   Vector reprojectionErrorAtInfinity(const Point3& point,
       const std::vector<Z>& measured) const {
-    return ErrorVector(projectAtInfinity(point), measured);
+    return ErrorVector(measured, projectAtInfinity(point));
   }
 
   /**
diff --git a/gtsam/geometry/tests/testCameraSet.cpp b/gtsam/geometry/tests/testCameraSet.cpp
index 05ffc275c..f34809ae6 100644
--- a/gtsam/geometry/tests/testCameraSet.cpp
+++ b/gtsam/geometry/tests/testCameraSet.cpp
@@ -75,7 +75,7 @@ TEST(CameraSet, Pinhole) {
   Vector4 expectedV;
 
   // reprojectionError
-  expectedV << -1, -2, -3, -4;
+  expectedV << 1, 2, 3, 4;
   Vector actualV = set.reprojectionError(p, measured);
   EXPECT(assert_equal(expectedV, actualV));
 
diff --git a/gtsam/geometry/tests/testPinholeSet.cpp b/gtsam/geometry/tests/testPinholeSet.cpp
index 1e5426f33..a8e43003d 100644
--- a/gtsam/geometry/tests/testPinholeSet.cpp
+++ b/gtsam/geometry/tests/testPinholeSet.cpp
@@ -115,7 +115,7 @@ TEST(PinholeSet, Pinhole) {
   Vector4 expectedV;
 
   // reprojectionError
-  expectedV << -1, -2, -3, -4;
+  expectedV << 1, 2, 3, 4;
   Vector actualV = set.reprojectionError(p, measured);
   EXPECT(assert_equal(expectedV, actualV));