diff --git a/src/main/java/bdv/AbstractSpimSource.java b/src/main/java/bdv/AbstractSpimSource.java
index 6fa30eb7..67731110 100644
--- a/src/main/java/bdv/AbstractSpimSource.java
+++ b/src/main/java/bdv/AbstractSpimSource.java
@@ -57,19 +57,19 @@
 
 public abstract class AbstractSpimSource< T extends NumericType< T > > implements Source< T >
 {
-	protected static class ImgKey
+	private static class ImgKey
 	{
-		protected final int timepoint;
+		private final int timepoint;
 
-		protected final int level;
+		private final int level;
 
-		protected final Interpolation method;
+		private final Interpolation method;
 
-		protected final ThreadGroup threadGroup;
+		private final ThreadGroup threadGroup;
 
 		private final int hashcode;
 
-		public ImgKey(
+		ImgKey(
 				final int timepoint,
 				final int level,
 				final Interpolation method,
@@ -109,37 +109,37 @@ public boolean equals( final Object obj )
 		}
 	}
 
-	protected int currentTimePointIndex;
+	private int currentTimePointIndex;
 
-	protected boolean currentTimePointIsPresent;
+	private boolean currentTimePointIsPresent;
 
-	protected final AffineTransform3D[] currentSourceTransforms;
+	private final AffineTransform3D[] currentSourceTransforms;
 
-	protected final int setupId;
+	private final int setupId;
 
-	protected final String name;
+	private final String name;
 
-	protected final List< TimePoint > timePointsOrdered;
+	private final List< TimePoint > timePointsOrdered;
 
-	protected final Map< ViewId, ViewRegistration > viewRegistrations;
+	private final Map< ViewId, ViewRegistration > viewRegistrations;
 
-	protected final Set< ViewId > missingViews;
+	private final Set< ViewId > missingViews;
 
-	protected final VoxelDimensions voxelDimensions;
+	private final VoxelDimensions voxelDimensions;
 
-	protected final int numMipmapLevels;
+	private final int numMipmapLevels;
 
-	protected final static int numInterpolationMethods = 2;
+	private final static int numInterpolationMethods = 2;
 
-	protected final static int iNearestNeighborMethod = 0;
+	private final static int iNearestNeighborMethod = 0;
 
-	protected final static int iNLinearMethod = 1;
+	private final static int iNLinearMethod = 1;
 
-	protected final InterpolatorFactory< T, RandomAccessible< T > >[] interpolatorFactories;
+	private final InterpolatorFactory< T, RandomAccessible< T > >[] interpolatorFactories;
 
-	protected final UncheckedCache< ImgKey, RandomAccessibleInterval< T > > cachedSources;
+	private final UncheckedCache< ImgKey, RandomAccessibleInterval< T > > cachedSources;
 
-	protected final UncheckedCache< ImgKey, RealRandomAccessible< T > > cachedInterpolatedSources;
+	private final UncheckedCache< ImgKey, RealRandomAccessible< T > > cachedInterpolatedSources;
 
 	@SuppressWarnings( "unchecked" )
 	public AbstractSpimSource( final AbstractSpimData< ? > spimData, final int setupId, final String name )
@@ -181,9 +181,10 @@ public AbstractSpimSource( final AbstractSpimData< ? > spimData, final int setup
 		for ( int level = 0; level < numMipmapLevels; level++ )
 			currentSourceTransforms[ level ] = new AffineTransform3D();
 
+		currentTimePointIndex = -1;
 	}
 
-	protected void loadTimepoint( final int timepointIndex )
+	void loadTimepoint( final int timepointIndex )
 	{
 		currentTimePointIndex = timepointIndex;
 		currentTimePointIsPresent = isPresent( timepointIndex );
@@ -206,9 +207,9 @@ protected void loadTimepoint( final int timepointIndex )
 		}
 	}
 
