diff --git a/nerfstudio/viewer/app/src/modules/SidePanel/CameraPanel/CameraPanel.jsx b/nerfstudio/viewer/app/src/modules/SidePanel/CameraPanel/CameraPanel.jsx
index b71266d4a..6a741d156 100644
--- a/nerfstudio/viewer/app/src/modules/SidePanel/CameraPanel/CameraPanel.jsx
+++ b/nerfstudio/viewer/app/src/modules/SidePanel/CameraPanel/CameraPanel.jsx
@@ -612,6 +612,11 @@ export default function CameraPanel(props) {
 
     sceneTree.delete(['Camera Path', 'Cameras']); // delete old cameras, which is important
     if (cameras.length < 1) {
+      dispatch({
+        type: 'write',
+        path: 'renderingState/camera_choice',
+        data: 'Main Camera',
+      });
       camera_render_helper.set_visibility(false);
     } else {
       camera_render_helper.set_visibility(true);
@@ -625,7 +630,7 @@ export default function CameraPanel(props) {
       labelDiv.className = 'label';
       labelDiv.textContent = camera.properties.get('NAME');
       labelDiv.style.color = 'black';
-      labelDiv.style.backgroundColor = "rgba(255, 255, 255, 0.61)";
+      labelDiv.style.backgroundColor = 'rgba(255, 255, 255, 0.61)';
       labelDiv.style.backdropFilter = 'blur(5px)';
       labelDiv.style.padding = '6px';
       labelDiv.style.borderRadius = '6px';
diff --git a/nerfstudio/viewer/server/utils.py b/nerfstudio/viewer/server/utils.py
index 92ccc0ef7..6d13f9378 100644
--- a/nerfstudio/viewer/server/utils.py
+++ b/nerfstudio/viewer/server/utils.py
@@ -54,6 +54,9 @@ def three_js_perspective_camera_focal_length(fov: float, image_height: int):
         fov: the field of view of the camera in degrees.
         image_height: the height of the image in pixels.
     """
+    if fov is None:
+        print("Warning: fov is None, using default value")
+        return 50
     pp_h = image_height / 2.0
     focal_length = pp_h / np.tan(fov * (np.pi / 180.0) / 2.0)
     return focal_length