diff --git a/src/figs/align_exernal_nanosims.fig b/src/figs/align_exernal_nanosims.fig
index 875b9ee..15f7a55 100644
Binary files a/src/figs/align_exernal_nanosims.fig and b/src/figs/align_exernal_nanosims.fig differ
diff --git a/src/fnc/align2images.m b/src/fnc/align2images.m
index 18f5b65..697c8e3 100644
--- a/src/fnc/align2images.m
+++ b/src/fnc/align2images.m
@@ -1,5 +1,6 @@
 %function [im1_out,im2_xyscale,rgb,f101]=align2images(v1,v2,im1,im2,im1_xyscale,im2_xyscale,log_flag1,log_flag2)
-function [im1_out,im2_xyscale,f101]=align2images(v1,v2,im1,im2,im1_xyscale,im2_xyscale,log_flag1,log_flag2,symb_col)
+function [im1_out,im2_xyscale,f101]=align2images(v1,v2,im1,im2,im1_vscale,im2_vscale,...
+    im1_xyscale,im2_xyscale,log_flag1,log_flag2,symb_col)
 
 N = size(v1,2);
 
@@ -60,7 +61,8 @@
 % main_GUI:Preferences->Additional Output Options
 %sc1 = find_image_scale(im1(im1>0),0,additional_settings.autoscale_quantiles, log_flag1,0);
 % autoscale image based on min/max values
-sc1 = find_image_scale(im1(im1>0),1,additional_settings.autoscale_quantiles, log_flag1,0);
+% sc1 = find_image_scale(im1(im1>0),1,additional_settings.autoscale_quantiles, log_flag1,0);
+sc1 = im1_vscale;
 
 % warp the image, using the maximum as the FillValues (usually maximum is
 % white in the BW images, which is a reasonable choice)
@@ -151,7 +153,8 @@
 % transform output images before passing them for display
 
 % first the nanosims image
-sc2 = find_image_scale(im2,0,additional_settings.autoscale_quantiles, log_flag2,0);
+%sc2 = find_image_scale(im2,0,additional_settings.autoscale_quantiles, log_flag2,0);
+sc2 = im2_vscale;
 if log_flag2
     im2 = log10(im2);
     sc2 = log10(sc2);
diff --git a/src/fnc/align2images_2points.m b/src/fnc/align2images_2points.m
index 57703d7..95b58dc 100644
--- a/src/fnc/align2images_2points.m
+++ b/src/fnc/align2images_2points.m
@@ -1,10 +1,11 @@
-function [ext5,im1_xyscale,rgb,f100]=align2images_2points(v1,v2,im1,im2,im1_xyscale,im2_xyscale,log_flag1,log_flag2,tflag)
+function [ext5,im1_xyscale,rgb,f100]=align2images_2points(v1,v2,im1,im2,im1_vscale,im2_vscale,...
+    im1_xyscale,im2_xyscale,log_flag1,log_flag2,tflag)
 
 % align im1 to im2 based on two points
 
 global additional_settings;
 
-if nargin>8
+if nargin>10
     fill_v = 1*(tflag>0);
 else
     fill_v = quantile(im1(:),additional_settings.autoscale_quantiles(1));
@@ -196,7 +197,8 @@
 rgb = zeros(size(im2,1),size(im2,2),3);
 
 im1 = ext5;
-sc1 = find_image_scale(im1(im1>0),0,additional_settings.autoscale_quantiles, log_flag1,0);
+%sc1 = find_image_scale(im1(im1>0),0,additional_settings.autoscale_quantiles, log_flag1,0);
+sc1 = im1_vscale;
 if log_flag1
     im1 = log10(im1);
     sc1 = log10(sc1);
@@ -208,7 +210,8 @@
 meanv1 = (meanv1-sc1(1))/diff(sc1);
 
 im2 = nanosimsimage;
-sc2 = find_image_scale(im2,0,additional_settings.autoscale_quantiles, log_flag2,0);
+%sc2 = find_image_scale(im2,0,additional_settings.autoscale_quantiles, log_flag2,0);
+sc2 = im2_vscale;
 if log_flag2
     im2 = log10(im2);
     sc2 = log10(sc2);
diff --git a/src/fnc/align_exernal_nanosims.m b/src/fnc/align_exernal_nanosims.m
index 284842e..ce4a19c 100644
--- a/src/fnc/align_exernal_nanosims.m
+++ b/src/fnc/align_exernal_nanosims.m
@@ -498,6 +498,11 @@ function show_alignment_Callback(hObject, eventdata, handles)
 log_flag1 = get(handles.checkbox1,'value');
 log_flag2 = get(handles.checkbox2,'value');
 
