diff --git a/rtdata/languages/default b/rtdata/languages/default
index 41933093b..7c2ee6324 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -919,6 +919,7 @@ HISTORY_MSG_671;Local - cbdl mask L
 HISTORY_MSG_672;Local - cbdl mask CL
 HISTORY_MSG_673;Local - Use cbdl mask
 HISTORY_MSG_675;Local - TM soft radius
+HISTORY_MSG_676;Local Spot transition-differentiation
 HISTORY_MSG_CLAMPOOG;Clip out-of-gamut colors
 HISTORY_MSG_COLORTONING_LABGRID_VALUE;CT - Color correction
 HISTORY_MSG_COLORTONING_LABREGION_AB;CT - Color correction
@@ -2111,9 +2112,11 @@ TP_LOCALLAB_STYPE_TOOLTIP;You can choose between:\nSymmetrical - left handle lin
 TP_LOCALLAB_SYMSL;Symmetrical (mouse + sliders)
 TP_LOCALLAB_SYM;Symmetrical (mouse)
 TP_LOCALLAB_CURVEEDITOR_TONES_LABEL;Tone curve
-TP_LOCALLAB_TRANSIT;Transition
+TP_LOCALLAB_TRANSIT;Transition Gradient
 TP_LOCALLAB_TRANSIT_TOOLTIP;Adjust smoothness of transition between affected and unaffected areas.
 TP_LOCALLAB_TRANSITVALUE;Transition value
+TP_LOCALLAB_TRANSITGRAD;Transition differentiation XY
+TP_LOCALLAB_TRANSITGRAD_TOOLTIP;Changes the transition of the abscissa to that of the ordinate 
 TP_LOCALLAB_TRANSITWEAK;Transition weakening
 TP_LOCALLAB_TRANSITWEAK_TOOLTIP;Adjust weakening : change smoothness process - 1 linear - 2 parabolic - 3 cubic  
 TP_LOCALLAB_VIBRANCE;Vibrance
diff --git a/rtengine/iplocallab.cc b/rtengine/iplocallab.cc
index 12f38d9b8..e8aeaedbf 100644
--- a/rtengine/iplocallab.cc
+++ b/rtengine/iplocallab.cc
@@ -101,44 +101,60 @@ void calcGammaLut(double gamma, double ts, LUTf &gammaLut) {
     }
 }
 
-float calcLocalFactor(const float lox, const float loy, const float lcx, const float dx, const float lcy, const float dy, const float ach)
+float calcLocalFactor(const float lox, const float loy, const float lcx, const float dx, const float lcy, const float dy, const float ach, const float gradient)
 {
 //elipse x2/a2 + y2/b2=1
 //transition elipsoidal
 //x==>lox y==>loy
 // a==> dx  b==>dy
-
+//printf("grad=%f", gradient);
+    float eps = 0.0001f;
     float kelip = dx / dy;
     float belip = sqrt((rtengine::SQR((lox - lcx) / kelip) + rtengine::SQR(loy - lcy)));    //determine position ellipse ==> a and b
+    if(belip == 0.f) {
+        belip = eps;
+    }
+    //gradient allows differenciation between transition x and y
+    float rapy = fabs((loy - lcy) / belip);
     float aelip = belip * kelip;
     float degrad = aelip / dx;
+    float gradreal = gradient * rapy + 1.f;
     float ap = rtengine::RT_PI_F / (1.f - ach);
     float bp = rtengine::RT_PI_F - ap;
-    return 0.5f * (1.f + xcosf(degrad * ap + bp));  //trigo cos transition
-
+    float retreal = pow(0.5f * (1.f + xcosf(degrad * ap + bp)), rtengine::SQR(gradreal));
+    return retreal;  //trigo cos transition
 }
-float calcLocalFactorrect(const float lox, const float loy, const float lcx, const float dx, const float lcy, const float dy, const float ach)
+
+float calcLocalFactorrect(const float lox, const float loy, const float lcx, const float dx, const float lcy, const float dy, const float ach, const float gradient)
 {
     float eps = 0.0001f;
     float krap = fabs(dx / dy);
     float kx = (lox - lcx);
     float ky = (loy - lcy);
     float ref = 0.f;
+    //gradient allows differenciation between transition x and y
 
