diff --git a/rtengine/rtthumbnail.cc b/rtengine/rtthumbnail.cc
index afd8836a1..1210518d4 100644
--- a/rtengine/rtthumbnail.cc
+++ b/rtengine/rtthumbnail.cc
@@ -279,6 +279,11 @@ Thumbnail* Thumbnail::loadFromImage (const Glib::ustring& fname, int &w, int &h,
             printf ("loadFromImage: Unsupported image type \"%s\"!\n", img->getType());
         }
 
+        ProcParams paramsForAutoExp; // Dummy for constructor
+        ImProcFunctions ipf (&paramsForAutoExp, false);
+        ipf.getAutoExp (tpp->aeHistogram, tpp->aeHistCompression, 0.02, tpp->aeExposureCompensation, tpp->aeLightness, tpp->aeContrast, tpp->aeBlack, tpp->aeHighlightCompression, tpp->aeHighlightCompressionThreshold);
+        tpp->aeValid = true;
+
         if (n > 0) {
             ColorTemp cTemp;
 
@@ -923,6 +928,11 @@ Thumbnail* Thumbnail::loadFromRaw (const Glib::ustring& fname, RawMetaDataLocati
                 }
             }
         }
+        ProcParams paramsForAutoExp; // Dummy for constructor
+        ImProcFunctions ipf (&paramsForAutoExp, false);
+        ipf.getAutoExp (tpp->aeHistogram, tpp->aeHistCompression, 0.02, tpp->aeExposureCompensation, tpp->aeLightness, tpp->aeContrast, tpp->aeBlack, tpp->aeHighlightCompression, tpp->aeHighlightCompressionThreshold);
+        tpp->aeValid = true;
+
         if (ri->get_colors() == 1) {
             pixSum[0] = pixSum[1] = pixSum[2] = 1.;
             n[0] = n[1] = n[2] = 1;
@@ -993,6 +1003,13 @@ Thumbnail::Thumbnail () :
     wbEqual (-1.0),
     wbTempBias (0.0),
     aeHistCompression (3),
+    aeValid(false),
+    aeExposureCompensation(0.0),
+    aeLightness(0),
+    aeContrast(0),
+    aeBlack(0),
+    aeHighlightCompression(0),
+    aeHighlightCompressionThreshold(0),
     embProfileLength (0),
     embProfileData (nullptr),
     embProfile (nullptr),
@@ -1224,8 +1241,17 @@ IImage8* Thumbnail::processImage (const procparams::ProcParams& params, eSensorT
     int     hlcompr = params.toneCurve.hlcompr;
     int     hlcomprthresh = params.toneCurve.hlcomprthresh;
 
-    if (params.toneCurve.autoexp && aeHistogram) {
-        ipf.getAutoExp (aeHistogram, aeHistCompression, params.toneCurve.clip, expcomp, bright, contr, black, hlcompr, hlcomprthresh);
+    if (params.toneCurve.autoexp) {
+        if (aeValid) {
+            expcomp = aeExposureCompensation;
+            bright = aeLightness;
+            contr = aeContrast;
+            black = aeBlack;
+            hlcompr = aeHighlightCompression;
+            hlcomprthresh = aeHighlightCompressionThreshold;
+        } else if (aeHistogram) {
+            ipf.getAutoExp (aeHistogram, aeHistCompression, 0.02, expcomp, bright, contr, black, hlcompr, hlcomprthresh);
+        }
     }
 
     LUTf curve1 (65536);
@@ -1992,6 +2018,38 @@ bool Thumbnail::readData  (const Glib::ustring& fname)
                 aeHistCompression   = keyFile.get_integer ("LiveThumbData", "AEHistCompression");
             }
 
