diff --git a/nabu/resources/dataset_analyzer.py b/nabu/resources/dataset_analyzer.py
index 365160e88b24b68d7d9d586e5419a0c0a7d0234b..914f47a01d5f16af170f51507ebb5bdca5844f29 100644
--- a/nabu/resources/dataset_analyzer.py
+++ b/nabu/resources/dataset_analyzer.py
@@ -409,8 +409,13 @@ class HDF5DatasetAnalyzer(DatasetAnalyzer):
         slices: list of slice
             A list where each item is a slice.
         """
-        check_supported(what, ["projections", "flats", "darks"], "image type")
-        images = getattr(self, what)  # dict
+        name_to_attr = {
+            "projections": self.projections,
+            "flats": self.raw_flats,
+            "darks": self.raw_darks,
+        }
+        check_supported(what, name_to_attr.keys(), "image type")
+        images = name_to_attr[what]  # dict
         # we can't directly use set() on slice() object (unhashable). Use tuples
         slices = set()
         for du in get_compacted_dataslices(images).values():