diff --git a/rtgui/batchqueue.cc b/rtgui/batchqueue.cc
index 47b9daeaf..83155f0a2 100644
--- a/rtgui/batchqueue.cc
+++ b/rtgui/batchqueue.cc
@@ -62,6 +62,18 @@ BatchQueue::~BatchQueue ()
 	delete pmenu;
 }
 
+// Reduce the max size of a thumb, since thumb is processed synchronously on adding to queue
+// leading to very long waiting when adding more images
+int BatchQueue::calcMaxThumbnailHeight() {
+    return MIN(options.maxThumbnailHeight, 200);
+}
+
+// Function for virtual override in thumbbrowser base
+int BatchQueue::getMaxThumbnailHeight() const {
+    return calcMaxThumbnailHeight();
+}
+
+
 void BatchQueue::rightClicked (ThumbBrowserEntryBase* entry) {
 
     pmenu->popup (3, this->eventTime);
@@ -163,11 +175,11 @@ void BatchQueue::loadBatchQueue( )
                     if( thumb ){
                         rtengine::ProcessingJob* job = rtengine::ProcessingJob::create(source, thumb->getType() == FT_Raw, pparams);
 
-                        int prevh = options.maxThumbnailHeight;
+                        int prevh = getMaxThumbnailHeight();
                         int prevw = prevh;
                         guint8* prev = NULL;
                         double tmpscale;
-                        rtengine::IImage8* img = thumb->processThumbImage(pparams, options.maxThumbnailHeight, tmpscale);
+                        rtengine::IImage8* img = thumb->processThumbImage(pparams, prevh, tmpscale);
                         if (img) {
                             prevw = img->getWidth();
                             prevh = img->getHeight();
diff --git a/rtgui/batchqueue.h b/rtgui/batchqueue.h
index a26080719..2cf9b6870 100644
--- a/rtgui/batchqueue.h
+++ b/rtgui/batchqueue.h
@@ -40,6 +40,7 @@ class BatchQueue  : public ThumbBrowserBase,
                     public LWButtonListener {  
 
   protected:
+    int getMaxThumbnailHeight() const;
 
     BatchQueueEntry* processing;  // holds the currently processed image
 
@@ -83,6 +84,7 @@ class BatchQueue  : public ThumbBrowserBase,
     void loadBatchQueue ();
 
     static Glib::ustring calcAutoFileNameBase (const Glib::ustring& origFileName);
+    static int calcMaxThumbnailHeight();
 };
 
 #endif
diff --git a/rtgui/filecatalog.cc b/rtgui/filecatalog.cc
index 8658b7e01..5282c1005 100644
--- a/rtgui/filecatalog.cc
+++ b/rtgui/filecatalog.cc
@@ -832,25 +832,35 @@ void FileCatalog::developRequested (std::vector<FileBrowserEntry*> tbe) {
 
     if (listener) {
     	std::vector<BatchQueueEntry*> entries;
+
+        #pragma omp parallel for ordered
         for (size_t i=0; i<tbe.size(); i++) {
             rtengine::procparams::ProcParams params = tbe[i]->thumbnail->getProcParams();
             rtengine::ProcessingJob* pjob = rtengine::ProcessingJob::create (tbe[i]->filename, tbe[i]->thumbnail->getType()==FT_Raw, params);
             double tmpscale;
-            rtengine::IImage8* img = tbe[i]->thumbnail->processThumbImage (params, options.maxThumbnailHeight, tmpscale);
+            rtengine::IImage8* img = tbe[i]->thumbnail->processThumbImage (params, BatchQueue::calcMaxThumbnailHeight(), tmpscale);
+
+            int pw, ph;
+            guint8* prev=NULL;
+
             if (img) {
-                int pw = img->getWidth ();
-                int ph = img->getHeight ();
-                guint8* prev = new guint8 [pw*ph*3];
+                pw = img->getWidth ();
+                ph = img->getHeight ();
+                prev = new guint8 [pw*ph*3];
                 memcpy (prev, img->getData (), pw*ph*3);
                 img->free();
+ 
+            } else {
+                tbe[i]->thumbnail->getThumbnailSize (pw, ph);
+            }
+
+            // processThumbImage is the processing intensive part, but adding to queue must be ordered
+            #pragma omp ordered
+            {
                 entries.push_back(new BatchQueueEntry (pjob, params, tbe[i]->filename, prev, pw, ph, tbe[i]->thumbnail));
             }
-            else {
-                int pw, ph;
-                tbe[i]->thumbnail->getThumbnailSize (pw, ph);
-                entries.push_back(new BatchQueueEntry (pjob, params, tbe[i]->filename, NULL, pw, ph, tbe[i]->thumbnail));
             }
-        }
+
         listener->addBatchQueueJobs( entries );
     }
 }
diff --git a/rtgui/thumbbrowserbase.cc b/rtgui/thumbbrowserbase.cc
index 353043e2d..01c327811 100644
--- a/rtgui/thumbbrowserbase.cc
+++ b/rtgui/thumbbrowserbase.cc
@@ -478,13 +478,13 @@ void ThumbBrowserBase::zoomChanged (bool zoomIn) {
     int optThumbSize=getCurrentThumbSize();
     if (zoomIn)
         for (i=0; i<options.thumbnailZoomRatios.size(); i++) {
-            newHeight = (int)(options.thumbnailZoomRatios[i] * options.maxThumbnailHeight);
+            newHeight = (int)(options.thumbnailZoomRatios[i] * getMaxThumbnailHeight());
             if (newHeight > optThumbSize)
                 break;
         }
     else
         for (i=options.thumbnailZoomRatios.size()-1; i>=0; i--) {
-            newHeight = (int)(options.thumbnailZoomRatios[i] * options.maxThumbnailHeight);
+            newHeight = (int)(options.thumbnailZoomRatios[i] * getMaxThumbnailHeight());
             if (newHeight < optThumbSize)
                 break;
         }
diff --git a/rtgui/thumbbrowserbase.h b/rtgui/thumbbrowserbase.h
index 3095ee5d4..92fa20237 100644
--- a/rtgui/thumbbrowserbase.h
+++ b/rtgui/thumbbrowserbase.h
@@ -22,6 +22,7 @@
 #include <gtkmm.h>
 #include <thumbbrowserentrybase.h>
 #include <set>
+#include <options.h>
 
 /*
  * Class handling the list of ThumbBrowserEntry objects and their position in it's allocated space
@@ -52,6 +53,7 @@ class ThumbBrowserBase  :  public Gtk::VBox {
     };
 
   protected:
+    virtual int getMaxThumbnailHeight() const { return options.maxThumbnailHeight; }  // Differs between batch and file
 
     Internal internal;
     Gtk::HScrollbar hscroll;