-	protected abstract AffineTransform3D[] getMipmapTransforms();
+	abstract AffineTransform3D[] getMipmapTransforms();
 
-	protected abstract RandomAccessibleInterval< T > getImage( final int timepointId, final int level );
+	abstract RandomAccessibleInterval< T > getImage( int timepointId, int level );
 
 	@Override
 	public boolean isPresent( final int t )
diff --git a/src/main/java/bdv/SpimSource.java b/src/main/java/bdv/SpimSource.java
index c8fe9d4b..526e5a53 100644
--- a/src/main/java/bdv/SpimSource.java
+++ b/src/main/java/bdv/SpimSource.java
@@ -36,7 +36,7 @@
 
 public class SpimSource< T extends NumericType< T > > extends AbstractSpimSource< T >
 {
-	protected final ViewerSetupImgLoader< T, ? > imgLoader;
+	private final ViewerSetupImgLoader< T, ? > imgLoader;
 
 	@SuppressWarnings( "unchecked" )
 	public SpimSource( final AbstractSpimData< ? > spimData, final int setup, final String name )
@@ -44,7 +44,6 @@ public SpimSource( final AbstractSpimData< ? > spimData, final int setup, final
 		super( spimData, setup, name );
 		final AbstractSequenceDescription< ?, ?, ? > seq = spimData.getSequenceDescription();
 		imgLoader = ( ViewerSetupImgLoader< T, ? > ) ( ( ViewerImgLoader ) seq.getImgLoader() ).getSetupImgLoader( setup );
-		loadTimepoint( 0 );
 	}
 
 	@Override
@@ -54,13 +53,13 @@ public T getType()
 	}
 
 	@Override
-	protected RandomAccessibleInterval< T > getImage( final int timepointId, final int level )
+	RandomAccessibleInterval< T > getImage( final int timepointId, final int level )
 	{
 		return imgLoader.getImage( timepointId, level );
 	}
 
 	@Override
-	protected AffineTransform3D[] getMipmapTransforms()
+	AffineTransform3D[] getMipmapTransforms()
 	{
 		return imgLoader.getMipmapTransforms();
 	}
diff --git a/src/main/java/bdv/VolatileSpimSource.java b/src/main/java/bdv/VolatileSpimSource.java
index 42d1d3dd..587fb130 100644
--- a/src/main/java/bdv/VolatileSpimSource.java
+++ b/src/main/java/bdv/VolatileSpimSource.java
@@ -42,9 +42,9 @@ public class VolatileSpimSource< V extends Volatile< ? > & NumericType< V > >
 		extends AbstractSpimSource< V >
 		implements MipmapOrdering
 {
-	protected final ViewerSetupImgLoader< ?, V > imgLoader;
+	private final ViewerSetupImgLoader< ?, V > imgLoader;
 
-	protected final MipmapOrdering mipmapOrdering;
+	private final MipmapOrdering mipmapOrdering;
 
 	@SuppressWarnings( "unchecked" )
 	public VolatileSpimSource( final AbstractSpimData< ? > spimData, final int setup, final String name )
@@ -56,7 +56,6 @@ public VolatileSpimSource( final AbstractSpimData< ? > spimData, final int setup
 			mipmapOrdering = ( ( MipmapOrdering ) imgLoader );
 		else
 			mipmapOrdering = new DefaultMipmapOrdering( this );
-		loadTimepoint( 0 );
 	}
 
 	@Override
@@ -66,13 +65,13 @@ public V getType()
 	}
 
 	@Override
-	protected RandomAccessibleInterval< V > getImage( final int timepointId, final int level )
+	RandomAccessibleInterval< V > getImage( final int timepointId, final int level )
 	{
 		return imgLoader.getVolatileImage( timepointId, level );
 	}
 
 	@Override
-	protected AffineTransform3D[] getMipmapTransforms()
+	AffineTransform3D[] getMipmapTransforms()
 	{
 		return imgLoader.getMipmapTransforms();
 	}