diff --git a/omeroweb/webclient/templates/webclient/annotations/metadata_preview.html b/omeroweb/webclient/templates/webclient/annotations/metadata_preview.html
index 5c1d9364f0..bb1238539c 100644
--- a/omeroweb/webclient/templates/webclient/annotations/metadata_preview.html
+++ b/omeroweb/webclient/templates/webclient/annotations/metadata_preview.html
@@ -118,7 +118,7 @@
             {% if share and not share.share.isOwned %}
             OME.preview_viewport = $.WeblitzViewport($("#viewport"), "{% url 'webindex' %}{{ share.share.id }}", {'mediaroot': '{{ STATIC_URL }}' } );
             {% else %}
-            OME.preview_viewport = $.WeblitzViewport($("#viewport"), "{% url 'webindex' %}", {'mediaroot': '{{ STATIC_URL }}' } );
+            OME.preview_viewport = $.WeblitzViewport($("#viewport"), '{{ base_url }}', {'mediaroot': '{{ STATIC_URL }}' } );
             {% endif %}
 
             OME.preview_viewport.bind('imageLoad', _refresh_cb);
diff --git a/omeroweb/webclient/views.py b/omeroweb/webclient/views.py
index 2435222042..4e47536694 100755
--- a/omeroweb/webclient/views.py
+++ b/omeroweb/webclient/views.py
@@ -1792,9 +1792,9 @@ def load_metadata_preview(request, c_type, c_id, conn=None, share_id=None, **kwa
             if c["active"]:
                 act = ""
             color = c["lut"] if "lut" in c else c["color"]
-            reverse = "r" if c["inverted"] else "-r"
+            inverted = "r" if c["inverted"] else "-r"
             chs.append(
-                "%s%s|%s:%s%s$%s" % (act, i + 1, c["start"], c["end"], reverse, color)
+                "%s%s|%s:%s%s$%s" % (act, i + 1, c["start"], c["end"], inverted, color)
             )
         rdefQueries.append(
             {
@@ -1808,7 +1808,20 @@ def load_metadata_preview(request, c_type, c_id, conn=None, share_id=None, **kwa
     size_x = manager.image.getSizeX()
     size_y = manager.image.getSizeY()
 
-    context["tiledImage"] = (size_x * size_y) > (max_w * max_h)
+    base_url = reverse('webindex')
+    big_image = (size_x * size_y) > (max_w * max_h)
+    if not big_image:
+        # if we have omero_web_zarr installed and s3 data is available, we
+        # use that as data source for viewer via /zarr/render_image etc.
+        try:
+            from omero_web_zarr.views import get_zarr_s3_path
+            zarr_path = get_zarr_s3_path(conn, manager.image.id)
+            if zarr_path is not None and zarr_path.startswith("http"):
+                base_url = reverse('omero_web_zarr_index')
+        except ImportError:
+            pass
+    context["base_url"] = base_url
+    context["tiledImage"] = big_image
     context["manager"] = manager
     context["rdefsJson"] = json.dumps(rdefQueries)
     context["rdefs"] = rdefs