Baader coma corrector - quick first impressions.

[GazOC]

I finally had the chance to use a secondhand Baader coma corrector I recently bought (cheers Tom) for my 14" f4.5 Dob. Tested 2 eyepieces with the corrector, a GSO 30mm 70 deg, a Moonfish 30mm 80 deg and a 21mm Hyperion. The different eyepieces have to placed specific distances away from the corrector an spacers and provided to achieve this and can also be bought separately. Eyepieces using the corrector don't seem to require any further in-focus than without it.

In the hour or so I had to test the kit, the corrector improved two cheap widefields from finder eyepieces at f4.5 to at least being usable for 'proper' observations, the coma normally present from 60% or so out was dealt with well but the astigmatism in these eyepieces at this focal ratio still obviously affected the views. The Hyperion doesn't show too much coma in my Dob until the last 10% of the field but the corrector sharpened up the view pretty much right to the edge, it'll be interesting to see how the 24mm version fares.

I only had time for a quick test tonight but first impressions seem to be that the cheaper eyepieces are improved but still no where near perfect but in the Hyperion the corrector really shone.