     if (fabs(kx / (ky + eps)) < krap) {
         ref = sqrt(rtengine::SQR(dy) * (1.f + rtengine::SQR(kx / (ky + eps))));
     } else {
         ref = sqrt(rtengine::SQR(dx) * (1.f + rtengine::SQR(ky / (kx + eps))));
     }
-
+ 
     float rad = sqrt(rtengine::SQR(kx) + rtengine::SQR(ky));
+    if(rad == 0.f) {
+        rad = eps;
+    }
+    float rapy = fabs((loy - lcy) / rad);
+    float gradreal = gradient * rapy + 1.f;
+    
     float coef = rad / ref;
     float ac = 1.f / (ach - 1.f);
     float fact = ac * (coef - 1.f);
-    return fact;
+    return pow(fact, rtengine::SQR(gradreal));
 
 }
 
+
 }
 
 namespace rtengine
@@ -210,6 +226,7 @@ struct local_params {
     double stren;
     int trans;
     float transweak;
+    float transgrad;
     int dehaze;
     bool inv;
     bool invex;
@@ -519,6 +536,7 @@ static void calcLocalParams(int sp, int oW, int oH, const LocallabParams& locall
     float blurSH = (float) locallab.spots.at(sp).blurSHde;
     int local_transit = locallab.spots.at(sp).transit;
     float local_transitweak = (float)locallab.spots.at(sp).transitweak;
+    float local_transitgrad = (float)locallab.spots.at(sp).transitgrad;
     float radius = (float) locallab.spots.at(sp).radius;
     double sharradius = ((double) locallab.spots.at(sp).sharradius);
     sharradius = CLIP42_35(sharradius);
@@ -625,6 +643,7 @@ static void calcLocalParams(int sp, int oW, int oH, const LocallabParams& locall
 
     lp.trans = local_transit;
     lp.transweak = local_transitweak;
+    lp.transgrad = local_transitgrad;
     lp.rad = radius;
     lp.stren = strength;
     lp.sensbn = local_sensibn;
@@ -710,8 +729,6 @@ static void calcLocalParams(int sp, int oW, int oH, const LocallabParams& locall
     lp.senshs = local_sensihs;
 }
 
-
-
 static void calcTransitionrect(const float lox, const float loy, const float ach, const local_params& lp, int &zone, float &localFactor)
 {
     zone = 0;
@@ -721,7 +738,7 @@ static void calcTransitionrect(const float lox, const float loy, const float ach
             zone = 2;
         } else {
             zone = 1;
-            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lx, lp.yc, lp.ly, ach);
+            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lx, lp.yc, lp.ly, ach, lp.transgrad);
             localFactor = pow(localFactor, lp.transweak);
         }
 
@@ -730,7 +747,7 @@ static void calcTransitionrect(const float lox, const float loy, const float ach
             zone = 2;
         } else {
             zone = 1;
-            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lx, lp.yc, lp.lyT, ach);
+            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lx, lp.yc, lp.lyT, ach, lp.transgrad);
             localFactor = pow(localFactor, lp.transweak);
         }
 
@@ -740,7 +757,7 @@ static void calcTransitionrect(const float lox, const float loy, const float ach
             zone = 2;
         } else {
             zone = 1;
-            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lxL, lp.yc, lp.lyT, ach);
+            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lxL, lp.yc, lp.lyT, ach, lp.transgrad);
             localFactor = pow(localFactor, lp.transweak);
         }
 
@@ -749,7 +766,7 @@ static void calcTransitionrect(const float lox, const float loy, const float ach
             zone = 2;
         } else {
             zone = 1;
-            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lxL, lp.yc, lp.ly, ach);
+            localFactor = calcLocalFactorrect(lox, loy, lp.xc, lp.lxL, lp.yc, lp.ly, ach, lp.transgrad);
             localFactor = pow(localFactor, lp.transweak);
         }
 
@@ -758,7 +775,6 @@ static void calcTransitionrect(const float lox, const float loy, const float ach
 }
 