+ext_vscale = str2num([get(handles.min_ext,'String'), ...
+        ' ', get(handles.max_ext,'String')]);
+ns_vscale = str2num([get(handles.min_ns,'String'), ...
+        ' ', get(handles.max_ns,'String')]);
+    
 if hObject == handles.show_alignment4
     % set flags
     set(handles.show_alignment4,'Checked','on');
@@ -506,9 +511,10 @@ function show_alignment_Callback(hObject, eventdata, handles)
     align_type = 4;
     % align based on multiple (>4) points
     v1 = round(handles.extplist');
-    v2 = round(handles.nanosimsplist');
+    v2 = round(handles.nanosimsplist');    
     [ext_aligned, ext_aligned_xyscale, f_aligned] = ...
         align2images(v1,v2,handles.extimage,handles.nanosimsimage,...
+            ext_vscale, ns_vscale,...
             handles.extimage_xyscale,handles.nanosimsimage_xyscale,...
             log_flag1,log_flag2,handles.points_color_symbol);        
     
@@ -543,7 +549,9 @@ function show_alignment_Callback(hObject, eventdata, handles)
         s2 = size(im2,2);
     end
     [ext_aligned, ext_aligned_xyscale, rgb_aligned, f_aligned] = ...
-        align_interactively(im1,im2,s1,s2,log_flag1,log_flag2);
+        align_interactively(im1,im2,...
+        ext_vscale, ns_vscale,...
+        s1,s2,log_flag1,log_flag2);
 
 elseif hObject == handles.show_alignment2
     % set flags
@@ -575,6 +583,7 @@ function show_alignment_Callback(hObject, eventdata, handles)
     extimage_xyscale = handles.extimage_xyscale * size(im1,2)/size(handles.extimage,2);
     [ext_aligned, ext_aligned_xyscale, rgb_aligned, f_aligned] = ...
         align2images_2points(v1,v2,im1,im2,...
+            ext_vscale, ns_vscale,...
             extimage_xyscale,handles.nanosimsimage_xyscale,...
             log_flag1,log_flag2);
     