+            aeValid = true;
+            if (keyFile.has_key ("LiveThumbData", "AEExposureCompensation")) {
+                aeExposureCompensation = keyFile.get_double ("LiveThumbData", "AEExposureCompensation");
+            } else {
+                aeValid = false;
+            }
+            if (keyFile.has_key ("LiveThumbData", "AELightness")) {
+                aeLightness   = keyFile.get_integer ("LiveThumbData", "AELightness");
+            } else {
+                aeValid = false;
+            }
+            if (keyFile.has_key ("LiveThumbData", "AEContrast")) {
+                aeContrast   = keyFile.get_integer ("LiveThumbData", "AEContrast");
+            } else {
+                aeValid = false;
+            }
+            if (keyFile.has_key ("LiveThumbData", "AEBlack")) {
+                aeBlack   = keyFile.get_integer ("LiveThumbData", "AEBlack");
+            } else {
+                aeValid = false;
+            }
+            if (keyFile.has_key ("LiveThumbData", "AEHighlightCompression")) {
+                aeHighlightCompression   = keyFile.get_integer ("LiveThumbData", "AEHighlightCompression");
+            } else {
+                aeValid = false;
+            }
+            if (keyFile.has_key ("LiveThumbData", "AEHighlightCompressionThreshold")) {
+                aeHighlightCompressionThreshold   = keyFile.get_integer ("LiveThumbData", "AEHighlightCompressionThreshold");
+            } else {
+                aeValid = false;
+            }
+
             if (keyFile.has_key ("LiveThumbData", "RedMultiplier")) {
                 redMultiplier       = keyFile.get_double ("LiveThumbData", "RedMultiplier");
             }
@@ -2065,7 +2123,12 @@ bool Thumbnail::writeData  (const Glib::ustring& fname)
         keyFile.set_double  ("LiveThumbData", "RedAWBMul", redAWBMul);
         keyFile.set_double  ("LiveThumbData", "GreenAWBMul", greenAWBMul);
         keyFile.set_double  ("LiveThumbData", "BlueAWBMul", blueAWBMul);
-        keyFile.set_integer ("LiveThumbData", "AEHistCompression", aeHistCompression);
+        keyFile.set_double  ("LiveThumbData", "AEExposureCompensation", aeExposureCompensation);
+        keyFile.set_integer ("LiveThumbData", "AELightness", aeLightness);
+        keyFile.set_integer ("LiveThumbData", "AEContrast", aeContrast);
+        keyFile.set_integer ("LiveThumbData", "AEBlack", aeBlack);
+        keyFile.set_integer ("LiveThumbData", "AEHighlightCompression", aeHighlightCompression);
+        keyFile.set_integer ("LiveThumbData", "AEHighlightCompressionThreshold", aeHighlightCompressionThreshold);
         keyFile.set_double  ("LiveThumbData", "RedMultiplier", redMultiplier);
         keyFile.set_double  ("LiveThumbData", "GreenMultiplier", greenMultiplier);
         keyFile.set_double  ("LiveThumbData", "BlueMultiplier", blueMultiplier);
diff --git a/rtengine/rtthumbnail.h b/rtengine/rtthumbnail.h
index 558d136ee..667d8e1c9 100644
--- a/rtengine/rtthumbnail.h
+++ b/rtengine/rtthumbnail.h
@@ -50,6 +50,13 @@ class Thumbnail
     double autoWBTemp, autoWBGreen, wbEqual, wbTempBias;    // autoWBTemp and autoWBGreen are updated each time autoWB is requested and if wbEqual has been modified
     LUTu aeHistogram;
     int  aeHistCompression;
+    bool aeValid;
+    double aeExposureCompensation;
+    int aeLightness;
+    int aeContrast;
+    int aeBlack;
+    int aeHighlightCompression;
+    int aeHighlightCompressionThreshold;
     int embProfileLength;
     unsigned char* embProfileData;
     cmsHPROFILE embProfile;
@@ -100,6 +107,7 @@ public:
     bool readAEHistogram  (const Glib::ustring& fname);
     bool writeAEHistogram (const Glib::ustring& fname);
 
+    bool isAeValid() { return aeValid; };
     unsigned char* getImage8Data();  // accessor to the 8bit image if it is one, which should be the case for the "Inspector" mode.
 
     // Hombre: ... let's hope that proper template can make this cleaner
diff --git a/rtgui/thumbnail.cc b/rtgui/thumbnail.cc
index c2d23eab2..4921a2d56 100644
--- a/rtgui/thumbnail.cc
+++ b/rtgui/thumbnail.cc
@@ -854,8 +854,10 @@ void Thumbnail::_loadThumbnail(bool firstTrial)
     }
 
     if ( cfs.thumbImgType == CacheImageData::FULL_THUMBNAIL ) {
-        // load aehistogram
-        tpp->readAEHistogram (getCacheFileName ("aehistograms", ""));
+        if(!tpp->isAeValid()) {
+            // load aehistogram
+            tpp->readAEHistogram (getCacheFileName ("aehistograms", ""));
+        }
 
         // load embedded profile
         tpp->readEmbProfile (getCacheFileName ("embprofiles", ".icc"));
@@ -907,9 +909,10 @@ void Thumbnail::_saveThumbnail ()
     // save thumbnail image
     tpp->writeImage (getCacheFileName ("images", ""));
 
-    // save aehistogram
-    tpp->writeAEHistogram (getCacheFileName ("aehistograms", ""));
-
+    if(!tpp->isAeValid()) {
+        // save aehistogram
+        tpp->writeAEHistogram (getCacheFileName ("aehistograms", ""));
+    }
     // save embedded profile
     tpp->writeEmbProfile (getCacheFileName ("embprofiles", ".icc"));