 
-
 static void calcTransition(const float lox, const float loy, const float ach, const local_params& lp, int &zone, float &localFactor)
 {
     // returns the zone (0 = outside selection, 1 = transition zone between outside and inside selection, 2 = inside selection)
@@ -774,7 +790,7 @@ static void calcTransition(const float lox, const float loy, const float ach, co
             zone = (zoneVal > 1.f && ((SQR((lox - lp.xc) / (lp.lx)) + SQR((loy - lp.yc) / (lp.ly))) < 1.f)) ? 1 : 0;
 
             if (zone == 1) {
-                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lx, lp.yc, lp.ly, ach), lp.transweak);
+                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lx, lp.yc, lp.ly, ach, lp.transgrad), lp.transweak);
             }
         }
     } else if (lox >= lp.xc && lox < lp.xc + lp.lx && loy < lp.yc && loy > lp.yc - lp.lyT) {
@@ -785,7 +801,7 @@ static void calcTransition(const float lox, const float loy, const float ach, co
             zone = (zoneVal > 1.f && ((SQR((lox - lp.xc) / (lp.lx)) + SQR((loy - lp.yc) / (lp.lyT))) < 1.f)) ? 1 : 0;
 
             if (zone == 1) {
-                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lx, lp.yc, lp.lyT, ach), lp.transweak);
+                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lx, lp.yc, lp.lyT, ach, lp.transgrad), lp.transweak);
             }
         }
     } else if (lox < lp.xc && lox > lp.xc - lp.lxL && loy <= lp.yc && loy > lp.yc - lp.lyT) {
@@ -796,7 +812,7 @@ static void calcTransition(const float lox, const float loy, const float ach, co
             zone = (zoneVal > 1.f && ((SQR((lox - lp.xc) / (lp.lxL)) + SQR((loy - lp.yc) / (lp.lyT))) < 1.f)) ? 1 : 0;
 
             if (zone == 1) {
-                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lxL, lp.yc, lp.lyT, ach), lp.transweak);
+                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lxL, lp.yc, lp.lyT, ach, lp.transgrad), lp.transweak);
             }
         }
     } else if (lox < lp.xc && lox > lp.xc - lp.lxL && loy > lp.yc && loy < lp.yc + lp.ly) {
@@ -807,7 +823,7 @@ static void calcTransition(const float lox, const float loy, const float ach, co
             zone = (zoneVal > 1.f && ((SQR((lox - lp.xc) / (lp.lxL)) + SQR((loy - lp.yc) / (lp.ly))) < 1.f)) ? 1 : 0;
 
             if (zone == 1) {
-                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lxL, lp.yc, lp.ly, ach), lp.transweak);
+                localFactor = pow(calcLocalFactor(lox, loy, lp.xc, lp.lxL, lp.yc, lp.ly, ach, lp.transgrad), lp.transweak);
             }
         }
     }
diff --git a/rtengine/procevents.h b/rtengine/procevents.h
index 621585a6a..ed848ce39 100644
--- a/rtengine/procevents.h
+++ b/rtengine/procevents.h
@@ -702,6 +702,7 @@ enum ProcEventCode {
     EvLocallabEnacbMask = 672,
     EvlocallabshowmaskcbMethod = 673,
     Evlocallabsoftradiustm = 674,
+    EvLocallabSpotTransitgrad = 675,
     NUMOFEVENTS
 };
 
