Grant, thanks. It may be that tilt here is reducing evenness of focus, but no end of playing with tilt does nothing to the unevenness of illumination. It isn’t even as though there is predictable gradient across the FoV, it seems there are areas of the FoV which have minimal gradient but these areas are not big enough to take the whole disc of the Sun and I’m not using a Barlow. I’ve just been looking and the B1200 is over £1000. Looking at Chris Hookers images in Ha with his newly acquired Acuter Pheonic 40 solarscope (https://britastro.org/observations/observation.php?id=20250509_220342_3acfea1c341b631f) he has no gradient, and I’d suggest potentially even better contrast than I can achieve. I am having to stop myself just clicking buy now Rother Valley Optic’s website (£999).
James