@@ -630,6 +639,10 @@ function export_aligned_external_Callback(hObject, eventdata, handles)
             % rescale it first to 0->255
             im1 = handles.ext_aligned;
             sc1 = find_image_scale(im1(im1>0),0,additional_settings.autoscale_quantiles,0,0);
+            min1 = str2num(get(handles.min_ext,'String'));
+            max1 = str2num(get(handles.max_ext,'String'));
+            if isnumeric(min1), sc1(1)=min1; end
+            if isnumeric(max1), sc1(2)=max1; end
             im1 = (im1-sc1(1))/diff(sc1);
             im1(im1<0)=0;
             im1(im1>1)=1;
@@ -800,6 +813,10 @@ function load_external_image_Callback(hObject, eventdata, handles)
         a.mag_factor_used = 1;
     end
     mag_factor_used = a.mag_factor_used;
+    if isfield(a,'vscale')
+        set(handles.min_ext,'String',num2str(a.vscale(1)));
+        set(handles.max_ext,'String',num2str(a.vscale(2)));
+    end    
 else
     im=double(imread(handles.extimagefile));
     xyscale = size(im,2);
@@ -821,6 +838,10 @@ function load_external_image_Callback(hObject, eventdata, handles)
     %global additional_settings;
     %sc=quantile(double(im(:)),additional_settings.autoscale_quantiles);
     sc = find_image_scale(double(im));
+    min1 = str2num(get(handles.min_ext,'String'));
+    max1 = str2num(get(handles.max_ext,'String'));
+    if isnumeric(min1), sc(1)=min1; end
+    if isnumeric(max1), sc(2)=max1; end
     imagesc(im,sc);
     global additional_settings;
     colormap(get_colormap(additional_settings.colormap));
@@ -872,6 +893,8 @@ function load_nanosims_image_Callback(hObject, eventdata, handles)
     image(im);
 else
     sc=vscale;
+    set(handles.min_ns,'String',num2str(vscale(1)));
+    set(handles.max_ns,'String',num2str(vscale(2)));    
     imagesc(im,sc);
     colormap(get_colormap(additional_settings.colormap));
 end
@@ -1186,6 +1209,10 @@ function update_points_Callback(hObject, eventdata, handles)
     if ~isempty(im)
         axes(ax); hold off
         sc = find_image_scale(im,0,additional_settings.autoscale_quantiles, log_flag,0);
+        min1 = str2num(get(handles.min_ext,'String'));
+        max1 = str2num(get(handles.max_ext,'String'));
+        if isnumeric(min1), sc(1)=min1; end
+        if isnumeric(max1), sc(2)=max1; end
         if size(im,3)>1
             if log_flag
                 im = log10(im);
@@ -1199,6 +1226,10 @@ function update_points_Callback(hObject, eventdata, handles)
             if log_flag
                 im = log10(im);
                 sc = log10(sc);
+                if isinf(sc(1)), sc(1)=sc(2)-3; end
+            end
+            if contains(get(hObject,'Tag'),'min_') || contains(get(hObject,'Tag'),'max_')    
+                fprintf(1,'Ext image scale set to [%.2e, %.2e]\n', sc); 
             end
             imagesc(im, sc);
             colormap(get_colormap(additional_settings.colormap));
@@ -1231,6 +1262,10 @@ function update_points_Callback(hObject, eventdata, handles)
     if ~isempty(im)
         axes(ax); hold off;
         sc = find_image_scale(im,0,additional_settings.autoscale_quantiles, log_flag,0);
+        min1 = str2num(get(handles.min_ns,'String'));
+        max1 = str2num(get(handles.max_ns,'String'));
+        if isnumeric(min1), sc(1)=min1; end
+        if isnumeric(max1), sc(2)=max1; end
         if size(im,3)>1
             if log_flag
                 im = log10(im);
@@ -1244,6 +1279,10 @@ function update_points_Callback(hObject, eventdata, handles)
             if log_flag
                 im = log10(im);
                 sc = log10(sc);
+                if isinf(sc(1)), sc(1)=sc(2)-3; end
+            end
+            if contains(get(hObject,'Tag'),'min_') || contains(get(hObject,'Tag'),'max_')
+                fprintf(1,'Nanosims image scale set to [%.2e, %.2e]\n', sc); 
             end
             imagesc(im, sc);
             colormap(get_colormap(additional_settings.colormap));
diff --git a/src/fnc/align_interactively.m b/src/fnc/align_interactively.m
index 0c1e8c8..6b59fcc 100644
--- a/src/fnc/align_interactively.m
+++ b/src/fnc/align_interactively.m
@@ -1,4 +1,5 @@
-function [im_out,im1_xyscale,rgb,f102] = align_interactively(im1,im2,im1_xyscale,im2_xyscale,log_flag1,log_flag2,tflag)
+function [im_out,im1_xyscale,rgb,f102] = align_interactively(im1,im2,im1_vscale,im2_vscale,...
+    im1_xyscale,im2_xyscale,log_flag1,log_flag2,tflag)
 
 % default output
 im_out = [];
@@ -16,10 +17,11 @@
 
 global additional_settings;
 
-if nargin>6
+if nargin>8
     fill_v = 1*(tflag>0);
 else
-    fill_v = quantile(im1(:),additional_settings.autoscale_quantiles(1));
+    %fill_v = quantile(im1(:),additional_settings.autoscale_quantiles(1));
+    fill_v = im1_vscale(1);
 end
 
 % rescale image im1 so that it matches true dimensions of im2
@@ -74,7 +76,8 @@
     fprintf(1,'ERROR: Sizes of the external and nanosims images are not in proportion.\n');
     fprintf(1,'Please zoom in the external image to correct this.\n');
 else
-    sc1 = find_image_scale(im1s(im1s>0),0,additional_settings.autoscale_quantiles, log_flag1,0);
+    %sc1 = find_image_scale(im1s(im1s>0),0,additional_settings.autoscale_quantiles, log_flag1,0);
+    sc1 = im1_vscale;
     if log_flag1
         im1s = log10(im1s);
         sc1 = log10(sc1);
@@ -83,7 +86,8 @@
     im1s(im1s<0)=0;
     im1s(im1s>1)=1;
 
-    sc2 = find_image_scale(im2s,0,additional_settings.autoscale_quantiles, log_flag2,0);
+    %sc2 = find_image_scale(im2s,0,additional_settings.autoscale_quantiles, log_flag2,0);
+    sc2 = im2_vscale;
     if log_flag2
         im2s = log10(im2s);
         sc2 = log10(sc2);
diff --git a/src/fnc/display_RGB_image.m b/src/fnc/display_RGB_image.m
index 338067f..4f29bc6 100644
--- a/src/fnc/display_RGB_image.m
+++ b/src/fnc/display_RGB_image.m
@@ -8,7 +8,7 @@
 global additional_settings;
 