diff --git a/rtengine/procparams.cc b/rtengine/procparams.cc
index e97b30777..2f0b39f0c 100644
--- a/rtengine/procparams.cc
+++ b/rtengine/procparams.cc
@@ -2358,6 +2358,7 @@ LocallabParams::LocallabSpot::LocallabSpot() :
     iter(2.0),
     balan(1.0),
     transitweak(1.0),
+    transitgrad(0.0),
     avoid(false),
     // Color & Light
     expcolor(false),
@@ -2554,6 +2555,7 @@ bool LocallabParams::LocallabSpot::operator ==(const LocallabSpot& other) const
         && iter == other.iter
         && balan == other.balan
         && transitweak == other.transitweak
+        && transitgrad == other.transitgrad
         && avoid == other.avoid
         // Color & Light
         && expcolor == other.expcolor
@@ -3706,6 +3708,7 @@ int ProcParams::save(const Glib::ustring& fname, const Glib::ustring& fname2, bo
                 saveToKeyfile(!pedited || pedited->locallab.spots.at(i).iter, "Locallab", "Iter_" + std::to_string(i), spot.iter, keyFile);
                 saveToKeyfile(!pedited || pedited->locallab.spots.at(i).balan, "Locallab", "Balan_" + std::to_string(i), spot.balan, keyFile);
                 saveToKeyfile(!pedited || pedited->locallab.spots.at(i).transitweak, "Locallab", "Transitweak_" + std::to_string(i), spot.transitweak, keyFile);
+                saveToKeyfile(!pedited || pedited->locallab.spots.at(i).transitgrad, "Locallab", "Transitgrad_" + std::to_string(i), spot.transitgrad, keyFile);
                 saveToKeyfile(!pedited || pedited->locallab.spots.at(i).avoid, "Locallab", "Avoid_" + std::to_string(i), spot.avoid, keyFile);
                 // Color & Light
                 saveToKeyfile(!pedited || pedited->locallab.spots.at(i).expcolor, "Locallab", "Expcolor_" + std::to_string(i), spot.expcolor, keyFile);
@@ -4987,6 +4990,7 @@ int ProcParams::load(const Glib::ustring& fname, ParamsEdited* pedited)
                 assignFromKeyfile(keyFile, "Locallab", "Iter_" + std::to_string(i), pedited, spot.iter, spotEdited.iter);
                 assignFromKeyfile(keyFile, "Locallab", "Balan_" + std::to_string(i), pedited, spot.balan, spotEdited.balan);
                 assignFromKeyfile(keyFile, "Locallab", "Transitweak_" + std::to_string(i), pedited, spot.transitweak, spotEdited.transitweak);
+                assignFromKeyfile(keyFile, "Locallab", "Transitgrad_" + std::to_string(i), pedited, spot.transitgrad, spotEdited.transitgrad);
                 assignFromKeyfile(keyFile, "Locallab", "Avoid_" + std::to_string(i), pedited, spot.avoid, spotEdited.avoid);
                 // Color & Light
                 assignFromKeyfile(keyFile, "Locallab", "Expcolor_" + std::to_string(i), pedited, spot.expcolor, spotEdited.expcolor);
diff --git a/rtengine/procparams.h b/rtengine/procparams.h
index 6fb35ac71..e35dda5e6 100644
--- a/rtengine/procparams.h
+++ b/rtengine/procparams.h
@@ -958,6 +958,7 @@ struct LocallabParams {
         double iter;
         double balan;
         double transitweak;
+        double transitgrad;
         bool avoid;
         // Color & Light
         bool expcolor;
diff --git a/rtengine/refreshmap.cc b/rtengine/refreshmap.cc
index 9760f0aa8..6861649ec 100644
--- a/rtengine/refreshmap.cc
+++ b/rtengine/refreshmap.cc
@@ -701,7 +701,8 @@ int refreshmap[rtengine::NUMOFEVENTS] = {
     LUMINANCECURVE,     //EvlocallabHHmaskcbshape
     LUMINANCECURVE,     //EvLocallabEnacbMask
     LUMINANCECURVE,     //EvlocallabshowmaskcbMethod
-    LUMINANCECURVE     //Evlocallabsoftradiustm
+    LUMINANCECURVE,     //Evlocallabsoftradiustm
+    LUMINANCECURVE     // EvLocallabSpotTransitgrad
 };
 
