diff --git a/rtengine/camconst.json b/rtengine/camconst.json
index d75b46a70..fa291adf8 100755
--- a/rtengine/camconst.json
+++ b/rtengine/camconst.json
@@ -822,7 +822,7 @@ Quality X: unknown, ie we knowing to little about the camera properties to know
     { // Quality B, does not work with 12bit files 
          "make_model": "Nikon D750",
          "dcraw_matrix": [ 9020,-2890,-715,-4535,12436,2348,-934,1919,7086 ], // adobe dcp d65 DNGv8.7
-         "ranges": { "black": 600, "white": 16300 } // attention.. BL/WL values are for 14bit files, has to be BL150/WL4070 for 12bit files. WL typical 16383 set to 16300 for safety
+         "ranges": { "black": -600, "white": 16300 } // attention.. BL/WL values are for 14bit files, has to be BL150/WL4070 for 12bit files. WL typical 16383 set to 16300 for safety
     },
 
    { // quality B, lacks WL measures at intermediate ISOs (160-250-320 ..) and measures at long exposures with LongExposureNoiseReduction 
@@ -1138,38 +1138,37 @@ Quality X: unknown, ie we knowing to little about the camera properties to know
                     ]
                   }
     },
-
-   { // Quality c, corrections for frame size, black level not declared properly
-        "make_model": "Sigma SD14",
-        "dcraw_matrix": [ 16411,-4764,-2383,8110,2603,-645,3135,3878,1984 ], // experimental inverted icc wp12 - build with BL=15
-      //  "dcraw_matrix": [ 13804,-4156,-1896,6917,1909,-431,2768,2989,1741 ], // experimental inverted icc wp10 - build with BL=15
-        "ranges": { "black": 15, "white": 4080 },// peripheral black stripes give BL around 37 
-        "raw_crop": [ 18, 12, 2652, 1768 ]
-    },
-
-    { // Quality c, correction for frame width
-        "make_model": "Sigma SD1",
-        "dcraw_matrix": [ 5270,42,-814,3737,5506,124,1112,9714,4510 ], // experimental from icm 1.04477,-0.74838,1.01617, -0.54028,2.52690,-3.83257, 0.54869,-0.69556,3.73746
-        "ranges": { "black": 16, "white": 4070 },// BL is 16 or 31, should be measured at the horizontal black stripe at the top 
-        "raw_crop": [ 12, 52, -110, -8 ]
-    },
-    { // Quality C, correction for frame width, color matrix investigated ..
-        "make_model": "Sigma SD1 Merrill",
-        "dcraw_matrix": [ 7211,-1577,-769,4996,3428,440,2717,7117,4699 ], // experimental inverted icc cloudy8140 d65
-      //  "dcraw_matrix": [ 5666,139,-892,3780,5428,270,1366,9757,4526 ], // experimental inverted icc sunny8161
-      // "dcraw_matrix": [ 10288,-2449,-1718,8976,1868,-1608,7011,5039,-249 ], // experimental inverted icc tungsten8130 wp11
-      // "dcraw_matrix": [ 5864,679,-1491,2963,7635,-919,-640,13738,2790 ], // experimental inverted icc sunny8160
-      //  "dcraw_matrix": [ 14032,-2231,-1016,-5263,14816,170,-112,183,9113 ], //  hardcoded 
-        "ranges": { "black": 16, "white": 4070 }, // BL is 16 or 31, should be measured at the horizontal black stripe at the top 
-        "raw_crop": [ 12, 52, -110, -8 ] // for small size all numbers/2 
-    },
-    { // Quality C, correction for frame width, color matrix guessed ..
-        "make_model": [ "Sigma DP1 Merrill", "Sigma DP2 Merrill", "Sigma DP3 Merrill" ],
-        "dcraw_matrix": [ 7211,-1577,-769,4996,3428,440,2717,7117,4699 ], // copy fron SD1 Merrill icc cloudy8140 d65
-        "ranges": { "black": 16, "white": 4070 }, // BL is 16 or 31, should be measured at the horizontal black stripe at the bottom 
-        "raw_crop": [ 12, 0, -110, -62 ] // for small size all numbers/2 
-    },
-
+
+   { // Quality c, corrections for frame size, black level not declared properly
+        "make_model": "Sigma SD14",
+        "dcraw_matrix": [ 16411,-4764,-2383,8110,2603,-645,3135,3878,1984 ], // experimental inverted icc wp12 - build with BL=15
+      //  "dcraw_matrix": [ 13804,-4156,-1896,6917,1909,-431,2768,2989,1741 ], // experimental inverted icc wp10 - build with BL=15
+        "ranges": { "black": 15, "white": 4080 },// peripheral black stripes give BL around 37
+        "raw_crop": [ 18, 12, 2652, 1768 ]
+    },
+
+    { // Quality c, correction for frame width
+        "make_model": "Sigma SD1",
+        "dcraw_matrix": [ 5270,42,-814,3737,5506,124,1112,9714,4510 ], // experimental from icm 1.04477,-0.74838,1.01617, -0.54028,2.52690,-3.83257, 0.54869,-0.69556,3.73746
+        "ranges": { "black": 16, "white": 4070 },// BL is 16 or 31, should be measured at the horizontal black stripe at the top
+        "raw_crop": [ 12, 52, -110, -8 ]
+    },
+    { // Quality C, correction for frame width, color matrix investigated ..
+        "make_model": "Sigma SD1 Merrill",
+        "dcraw_matrix": [ 7211,-1577,-769,4996,3428,440,2717,7117,4699 ], // experimental inverted icc cloudy8140 d65
+      //  "dcraw_matrix": [ 5666,139,-892,3780,5428,270,1366,9757,4526 ], // experimental inverted icc sunny8161
+      // "dcraw_matrix": [ 10288,-2449,-1718,8976,1868,-1608,7011,5039,-249 ], // experimental inverted icc tungsten8130 wp11
+      // "dcraw_matrix": [ 5864,679,-1491,2963,7635,-919,-640,13738,2790 ], // experimental inverted icc sunny8160
+      //  "dcraw_matrix": [ 14032,-2231,-1016,-5263,14816,170,-112,183,9113 ], //  hardcoded
+        "ranges": { "black": 16, "white": 4070 }, // BL is 16 or 31, should be measured at the horizontal black stripe at the top
+        "raw_crop": [ 12, 52, -110, -8 ] // for small size all numbers/2
+    },
+    { // Quality C, correction for frame width, color matrix guessed ..
+        "make_model": [ "Sigma DP1 Merrill", "Sigma DP2 Merrill", "Sigma DP3 Merrill" ],
+        "dcraw_matrix": [ 7211,-1577,-769,4996,3428,440,2717,7117,4699 ], // copy fron SD1 Merrill icc cloudy8140 d65
+        "ranges": { "black": 16, "white": 4070 }, // BL is 16 or 31, should be measured at the horizontal black stripe at the bottom
+        "raw_crop": [ 12, 0, -110, -62 ] // for small size all numbers/2
+    },
 
     { // Quality A, correction for color matrix from Colin Walker's d50 to dng d65
         "make_model": "Sony NEX-C3",