Index: trunk/ppStack/src/ppStackPhotometry.c
===================================================================
--- trunk/ppStack/src/ppStackPhotometry.c	(revision 31054)
+++ trunk/ppStack/src/ppStackPhotometry.c	(revision 33702)
@@ -54,4 +54,11 @@
     }
 
+    // Add the expnum image to the photometry readout's analysis metadata so that it is available to
+    // psphotSetNFrames
+    pmReadout *photRO = pmFPAviewThisReadout(photView, photFile->fpa);
+    if (photRO && options->expRO->mask) {
+        psMetadataAddImage(photRO->analysis, PS_LIST_TAIL, "EXPNUM", PS_META_REPLACE, "EXPNUM image", options->expRO->mask);
+    }
+
     pmModelClassSetLimits(PM_MODEL_LIMITS_LAX);
     if (!psphotReadoutKnownSources(config, photView, "PSPHOT.INPUT", inSources)) {