diff --git a/rtdata/languages/default b/rtdata/languages/default
index 5c29e97d9..c4ae579b4 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -2759,8 +2759,9 @@ TP_LOCALLAB_MASKCOM_TOOLNAME;Common Color Mask  - 13
 TP_LOCALLAB_MASKCOM_TOOLTIP;A tool in its own right.\nCan be used to adjust the image appearance (chrominance, luminance, contrast) and texture as a function of Scope.
 TP_LOCALLAB_MASKCURVE_TOOLTIP;The 3 curves are set to 1 (maximum) by default:\nC=f(C) the chroma varies according to the chrominance. You can decrease the chroma to improve the selection. By setting this curve close to zero (with a low value of C  to activate the curve) you can desaturate the background in Inverse mode.\nL=f(L) the luminance varies according to the luminance, so you can decrease the brightness to improve the selection.\nL and C = f(H) luminance and chroma vary with hue, so you can decrease luminance and chroma to improve selection
 TP_LOCALLAB_MASKH;Hue curve
-TP_LOCALLAB_MASKLCTHR;Threshold luminance mask highlights
-TP_LOCALLAB_MASKLCTHRLOW;Threshold luminance mask shadows
+TP_LOCALLAB_MASKLC_TOOLTIP;Allows you to modulate the denoise according to the mask;\n if the mask is very dark - below the threshold 'dark' - denoise will be increased.\n if the mask is clear - above the threshold 'light' - denoise will be almost cancelled.\n between the two, denoise will be maintained at the settings without mask.
+TP_LOCALLAB_MASKLCTHR;Threshold luminance mask "light"
+TP_LOCALLAB_MASKLCTHRLOW;Threshold luminance mask "dark"
 TP_LOCALLAB_MASK_TOOLTIP;You can enable multiple masks for a tool by activating another tool and using only the mask (set the tool sliders to 0 ).\n\nYou can also duplicate the RT-spot and place it close to the first spot. The small variations in the spot references allows you to make fine adjustments.  
 TP_LOCALLAB_MED;Medium
 TP_LOCALLAB_MEDIAN;Median Low
diff --git a/rtengine/procparams.cc b/rtengine/procparams.cc
index cc80f582e..567dff805 100644
--- a/rtengine/procparams.cc
+++ b/rtengine/procparams.cc
@@ -3308,8 +3308,8 @@ LocallabParams::LocallabSpot::LocallabSpot() :
     blurMethod("norm"),
     medMethod("33"),
     usemask(false),
-    levelthr(40),
-    levelthrlow(20),
+    levelthr(50.),
+    levelthrlow(25.),
     activlum(true),
     noiselumf(0.),
     noiselumf0(0.),
diff --git a/rtgui/locallabtools.cc b/rtgui/locallabtools.cc
index e2bd7728d..c55ecf817 100644
--- a/rtgui/locallabtools.cc
+++ b/rtgui/locallabtools.cc
@@ -5762,8 +5762,8 @@ LocallabBlur::LocallabBlur():
     wavshapeden(static_cast<FlatCurveEditor*>(LocalcurveEditorwavden->addCurve(CT_Flat, "", nullptr, false, false))),
     expdenoise1(Gtk::manage(new MyExpander(false, M("TP_LOCALLAB_DENOI1_EXP")))),
     usemask(Gtk::manage(new Gtk::CheckButton(M("TP_LOCALLAB_USEMASK")))),
-    levelthr(Gtk::manage(new Adjuster(M("TP_LOCALLAB_MASKLCTHR"), 0., 100., 1., 40.))),
-    levelthrlow(Gtk::manage(new Adjuster(M("TP_LOCALLAB_MASKLCTHRLOW"), 0., 100., 1., 20.))),
+    levelthr(Gtk::manage(new Adjuster(M("TP_LOCALLAB_MASKLCTHR"), 0., 100., 1., 50.))),
+    levelthrlow(Gtk::manage(new Adjuster(M("TP_LOCALLAB_MASKLCTHRLOW"), 0., 100., 1., 25.))),
     noiselumf0(Gtk::manage(new Adjuster(M("TP_LOCALLAB_NOISELUMFINEZERO"), MINCHRO, MAXCHRO, 0.01, 0.))),
     noiselumf(Gtk::manage(new Adjuster(M("TP_LOCALLAB_NOISELUMFINE"), MINCHRO, MAXCHRO, 0.01, 0.))),
     noiselumf2(Gtk::manage(new Adjuster(M("TP_LOCALLAB_NOISELUMFINETWO"), MINCHRO, MAXCHRO, 0.01, 0.))),
@@ -6165,7 +6165,7 @@ void LocallabBlur::updateAdviceTooltips(const bool showTooltips)
         lapmaskbl->set_tooltip_text(M("TP_LOCALLAB_LAPRAD1_TOOLTIP"));
         csThresholdblur->set_tooltip_text(M("TP_LOCALLAB_WAVEMASK_LEVEL_TOOLTIP"));
         sensiden->set_tooltip_text(M("TP_LOCALLAB_SENSI_TOOLTIP"));
-
+        expdenoise1->set_tooltip_markup(M("TP_LOCALLAB_MASKLC_TOOLTIP"));
     } else {
         
         expblnoise->set_tooltip_markup("");
@@ -6217,6 +6217,7 @@ void LocallabBlur::updateAdviceTooltips(const bool showTooltips)
         csThresholdblur->set_tooltip_text("");
 //        wavhue->setTooltip("");
         sensiden->set_tooltip_text("");
+        expdenoise1->set_tooltip_markup("");
 
     }
 }