diff --git a/.gitignore b/.gitignore
index 1a5c508..cfa1b7a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@ run.py
 __pycache__/
 *.py[cod]
 .idea/
+*.idea/*
 # C extensions
 *.so
 
diff --git a/nd2reader/__init__.py b/nd2reader/__init__.py
index d53beeb..db04f99 100644
--- a/nd2reader/__init__.py
+++ b/nd2reader/__init__.py
@@ -30,11 +30,11 @@ class Nd2(BaseNd2):
                         if image.is_valid:
                             yield image
 
-    def image_sets(self, field_of_view, timepoints=None, channels=None, z_levels=None):
+    def image_sets(self, field_of_view, time_indices=None, channels=None, z_levels=None):
         """
         Gets all the images for a given field of view and
         """
-        timepoint_set = xrange(self.timepoint_count) if timepoints is None else timepoints
+        timepoint_set = xrange(self.timepoint_count) if time_indices is None else time_indices
         channel_set = [channel.name for channel in self.channels] if channels is None else channels
         z_level_set = xrange(self.z_level_count) if z_levels is None else z_levels
 
diff --git a/nd2reader/service/__init__.py b/nd2reader/service/__init__.py
index fdd0f65..8798392 100644
--- a/nd2reader/service/__init__.py
+++ b/nd2reader/service/__init__.py
@@ -69,7 +69,12 @@ class BaseNd2(object):
         NIS Elements can figure it out, but we haven't found it yet.
 
         """
-        return sum(self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx'][''][0]['pItemValid'])
+        try:
+            valid_fovs = self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx'][''][0]['pItemValid']
+        except KeyError:
+            # if nothing was deleted, there won't be a 0 key
+            valid_fovs = self._metadata['ImageMetadata']['SLxExperiment']['ppNextLevelEx']['']['pItemValid']
+        return sum(valid_fovs)
 
     @property
     def channel_count(self):