Stupid Q.

[borispider]

So I guess it's safe to assume that if I get a 4-5" f/10-12 scope/lens from
Istar it would be better than a mass commercial product like my C4R?

I live in a condo so long refractors are a nogo

Then I guess I would have to upgrade to a cg5 or bigger mount and grab'n'go
will be out too.

[Watcher3]

I wouldn't think of getting rid of the C4-R for another 4" F/10. The Celestrons are generally pretty good, and if you have a good example, you're probably not far from the ISTAR level of quality. If you could hang onto the C4-R for grab n' go use, and add a larger scope, I would consider the 5" F/12 Super Achro a worthwhile addition. Better yet, a 6" F/8. Both are doable on a CG-5 although it may take a Hargreaves strut to help. I, myself, am interested in an IQ45 mount from iOptron. It's a physically bigger mount than a CG-5, but light weight compared to an Atlas or CGEM. That would be great for up to maybe a 6" F/10, which is only 300mm longer than an F/8, and about the same length as the 5" F/12. They're big, to be sure, compared to a C4-R, but not quite the 6" F/12 or F/15's on a CGE yard cannons.

Joe

[gord]

I mentioned this over on CN before as well, but an EQ5 is capable of carrying the 5 & 6" shorter FL scopes (1500mm FL and less). This is especially true if you keep the weight of the tube down. It's actually easy to get the tube weight up pretty high, pretty fast.

The EQ5 even did a pretty good job with my current tube, in somewhat "hybrid" form of heavy and custom pieces. I must say that since I got the new Astro-Physics tube rings and bolted on a Losmandy DUP, the weight is starting to climb.

But on your original Q, I would stick with the C4R, and look at adding a bigger scope. The 6" F10 would be my choice as a next step from the 4".

Clear skies,
-Gord

[Watcher3]

I don't know if Ales is planning on a Super Achro I or II for the F/8, but he was planning on doing the F/10 in a I and II. A Super Achro II in either focal length could be the last scope you ever need!

[borispider]

Tnx for the replies.
I was thinking of 6"f/8. A little planetary but wider field for DSO's.

[Ales - iStar Optical]

Dec 21, 2010 16:32:51 GMT -5 Watcher3 said:

I don't know if Ales is planning on a Super Achro I or II for the F/8, but he was planning on doing the F/10 in a I and II. A Super Achro II in either focal length could be the last scope you ever need!

Hello guys, we have finished first production run of the Achromatic Plus (anastigmatic doublet) in 127 f12 R30. tested exactly as expected so now we are producing 20 more of these lenses and most are already pre-ordered as of now! Im happy about that of course. Now we are working on 150 F5 R50 (the best version using most expensive glass types, a great cross-over between achro and apo) than we will do 150 F10. I would appreciate your input and let me know what aperture and what F-ratio would you like to see on the market by end of this year. Be reasonable though, even though we are now also producing 250 F11 R30 (a single unit) we would like to stay below 180mm aperture, not many guys are looking for larger refractor. But for those we can always custom design and produce pretty much ANY lens, availalbility of the glass blanks is a limiting factor. Stay in touch, write back to me at [e-mail]

[Watcher3]

Thanks for checking in Ales. Glad to hear that things are progressing well with the new designs.

Personally, I'm a little disappointed that the larger lenses aren't in big enough demand. I was really hoping that if my 6" R50 performs the way I am thinking, that I would like to make my "retirement" scope a 9" F/7.7 R50. If it would have to be a custom design, I might have to re-think things.