Index: trunk/ippTools/src/regtool.c
===================================================================
--- trunk/ippTools/src/regtool.c	(revision 8661)
+++ trunk/ippTools/src/regtool.c	(revision 8711)
@@ -676,4 +676,13 @@
 
     bool status = false;
+    psString exp_type = psMetadataLookupStr(&status, config->args, "-exp_type");
+    if (!status) {
+        psError(PS_ERR_UNKNOWN, false, "failed to lookup value for -exp_type");
+        return false;
+    }
+    if (!exp_type) {
+        psError(PS_ERR_UNKNOWN, true, "-exp_type is required");
+        return false;
+    }
     psString filter = psMetadataLookupStr(&status, config->args, "-filter");
     if (!status) {
@@ -789,5 +798,5 @@
         exp->camera,
         exp->telescope,
-        exp->exp_type,
+        exp_type,
         exp->imfiles,
         filter,