To achieve the brightest image projected by the Cosmos 4K SE, please try the following methods:

1.  Adjust Brightness to 100%.

2. For optimal brightness and image quality, use the projector in a dark room or environment.

3. Adjust the projection size to ensure it is within the recommended range for optimal brightness.

If the above solutions cannot solve your issue, please contact Nebula Customer Support at support@seenebula.com for further assistance.