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Hello!
Oct 19, 2012 12:58:39 GMT -5
Post by Ales - iStar Optical on Oct 19, 2012 12:58:39 GMT -5
John, as per my previous message, the F15 is plenty good.. but our R30 Anastigmat will offer even better perormance at F11. We produce 127 F12 which performs as F 15,5 or so (dont have calculator on hand to give you exact figure but this is close enough). You get overall much better visual performance with R30 Anastigmats compared to ANY standard Achromatic doublet... think about it, cheers, Ales
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Oct 19, 2012 13:07:36 GMT -5
Post by Ales - iStar Optical on Oct 19, 2012 13:07:36 GMT -5
Guys, in "worse" case you can always order a top quality tubes directly from ISTAR Optical.... regards, Ales
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Oct 20, 2012 1:42:34 GMT -5
Post by johndaniel on Oct 20, 2012 1:42:34 GMT -5
OK, I will think about it. And are you saying that I will get better viewing through a 5" r30 than a 6" acro? I am trying to determine what would be the best overall lens for my - planet observing, planet imaging, overall size of OTA and cost. Thank you, JohnDaniel
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Oct 20, 2012 22:16:05 GMT -5
Post by johndaniel on Oct 20, 2012 22:16:05 GMT -5
Ales would it be possible for you to send me the exact dimensions of the 127 f/12 R30 cell and the 150 mm f/8 R30 cell. I am trying to design the necessary parts for such a cope. I would also be interested in if ISTAT has a coupling for the lens cell to the tubing. Thank you, JohnDaniel
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Hello!
Oct 20, 2012 23:04:05 GMT -5
Post by criverside on Oct 20, 2012 23:04:05 GMT -5
Hi JohnDaniel,
Since no one has answered you, I'll give you my "two cents".
First both the 5" f/12 R30 and 6" f/15 are achromats, they just use different index glass, that aside, I am waiting anxiously for test results on the R30s.
As to which you should get for the planets, depends a lot on how big a tube you are willing to handle. as for differences between a 5" and 6", at higher Magnifications and "very good seeing" conditions a side by side careful comparison might show a little improvement, but you also have a much larger tube. you may say its only a inch bigger in dia. but believe me the difference seems much greater when you're mounting it. As for tube length, even 18" longer can seem much longer!
It boils down to how big a telescope you are willing to deal with. Price wise the ISTAR 6" achros are a good value, but it is a bigger tube---good luck in your selection. Hopefully Mike H. or Ales will give their opinion. For me, I would go the 6" Maybe f/12 R30 when it comes out, the heck with the long tube but that's me!---------Craig
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Oct 21, 2012 18:59:32 GMT -5
Post by istarmullet on Oct 21, 2012 18:59:32 GMT -5
I have the 6" f15 and it is a superb scope for planets. It is indeed very long, but that is not a worry for me. There is very little color. Even a bright moon shows very little color, it's there on the limb, but it is not a detractor.
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Hello!
Oct 22, 2012 10:37:55 GMT -5
Post by Ales - iStar Optical on Oct 22, 2012 10:37:55 GMT -5
Hi John, Im still traveling abroad, I have no direct access to my design database. but I can send you exact dimensions of any scope we produce. I believe that we list the overall Length on our web site, just look at the description with each telescope. Tube diameter for 127mm is 140mm and tube diameter for 150mm scopes is 160mm. This way you can compare right away. I will gladlyl reply to any other questions after I return to my EU office and settle down a bit so give me at least two more weeks from now, thank you so much for your patience, cheers, Ales
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Hello!
Oct 22, 2012 10:40:23 GMT -5
Post by Ales - iStar Optical on Oct 22, 2012 10:40:23 GMT -5
You will still get more detail on a good night with the 6" scope but viewing via 127 R30 F12 blow most people away. They frequently tell you that they can not believe how much you can see thru scope of only 127mm of clear aperture.... talk to Mike Harden since he is testing these scopes on regular basis. cheers, Ales
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