Index: trunk/ppMerge/src/ppMergeOptions.c
===================================================================
--- trunk/ppMerge/src/ppMergeOptions.c	(revision 12733)
+++ trunk/ppMerge/src/ppMergeOptions.c	(revision 13246)
@@ -100,10 +100,13 @@
     if (!config->camera) {
         psArray *filenames = psMetadataLookupPtr(NULL, config->arguments, "INPUT"); // The input file names
-        psFits *inFile = psFitsOpen(filenames->data[0], "r"); // The FITS file to read
+        psString resolved = pmConfigConvertFilename(filenames->data[0], config, false); // Resolved file name
+        psFits *inFile = psFitsOpen(resolved, "r"); // The FITS file to read
         if (!inFile) {
-            psError(PS_ERR_IO, false, "Unable to open input file %s to determine camera.\n",
-                    (char *)filenames->data[0]);
+            psError(PS_ERR_IO, false, "Unable to open input file %s to determine camera.\n", resolved);
+            psFree(resolved);
+            psFree(config);
             exit(EXIT_FAILURE);
         }
+        psFree(resolved);
         psMetadata *header = psFitsReadHeader(NULL, inFile); // The FITS (primary) header
         psFitsClose(inFile);