diff --git a/newsfragments/XXX.bugfix b/newsfragments/XXX.bugfix
new file mode 100644
index 0000000000..ceef178857
--- /dev/null
+++ b/newsfragments/XXX.bugfix
@@ -0,0 +1 @@
+``dials.image_viewer``: Fix for stills experiments viewing crash introduced in #2556
diff --git a/src/dials/util/image_viewer/spotfinder_frame.py b/src/dials/util/image_viewer/spotfinder_frame.py
index c967402218..56e7304e15 100644
--- a/src/dials/util/image_viewer/spotfinder_frame.py
+++ b/src/dials/util/image_viewer/spotfinder_frame.py
@@ -263,8 +263,8 @@ def __init__(self, *args, **kwds):
                 self.viewing_stills = False
                 break
         for experiment_list in self.experiments:
-            if any(
-                exp.scan and (exp.scan.get_oscillation()[1] != 0.0)
+            if not all(
+                exp.scan and (exp.scan.get_oscillation()[1] == 0.0)
                 for exp in experiment_list
             ):
                 self.viewing_still_scans = False