WRT 204-6 vs 150 f8 R30

[rgm]

I have been emailing with Mike and I am currently waiting for his skies to clear so he can give me some test reports. We are currently looking at either the f5 or f8 versions of the 150 R30 models.

I live in central Ontario which means I live under the jet stream. I can not use much more than 200x on most nights, and sometimes 150x is all the seeing will allow. I do little planet and moon observing. My most important criteria in a scope is pin point stars images across the field of view. I am almost 60 years old and my eyes can not compensate very well to field curvature. A scope has to present a fairly flat field for me to see pin point stars across most or all the field of view.

I have a small observatory and a 1200mm scope is all I can fit in. If I am considering the 150 f8, why not look at the 204 f6?

Could you comment on what the observing experience will be like with the 204 f6. By the way, I have a Losmandy G11 mount which can handle either scope.

Thanks, Bob

[mikey cee]

Well I used to own an 8" F/13.3 that I upgraded to a 10" f/11 R30. Piggybacked on this scope is a Jaegers 6" F/8. So I know first hand what an 8" refractor is capable of compared to a 6". There isn't any comparison! In a world of it's own in so many words. But if at all possible go for the R30 version which will perform more like an F/8. Sure it costs more and will be heavier but with a new Raycorr you'll have a dirt cheap apo!! Mike

[Mike]

Bob, Mikey is right in the fact that an 8 inch has a definite light gathering edge over the 6 inch. Of course, the 8 inch is not an R30 design. It will have significantly more CA just because it's so much larger in aperture. However, CA is not much of a concern if the scope is used for what is was made for... DSOs and wide field views. I don't know if I have two 204 OTAs coming at this point or not. I have two 204 lenses now. One is sold along with one OTA that I know for sure is coming. I'm supposed to get a list soon. The complete Ares 150-5 R30 is in stock. The Asteria 150-8 R30 lens is here and its OTA is on the way. The Asteria 150-8 R30 should have significantly less CA. But obviously not as compact which I know is of concern to you. Testing will really determine which will be the best for your need based on the field of view. If the skies ever clear I have at least four scopes and two lenses that are sold but have to be tested yet. Come on! I need two nights. Is that too much to ask for? The rainy season needs to end soon or I'm going to freak out from scope withdraw.