diff --git a/rtengine/rtthumbnail.cc b/rtengine/rtthumbnail.cc
index 2e3fdc09b..ebd0e121a 100644
--- a/rtengine/rtthumbnail.cc
+++ b/rtengine/rtthumbnail.cc
@@ -527,6 +527,7 @@ Thumbnail::~Thumbnail () {
         cmsCloseProfile(camProfile);
 }
 
+// Simple processing of RAW internal JPGs
 IImage8* Thumbnail::quickProcessImage (const procparams::ProcParams& params, int rheight, TypeInterpolation interp, double& myscale) {
 
     int rwidth;
@@ -560,6 +561,7 @@ IImage8* Thumbnail::quickProcessImage (const procparams::ProcParams& params, int
 	return img8;
 }
 
+// Full thumbnail processing, second stage if complete profile exists
 IImage8* Thumbnail::processImage (const procparams::ProcParams& params, int rheight, TypeInterpolation interp, double& myscale) {
 
     // compute WB multipliers
@@ -698,6 +700,10 @@ IImage8* Thumbnail::processImage (const procparams::ProcParams& params, int rhei
     if (params.toneCurve.autoexp && aeHistogram) 
         ipf.getAutoExp (aeHistogram, aeHistCompression, logDefGain, params.toneCurve.clip, br, bl);
 
+	// The RAW exposure is not reflected since it's done in preprocessing. If we only have e.g. the chached thumb,
+	// that is already preprocessed. So we simulate the effect here roughly my modifying the exposure accordingly
+	if (params.raw.expos!=1) br += (params.raw.expos-1.0);
+
 	float* curve1 = new float [65536];
     float* curve2 = new float [65536];
 	int* curve = new int [65536];
diff --git a/rtgui/thumbnail.cc b/rtgui/thumbnail.cc
index 13653c094..a24351431 100644
--- a/rtgui/thumbnail.cc
+++ b/rtgui/thumbnail.cc
@@ -296,10 +296,12 @@ rtengine::IImage8* Thumbnail::processThumbImage (const rtengine::procparams::Pro
 
 	if ( cfs.thumbImgType == CacheImageData::QUICK_THUMBNAIL )
 	{
+		// RAW internal thumbnail, no profile yet: just do some rotation etc.
  		image = tpp->quickProcessImage (pparams, h, rtengine::TI_Nearest, scale);
 	}
 	else
 	{
+		// Full thumbnail: apply profile
  		image = tpp->processImage (pparams, h, rtengine::TI_Bilinear, scale);
 	}