<p class=”wp-dark-mode-bg-image”>A test would be to take images with the telescope rotated to different angles (but with the camera orientated the same relative to the horizon). If it is atmospheric refraction the red and blue areas will always be top and bottom relative to the horizon. If it is the telescope, they will move to different angles relative to the horizon
<p class=”wp-dark-mode-bg-image”>Cheers<br class=”wp-dark-mode-bg-image”>
Robin
Good point. I wish I had thought of that.