 
-if ~isempty(rgb7) | ~isempty(rgb8)
+if ~isempty(rgb7) || ~isempty(rgb8)
 
     for ii=1:2
         if ii==1
@@ -17,7 +17,7 @@
         else
             rgb=rgb8;
             plotopt=opt1(8);
-        end;
+        end
         
         if plotopt
             
@@ -101,34 +101,34 @@
                         
             % export RGB image (as eps and tif)
             if(opt1(11))                
-                if(~isempty(xl) & ~isempty(yl) & ~isempty(zl))
+                if(~isempty(xl) && ~isempty(yl) && ~isempty(zl))
                     xyfile0=[xl,'-vs-',yl,'-vs-',zl];
                 else
                     if(isempty(xl))
                         xyfile0=[yl,'-vs-',zl];
-                    end;
+                    end
                     if(isempty(yl))
                         xyfile0=[xl,'-vs-',zl];
-                    end;
+                    end
                     if(isempty(zl))
                         xyfile0=[xl,'-vs-',yl];
-                    end;
-                end;
+                    end
+                end
                 if(ii==1)
                     ext='-rgb';
                     ext_cmyk = '-cmyk';
                 else
                     ext='-rgba';
                     ext_cmyk = '-cmyka';
-                end;                
+                end              
                 xyfile=convert_string_for_texoutput([xyfile0,ext]);
                 xyfile=[xyfile,'.eps'];
                 xyfile=[p.fdir,'eps',delimiter,xyfile];
                 epsdir = fileparts(xyfile);
-                if(~isdir(epsdir))
+                if(~isfolder(epsdir))
                     mkdir(epsdir);
                     fprintf(1,'Directory %s did not exist, so it was created.\n',epsdir);
-                end;
+                end
                 print_figure(mf,xyfile,additional_settings.print_factors(1));
                 outfname = mepstopdf(xyfile,'epstopdf');
                 outfname = regexprep(outfname,'\','/');
@@ -136,16 +136,16 @@
                     rgb7_fname = outfname;
                 else
                     rgb8_fname = outfname;                    
-                end;
+                end
                 xyfile=convert_string_for_texoutput([xyfile0,ext]);
                 xyfile=[xyfile, '.tif'];
                 xyfile_cmyk=convert_string_for_texoutput([xyfile0,ext_cmyk]);
                 xyfile_cmyk=[xyfile_cmyk, '.tif'];
                 tifdir=[p.fdir, 'tif'];
-                if(~isdir(tifdir))
+                if(~isfolder(tifdir))
                     mkdir(tifdir);
                     fprintf(1,'Directory %s did not exist, so it was created.\n',tifdir);
-                end;
+                end
                 xyfile=[p.fdir,'tif',delimiter,xyfile];
                 xyfile_cmyk=[p.fdir,'tif',delimiter,xyfile_cmyk];
                 Nbits = 8;
@@ -158,7 +158,8 @@
                 % also save the image as CMYK
                 outprof = iccread('USSheetfedCoated.icc'); 
                 inprof = iccread('sRGB.icm');
-                C = makecform('icc',inprof,outprof);            
+                C = makecform('icc',inprof,outprof);   
+                rgb(isnan(rgb(:)))=0; % set NaN to 0
                 cmyk = applycform(rgb, C);
                 imwrite(cmyk, xyfile_cmyk);
                 %a = 0;
diff --git a/src/lookatnanosims.m b/src/lookatnanosims.m
index b15840d..6d91812 100644
--- a/src/lookatnanosims.m
+++ b/src/lookatnanosims.m
@@ -202,6 +202,7 @@
                              % counts, and the corresponding ion count ratios,
                              % will be calculated by accumulating only the
                              % specified planes.
+LANS_version = '2024-01-18'; % Bugs in align_external_image due to autoscale fixed.
 
 % name of the external image file (empty by default)
 EXTERNAL_IMAGEFILE = '';
@@ -219,7 +220,7 @@
     fprintf(1,'Written by Lubos Polerecky <lpolerec (at) mpi-bremen.de>\n')
     fprintf(1,'(2008-2012) Max-Planck Institute for Marine Microbiology, Bremen\n')
     fprintf(1,'Updates by Lubos Polerecky <l.polerecky (at) uu.nl>\n')
-    fprintf(1,'(2013-2023) Utrecht University\n')
+    fprintf(1,'(2013-2024) Utrecht University\n')
     fprintf(1,'More info: http://nanosims.geo.uu.nl/LANS\n')
     fprintf(1,'================================================================\n')
     fprintf(1,'Enjoy your work!\n')