 
diff --git a/rtgui/controlspotpanel.cc b/rtgui/controlspotpanel.cc
index 10a301e52..d55252be2 100644
--- a/rtgui/controlspotpanel.cc
+++ b/rtgui/controlspotpanel.cc
@@ -67,6 +67,7 @@ ControlSpotPanel::ControlSpotPanel():
     iter_(Gtk::manage(new Adjuster(M("TP_LOCALLAB_PROXI"), 0.2, 10.0, 0.1, 2.0))),
     balan_(Gtk::manage(new Adjuster(M("TP_LOCALLAB_BALAN"), 0.2, 2.5, 0.1, 1.0, Gtk::manage(new RTImage("rawtherapee-logo-16.png")), Gtk::manage(new RTImage("circle-white-small.png"))))),
     transitweak_(Gtk::manage(new Adjuster(M("TP_LOCALLAB_TRANSITWEAK"), 0.5, 8.0, 0.1, 1.0))),
+    transitgrad_(Gtk::manage(new Adjuster(M("TP_LOCALLAB_TRANSITGRAD"), -1.0, 1.0, 0.01, 0.0))),
 
     avoid_(Gtk::manage(new Gtk::CheckButton(M("TP_LOCALLAB_AVOID")))),
 
@@ -241,11 +242,14 @@ ControlSpotPanel::ControlSpotPanel():
     ToolParamBlock* const transitBox = Gtk::manage(new ToolParamBlock());
     if(showtooltip) transit_->set_tooltip_text(M("TP_LOCALLAB_TRANSIT_TOOLTIP"));
     if(showtooltip) transitweak_->set_tooltip_text(M("TP_LOCALLAB_TRANSITWEAK_TOOLTIP"));
+    if(showtooltip) transitgrad_->set_tooltip_text(M("TP_LOCALLAB_TRANSITGRAD_TOOLTIP"));
     transit_->setAdjusterListener(this);
     transitweak_->setAdjusterListener(this);
+    transitgrad_->setAdjusterListener(this);
 
     transitBox->pack_start(*transit_);
     transitBox->pack_start(*transitweak_);
+    transitBox->pack_start(*transitgrad_);
     transitFrame->add(*transitBox);
     pack_start(*transitFrame);
     
@@ -563,6 +567,7 @@ void ControlSpotPanel::load_ControlSpot_param()
     iter_->setValue((double)row[spots_.iter]);
     balan_->setValue((double)row[spots_.balan]);
     transitweak_->setValue((double)row[spots_.transitweak]);
+    transitgrad_->setValue((double)row[spots_.transitgrad]);
     avoid_->set_active(row[spots_.avoid]);
 }
 
@@ -984,6 +989,14 @@ void ControlSpotPanel::adjusterChanged(Adjuster* a, double newval)
         }
     }
 
+    if (a == transitgrad_) {
+        row[spots_.transitgrad] = transitgrad_->getValue();
+
+        if (listener) {
+            listener->panelChanged(EvLocallabSpotTransitgrad, transitgrad_->getTextValue());
+        }
+    }
+
 }
 
 void ControlSpotPanel::avoidChanged()
@@ -1050,6 +1063,7 @@ void ControlSpotPanel::disableParamlistener(bool cond)
     iter_->block(cond);
     balan_->block(cond);
     transitweak_->block(cond);
+    transitgrad_->block(cond);
     avoidConn_.block(cond);
 }
 
@@ -1076,6 +1090,7 @@ void ControlSpotPanel::setParamEditable(bool cond)
     iter_->set_sensitive(cond);
     balan_->set_sensitive(cond);
     transitweak_->set_sensitive(cond);
+    transitgrad_->set_sensitive(cond);
     avoid_->set_sensitive(cond);
 }
 
@@ -1708,6 +1723,7 @@ ControlSpotPanel::SpotRow* ControlSpotPanel::getSpot(const int id)
             r->iter = row[spots_.iter];
             r->balan = row[spots_.balan];
             r->transitweak = row[spots_.transitweak];
+            r->transitgrad = row[spots_.transitgrad];
             r->avoid = row[spots_.avoid];
 
             return r;
@@ -1833,6 +1849,7 @@ void ControlSpotPanel::addControlSpot(SpotRow* newSpot)
     row[spots_.iter] = newSpot->iter;
     row[spots_.balan] = newSpot->balan;
     row[spots_.transitweak] = newSpot->transitweak;
+    row[spots_.transitgrad] = newSpot->transitgrad;
     row[spots_.avoid] = newSpot->avoid;
     updateParamVisibility();
     disableParamlistener(false);
@@ -1877,6 +1894,7 @@ int ControlSpotPanel::updateControlSpot(SpotRow* spot)
             row[spots_.iter] = spot->iter;
             row[spots_.balan] = spot->balan;
             row[spots_.transitweak] = spot->transitweak;
+            row[spots_.transitgrad] = spot->transitgrad;
             row[spots_.avoid] = spot->avoid;
 
