Index: trunk/ppSim/src/ppSimArguments.c
===================================================================
--- trunk/ppSim/src/ppSimArguments.c	(revision 14657)
+++ trunk/ppSim/src/ppSimArguments.c	(revision 14667)
@@ -71,6 +71,8 @@
     pmConfigFileSetsMD (config->arguments, &argc, argv, "PSPHOT.PSF", "-psf", "-psflist");
 
-    if (!config->camera) {
-        psErrorStackPrint(stderr, "A camera name must be specified using the -camera option.");
+    // only one of -camera and -file is needed
+    bool status = pmConfigFileSetsMD (config->arguments, &argc, argv, "INPUT", "-file", "-list");
+    if (!config->camera && !status) {
+        psErrorStackPrint(stderr, "A camera name (-camera NAME) or an image (-file NAME) must be specified");
         usage(argv[0], arguments, config);
     }
@@ -82,4 +84,5 @@
     psString formatName = psMetadataLookupStr(NULL, arguments, "-format"); // Name of format
     if (formatName) {
+	// XXX delay the config below until ppSimCreate?
         config->formatName = psMemIncrRefCounter(formatName);