From 4e09fd4f212efd3e8b0606302745beb1ef42d066 Mon Sep 17 00:00:00 2001
From: rom9 <4711834+rom9@users.noreply.github.com>
Date: Fri, 28 Jun 2019 21:29:06 +0200
Subject: [PATCH] Changed master exponent default from 2.0 to 1.5; it was too
 large for high-contrast negatives. Set all sliders as log-scale, centered at
 1.0, so that reasonable values can be fine-tuned more easily.

---
 rtengine/filmnegativeproc.cc |  2 +-
 rtengine/procparams.cc       |  6 +++---
 rtgui/filmnegative.cc        | 15 ++++++---------
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/rtengine/filmnegativeproc.cc b/rtengine/filmnegativeproc.cc
index 4abe32b86..f3cca1245 100644
--- a/rtengine/filmnegativeproc.cc
+++ b/rtengine/filmnegativeproc.cc
@@ -150,7 +150,7 @@ bool rtengine::RawImageSource::getFilmNegativeExponents(Coord2D spotA, Coord2D s
         if (ch == 1) {
             newExps[ch] = 1.f;  // Green is the reference channel
         } else {
-            newExps[ch] = CLAMP(logBase(clearVals[ch] / denseVals[ch], denseGreenRatio), 0.3f, 6.f);
+            newExps[ch] = CLAMP(logBase(clearVals[ch] / denseVals[ch], denseGreenRatio), 0.3f, 4.f);
         }
     }
 
diff --git a/rtengine/procparams.cc b/rtengine/procparams.cc
index 4ed97f767..b35faca94 100644
--- a/rtengine/procparams.cc
+++ b/rtengine/procparams.cc
@@ -2736,9 +2736,9 @@ bool MetaDataParams::operator!=(const MetaDataParams &other) const
 
 FilmNegativeParams::FilmNegativeParams() :
     enabled(false),
-    redExp(2.72),
-    greenExp(2.0),
-    blueExp(1.72)
+    redExp(2.04),
+    greenExp(1.5),
+    blueExp(1.29)
 {
 }
 
diff --git a/rtgui/filmnegative.cc b/rtgui/filmnegative.cc
index 129af3034..0e6ec9e8f 100644
--- a/rtgui/filmnegative.cc
+++ b/rtgui/filmnegative.cc
@@ -30,14 +30,11 @@
 namespace
 {
 
-Adjuster* createExponentAdjuster(AdjusterListener* listener, const Glib::ustring& label, double minV, double maxV, double defaultVal, bool log)
+Adjuster* createExponentAdjuster(AdjusterListener* listener, const Glib::ustring& label, double minV, double maxV, double defaultVal)
 {
-    Adjuster* const adj = Gtk::manage(new Adjuster(label, minV, maxV, 0.001, defaultVal)); // exponent
+    Adjuster* const adj = Gtk::manage(new Adjuster(label, minV, maxV, 0.001, defaultVal));
     adj->setAdjusterListener(listener);
-
-    if (log) {
-        adj->setLogScale(10, minV, false);
-    }
+    adj->setLogScale(6, 1, true);
 
     if (adj->delay < options.adjusterMaxDelay) {
         adj->delay = options.adjusterMaxDelay;
@@ -55,9 +52,9 @@ FilmNegative::FilmNegative() :
     evFilmNegativeExponents(ProcEventMapper::getInstance()->newEvent(FIRST, "HISTORY_MSG_FILMNEGATIVE_EXPONENTS")),
     evFilmNegativeEnabled(ProcEventMapper::getInstance()->newEvent(FIRST, "HISTORY_MSG_FILMNEGATIVE_ENABLED")),
     fnp(nullptr),
-    greenExp(createExponentAdjuster(this, M("TP_FILMNEGATIVE_GREEN"), 0.3, 4, 2.0, false)),
-    redRatio(createExponentAdjuster(this, M("TP_FILMNEGATIVE_RED"), 0.3, 3, 1.36, true)),
-    blueRatio(createExponentAdjuster(this, M("TP_FILMNEGATIVE_BLUE"), 0.3, 3, 0.86, true)),
+    greenExp(createExponentAdjuster(this, M("TP_FILMNEGATIVE_GREEN"), 0.3, 4, 1.5)),
+    redRatio(createExponentAdjuster(this, M("TP_FILMNEGATIVE_RED"), 0.3, 3, 1.36)),
+    blueRatio(createExponentAdjuster(this, M("TP_FILMNEGATIVE_BLUE"), 0.3, 3, 0.86)),
     spotgrid(Gtk::manage(new Gtk::Grid())),
     spotbutton(Gtk::manage(new Gtk::ToggleButton(M("TP_FILMNEGATIVE_PICK"))))
 {