diff --git a/zUtil_ForwardSim/gtShowFsim.m b/zUtil_ForwardSim/gtShowFsim.m
index 41a0c17f23fd9be3b8088c9c3df2178c28fceda2..7f9b79c52af8cf232e1926ff5b898b8cd71b9913 100644
--- a/zUtil_ForwardSim/gtShowFsim.m
+++ b/zUtil_ForwardSim/gtShowFsim.m
@@ -87,11 +87,15 @@ db_info = gtDBLoadTable([datasetname 'difspot'], 'difspotID');
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Getting fields and updating grain
-pixelsize = mean([parameters.labgeo.pixelsizeu, parameters.labgeo.pixelsizev]);
-detrefpos_pix = parameters.labgeo.detrefpos ./ pixelsize;
+if (~isfield(parameters, 'detgeo'))
+    [parameters.detgeo, parameters.labgeo] = gtGeoConvertLegacyLabgeo2Detgeo(parameters.labgeo);
+end
+
+pixelsize = mean([parameters.detgeo.pixelsizeu, parameters.detgeo.pixelsizev]);
+detrefpos_pix = parameters.detgeo.detrefpos ./ pixelsize;
 spotsCommProps = gtFwdSimGetDiffspotsCommonProperties(grain, detrefpos_pix, parameters);
 
-getradius = @(u, v) sqrt((u - parameters.labgeo.detrefu).^2 + (v - parameters.labgeo.detrefv).^2);
+getradius = @(u, v) sqrt((u - parameters.detgeo.detrefu).^2 + (v - parameters.detgeo.detrefv).^2);
 
 if strcmpi(app.fsimtype, 'allblobs')
     uvw       = grain.allblobs.detector(1).uvw;