F6.3 focal reducer?

Hi All:

I have some questions, just what exactly are these reducers doing to the SCT's wavefront and lightpath? Do they add chromatic aberration or reduce it? Do they slightly overcorrect or undercorrect the optics? Is their primary purpose to reduce spherical aberration, similar to the HST's corrective surgury? I have a 12" LX200 with undercorrected optics and way too much chromatic aberration, Damian Peach had this same problem with his 12" LX200, but to a lesser degree. What I'm really asking is will one of these reducers improve the view or make it even worse?

Thanks, clear skies! Dan

Dan Petersen said:

Hi All:

I have some questions, just what exactly are these reducers doing to the SCT's wavefront and lightpath? Do they add chromatic aberration or reduce it? Do they slightly overcorrect or undercorrect the optics? Is their primary purpose to reduce spherical aberration, similar to the HST's corrective surgury? I have a 12" LX200 with undercorrected optics and way too much chromatic aberration, Damian Peach had this same problem with his 12" LX200, but to a lesser degree. What I'm really asking is will one of these reducers improve the view or make it even worse?

Thanks, clear skies! Dan

They do nothing (major, anyway) as far as chromatic aberration. If they did anything, they might add a little color, but I've never noticed such a thing. Nor do they mess with the wavefront error.

If you're seeing severe color with your LX200, I'd look to things like differential refraction, cooldown, and eyepieces/barlows.