             updateControlSpotCurve(row);
@@ -1967,6 +1985,7 @@ ControlSpotPanel::SpotEdited* ControlSpotPanel::getEditedStates()
     se->iter = iter_->getEditedState();
     se->balan = balan_->getEditedState();
     se->transitweak = transitweak_->getEditedState();
+    se->transitgrad = transitgrad_->getEditedState();
     se->avoid = !avoid_->get_inconsistent();
 
     return se;
@@ -2035,6 +2054,7 @@ void ControlSpotPanel::setEditedStates(SpotEdited* se)
     iter_->setEditedState(se->iter ? Edited : UnEdited);
     balan_->setEditedState(se->balan ? Edited : UnEdited);
     transitweak_->setEditedState(se->transitweak ? Edited : UnEdited);
+    transitgrad_->setEditedState(se->transitgrad ? Edited : UnEdited);
     avoid_->set_inconsistent(multiImage && !se->avoid);
 
     // Update Control Spot GUI according to widgets edited states
@@ -2079,6 +2099,7 @@ void ControlSpotPanel::setDefaults(const rtengine::procparams::ProcParams * defP
     iter_->setDefault(defSpot->iter);
     balan_->setDefault(defSpot->balan);
     transitweak_->setDefault(defSpot->transitweak);
+    transitgrad_->setDefault(defSpot->transitgrad);
 
     // Set default edited states for adjusters
     if (!pedited) {
@@ -2097,6 +2118,7 @@ void ControlSpotPanel::setDefaults(const rtengine::procparams::ProcParams * defP
         iter_->setDefaultEditedState(Irrelevant);
         balan_->setDefaultEditedState(Irrelevant);
         transitweak_->setDefaultEditedState(Irrelevant);
+        transitgrad_->setDefaultEditedState(Irrelevant);
     } else {
         const LocallabParamsEdited::LocallabSpotEdited* defSpotState = new LocallabParamsEdited::LocallabSpotEdited(true);
 
@@ -2119,6 +2141,7 @@ void ControlSpotPanel::setDefaults(const rtengine::procparams::ProcParams * defP
         iter_->setDefaultEditedState(defSpotState->iter ? Edited : UnEdited);
         balan_->setDefaultEditedState(defSpotState->balan ? Edited : UnEdited);
         transitweak_->setDefaultEditedState(defSpotState->transitweak ? Edited : UnEdited);
+        transitgrad_->setDefaultEditedState(defSpotState->transitgrad ? Edited : UnEdited);
     }
 }
 
@@ -2142,6 +2165,7 @@ void ControlSpotPanel::setBatchMode(bool batchMode)
     iter_->showEditedCB();
     balan_->showEditedCB();
     transitweak_->showEditedCB();
+    transitgrad_->showEditedCB();
 
     // Set batch mode for comboBoxText
     shape_->append(M("GENERAL_UNCHANGED"));
@@ -2180,6 +2204,7 @@ ControlSpotPanel::ControlSpots::ControlSpots()
     add(iter);
     add(balan);
     add(transitweak);
+    add(transitgrad);
     add(avoid);
 }
 
diff --git a/rtgui/controlspotpanel.h b/rtgui/controlspotpanel.h
index 3abda6d1f..d892be6ee 100644
--- a/rtgui/controlspotpanel.h
+++ b/rtgui/controlspotpanel.h
@@ -64,6 +64,7 @@ public:
         double iter;
         double balan;
         double transitweak;
+        double transitgrad;
         bool avoid;
     };
 
@@ -94,6 +95,7 @@ public:
         bool iter;
         bool balan;
         bool transitweak;
+        bool transitgrad;
         bool avoid;
     };
 
