Color me (ugh) a little disappointed. I knew that an achromatic telescope would display some chromatic aberration on brighter subjects, but I really had no idea it would be this bad.

The two images here were taken with my new C6-R (6" f/8 achromat refractor), Rebel XSi at ISO 800. Guiding was done with an Orion ST 80 with a Starshoot Autoguider.

I don't know if my focus was slightly off, or if the chromatic aberration really is this bad on this scope, but these are unacceptable with those purple-ringed stars.

Research needed...