From 8d0755eddc6d3aa02de4b39154ca40edde7865c9 Mon Sep 17 00:00:00 2001
From: rom9 <4711834+rom9@users.noreply.github.com>
Date: Tue, 11 Jun 2019 22:50:36 +0200
Subject: [PATCH] Raised default master exponent from 1.0 to 2.0, to get a
 reasonable contrast right from the start.

---
 rtengine/filmnegativeproc.cc | 4 ++--
 rtengine/procparams.cc       | 6 +++---
 rtgui/filmnegative.cc        | 8 ++++----
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/rtengine/filmnegativeproc.cc b/rtengine/filmnegativeproc.cc
index 5766fbf1e..db98fdf02 100644
--- a/rtengine/filmnegativeproc.cc
+++ b/rtengine/filmnegativeproc.cc
@@ -117,9 +117,9 @@ bool RawImageSource::getFilmNegativeExponents (Coord2D spotA, Coord2D spotB, int
     // compared to the ratio in the reference channel (green)
     for(int ch=0; ch<3; ch++)
         if(ch==1)
-            newExps[ch] = 1.f;  // Green is the reference channel
+            newExps[ch] = 2.f;  // Green is the reference channel
         else
-            newExps[ch] = CLAMP(logBase(clearVals[ch] / denseVals[ch], denseGreenRatio), 0.3f, 3.f);
+            newExps[ch] = CLAMP(2.f * logBase(clearVals[ch] / denseVals[ch], denseGreenRatio), 0.3f, 6.f);
 
     if (settings->verbose)
         printf("New exponents:  R=%g G=%g B=%g\n", newExps[0], newExps[1], newExps[2]);
diff --git a/rtengine/procparams.cc b/rtengine/procparams.cc
index 9780255da..bb5c86494 100644
--- a/rtengine/procparams.cc
+++ b/rtengine/procparams.cc
@@ -2737,9 +2737,9 @@ bool MetaDataParams::operator!=(const MetaDataParams &other) const
 
 FilmNegativeParams::FilmNegativeParams() :
     enabled(false),
-    redExp(1.36),
-    greenExp(1.0),
-    blueExp(0.86)
+    redExp(2.72),
+    greenExp(2.0),
+    blueExp(1.72)
 {
 }
 
diff --git a/rtgui/filmnegative.cc b/rtgui/filmnegative.cc
index 2af69677f..8f1fb5610 100644
--- a/rtgui/filmnegative.cc
+++ b/rtgui/filmnegative.cc
@@ -34,7 +34,7 @@ FilmNegative::FilmNegative () : FoldableToolPanel(this, "filmnegative", M("TP_FI
 {
 
     auto mkExponentAdjuster = [this](Glib::ustring label, double defaultVal) {
-        Adjuster *adj = Gtk::manage(new Adjuster (label, 0.3, 5, 0.001, defaultVal)); //exponent
+        Adjuster *adj = Gtk::manage(new Adjuster (label, 0.3, 6, 0.001, defaultVal)); //exponent
         adj->setAdjusterListener (this);
     
         if (adj->delay < options.adjusterMaxDelay) {
@@ -45,9 +45,9 @@ FilmNegative::FilmNegative () : FoldableToolPanel(this, "filmnegative", M("TP_FI
         return adj;
     };
 
-    redExp   = mkExponentAdjuster(M("TP_FILMNEGATIVE_RED"), 1.36);
-    greenExp = mkExponentAdjuster(M("TP_FILMNEGATIVE_GREEN"), 1.0);
-    blueExp  = mkExponentAdjuster(M("TP_FILMNEGATIVE_BLUE"), 0.86);
+    redExp   = mkExponentAdjuster(M("TP_FILMNEGATIVE_RED"), 2.72);
+    greenExp = mkExponentAdjuster(M("TP_FILMNEGATIVE_GREEN"), 2.0);
+    blueExp  = mkExponentAdjuster(M("TP_FILMNEGATIVE_BLUE"), 1.72);
 
     redRatio = redExp->getValue() / greenExp->getValue();
     blueRatio = blueExp->getValue() / greenExp->getValue();