@@ -306,6 +308,7 @@ private:
         Gtk::TreeModelColumn<double> iter;
         Gtk::TreeModelColumn<double> balan;
         Gtk::TreeModelColumn<double> transitweak;
+        Gtk::TreeModelColumn<double> transitgrad;
         Gtk::TreeModelColumn<bool> avoid;
     };
 
@@ -369,6 +372,7 @@ private:
     Adjuster* const iter_;
     Adjuster* const balan_;
     Adjuster* const transitweak_;
+    Adjuster* const transitgrad_;
 
     Gtk::CheckButton* const avoid_;
     sigc::connection avoidConn_;
diff --git a/rtgui/locallab.cc b/rtgui/locallab.cc
index 7cec443b5..e670259d7 100644
--- a/rtgui/locallab.cc
+++ b/rtgui/locallab.cc
@@ -1420,6 +1420,7 @@ void Locallab::read(const ProcParams* pp, const ParamsEdited* pedited)
         r->iter = pp->locallab.spots.at(i).iter;
         r->balan = pp->locallab.spots.at(i).balan;
         r->transitweak = pp->locallab.spots.at(i).transitweak;
+        r->transitgrad = pp->locallab.spots.at(i).transitgrad;
         r->avoid = pp->locallab.spots.at(i).avoid;
 
         expsettings->addControlSpot(r);
@@ -1545,6 +1546,7 @@ void Locallab::write(ProcParams* pp, ParamsEdited* pedited)
             r->iter = newSpot->iter;
             r->balan = newSpot->balan;
             r->transitweak = newSpot->transitweak;
+            r->transitgrad = newSpot->transitgrad;
             r->avoid = newSpot->avoid;
             expsettings->addControlSpot(r);
 
@@ -1759,6 +1761,7 @@ void Locallab::write(ProcParams* pp, ParamsEdited* pedited)
             r->iter = newSpot->iter;
             r->balan = newSpot->balan;
             r->transitweak = newSpot->transitweak;
+            r->transitgrad = newSpot->transitgrad;
             r->avoid = newSpot->avoid;
             expsettings->addControlSpot(r);
 
@@ -1872,6 +1875,7 @@ void Locallab::write(ProcParams* pp, ParamsEdited* pedited)
                     pp->locallab.spots.at(pp->locallab.selspot).iter = r->iter;
                     pp->locallab.spots.at(pp->locallab.selspot).balan = r->balan;
                     pp->locallab.spots.at(pp->locallab.selspot).transitweak = r->transitweak;
+                    pp->locallab.spots.at(pp->locallab.selspot).transitgrad = r->transitgrad;
                     pp->locallab.spots.at(pp->locallab.selspot).avoid = r->avoid;
                     // Color & Light
                     pp->locallab.spots.at(pp->locallab.selspot).expcolor = expcolor->getEnabled();
@@ -2098,6 +2102,7 @@ void Locallab::write(ProcParams* pp, ParamsEdited* pedited)
                         pe->locallab.spots.at(pp->locallab.selspot).thresh = pe->locallab.spots.at(pp->locallab.selspot).thresh || se->thresh;
                         pe->locallab.spots.at(pp->locallab.selspot).iter = pe->locallab.spots.at(pp->locallab.selspot).iter || se->iter;
                         pe->locallab.spots.at(pp->locallab.selspot).transitweak = pe->locallab.spots.at(pp->locallab.selspot).transitweak || se->transitweak;
+                        pe->locallab.spots.at(pp->locallab.selspot).transitgrad = pe->locallab.spots.at(pp->locallab.selspot).transitgrad || se->transitgrad;
                         pe->locallab.spots.at(pp->locallab.selspot).balan = pe->locallab.spots.at(pp->locallab.selspot).balan || se->balan;
                         pe->locallab.spots.at(pp->locallab.selspot).avoid = pe->locallab.spots.at(pp->locallab.selspot).avoid || se->avoid;
                         // Color & Light
@@ -2300,6 +2305,7 @@ void Locallab::write(ProcParams* pp, ParamsEdited* pedited)
                         pedited->locallab.spots.at(pp->locallab.selspot).iter = pedited->locallab.spots.at(pp->locallab.selspot).iter || se->iter;
                         pedited->locallab.spots.at(pp->locallab.selspot).balan = pedited->locallab.spots.at(pp->locallab.selspot).balan || se->balan;
                         pedited->locallab.spots.at(pp->locallab.selspot).transitweak = pedited->locallab.spots.at(pp->locallab.selspot).transitweak || se->transitweak;
+                        pedited->locallab.spots.at(pp->locallab.selspot).transitgrad = pedited->locallab.spots.at(pp->locallab.selspot).transitgrad || se->transitgrad;
                         pedited->locallab.spots.at(pp->locallab.selspot).avoid = pedited->locallab.spots.at(pp->locallab.selspot).avoid || se->avoid;
                         // Color & Light
                         pedited->locallab.spots.at(pp->locallab.selspot).expcolor = pedited->locallab.spots.at(pp->locallab.selspot).expcolor || !expcolor->get_inconsistent();
@@ -5012,6 +5018,7 @@ void Locallab::updateLocallabGUI(const rtengine::procparams::ProcParams* pp, con
                 se->iter = spotState->iter;
                 se->balan = spotState->balan;
                 se->transitweak = spotState->transitweak;
+                se->transitgrad = spotState->transitgrad;
                 se->avoid = spotState->avoid;
                 expsettings->setEditedStates(se);
 
diff --git a/rtgui/paramsedited.cc b/rtgui/paramsedited.cc
index 5cf0125e1..48dea544e 100644
--- a/rtgui/paramsedited.cc
+++ b/rtgui/paramsedited.cc
@@ -948,6 +948,7 @@ void ParamsEdited::initFrom(const std::vector<rtengine::procparams::ProcParams>&
                 locallab.spots.at(j).iter = locallab.spots.at(j).iter && pSpot.iter == otherSpot.iter;
                 locallab.spots.at(j).balan = locallab.spots.at(j).balan && pSpot.balan == otherSpot.balan;
                 locallab.spots.at(j).transitweak = locallab.spots.at(j).transitweak && pSpot.transitweak == otherSpot.transitweak;
+                locallab.spots.at(j).transitgrad = locallab.spots.at(j).transitgrad && pSpot.transitgrad == otherSpot.transitgrad;
                 locallab.spots.at(j).avoid = locallab.spots.at(j).avoid && pSpot.avoid == otherSpot.avoid;
                 // Color & Light
                 locallab.spots.at(j).expcolor = locallab.spots.at(j).expcolor && pSpot.expcolor == otherSpot.expcolor;
@@ -2629,6 +2630,10 @@ void ParamsEdited::combine(rtengine::procparams::ProcParams& toEdit, const rteng
             toEdit.locallab.spots.at(i).transitweak = mods.locallab.spots.at(i).transitweak;
         }
 
+        if (locallab.spots.at(i).transitgrad) {
+            toEdit.locallab.spots.at(i).transitgrad = mods.locallab.spots.at(i).transitgrad;
+        }
+
         if (locallab.spots.at(i).avoid) {
             toEdit.locallab.spots.at(i).avoid = mods.locallab.spots.at(i).avoid;
         }
@@ -4221,6 +4226,7 @@ LocallabParamsEdited::LocallabSpotEdited::LocallabSpotEdited(bool v) :
     iter(v),
     balan(v),
     transitweak(v),
+    transitgrad(v),
     avoid(v),
     // Color & Light
     expcolor(v),
@@ -4414,6 +4420,7 @@ void LocallabParamsEdited::LocallabSpotEdited::set(bool v)
     iter = v;
     balan = v;
     transitweak = v;
+    transitgrad = v;
     avoid = v;
     // Color & Light
     expcolor = v;
diff --git a/rtgui/paramsedited.h b/rtgui/paramsedited.h
index 6636f877c..0536577f1 100644
--- a/rtgui/paramsedited.h
+++ b/rtgui/paramsedited.h
@@ -375,6 +375,7 @@ public:
         bool iter;
         bool balan;
         bool transitweak;
+        bool transitgrad;
         bool avoid;
         // Color & Light
         bool expcolor;