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Post by astro1959 on Mar 15, 2013 17:14:59 GMT -5
Hi all, been sometime since I was here looking forward to this raycorr accessory, from all the indications this could really be the answer to many CA with all achromats hmmm...wonder how this corrector would work say with the recent APM 6in f8 refractor that Mr Ling was the pround owner of..? From his reviews read on CN he was very impressed with the performance of this ED refractor with the raycorr this could become one so called super apo.... . Anyways I wish all the best to Ales, Mike, and all the ISTAR members and can say I'm looking forward in the near future owning a ISTAR 6in f8 R30 or even a 7incher with that raycorr I could truly say I now own my own UBERVONDER scope..!!!! best, Lance
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Post by jamesling1000 on Mar 16, 2013 4:57:34 GMT -5
hi Lance....
Nice to see your 1st post in this forum, although both of us join this club around the same time....
Hope others like you can also voice up in this forum, as even myself may run out of topics and subject to contribute in this forum to get it going.....
Hi ALL...
Yes, I am really satisfied with both the 8" F8.8 Istar and 6" APM ED APO I owned..
Both performed as per my personal requirement....
The 8" Istar is doing very well in DSO with its big aperture..... while the APM ED APO is an excellent planetary scope, although it still exhibits a small trace of CA...
What motivates me in commenting on both these 2 scopes, have also to do with customer service..... Both Ales and Markus are providing good customer service, in my personal opinion...
With regards to the raycorr subject, again we can't comment much about how well it is going to make our achro performs like what a longer FL ..., at this moment of time...
Perhaps only ISTAR themselves will know how much performance it should improve....
And my personal opinion at this point of time is that it must improve a lot, reducing the CA level by at least 80%, otherwise its not going to create a big impact in this astronomy world....
I use the following to illustrate.....
The usual std 6" F8 achro exhibits quite an considerable amount of CA...
I make the decision to test the APM ED APO when Markus reports from the test result that it is like F30...... So is like almost 4X lesser CA... So when I have the chance to test it at the moon, yes, it exhibits CA, maybe 3X to 4X lesser....
So the above simple comparison, is trying to give you an idea that the raycorr must be able to reduce the CA by 80%, then the std 6" F8 will perform like the APM ED APO... That is why I commented earlier, those who wants an achro that performs better than ED, they must go for the R35 or R30 version, then even the raycorr only improves 60% to 70% , you are not far off the target...
I am not sure does the raycorr works for my APM ED APO with a stated performance of F30 , but no harm trying it out once is available. And I still have my C6R F8 with me, to test this out and report to those who are considering getting it for non Istar scopes....
Hope Ales can give us another definite answer in another one to two months time.....with regards on the raycorr subject....
Regards
James Ling
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Post by astro59 on Mar 19, 2013 23:09:40 GMT -5
Hi James, Thanks for your reply I know how you feel when one enthusiast member reaches a finite point of thinking and creating new postings, amazing how many posts you have done...! For what it is worth thank you sir for all your postings, which I found stimulating, educational, entertaining, creative and so forth thanks again...! To keep a forum such as this needs new members to keep the thought process torch burning which I will try to interject new thoughts and ideas er gripes..? chuckle.... ;D. Myself being 30 years plus as a strictly visual observer, and have had many fine instruments including a 7in f9 star-fire, Quantum 8 ota and many others. Through out my journey of studying the heavens I can attest to a fine instrument created with heart and soul, and the rewards of those special memorable nights. Which I belive is the reason why many of us are on that holy grail quest for that one special instrument, not perfect mind you any rational student of optical theory knows, the shortcomings of beliving a 100% perfect errorless light gathering device exists...! . Perhaps as James mentioned in a recent posting with a 6in f8 R30 and a Raycorr, will be in my humblest hopeful opinion will be that one special instrument for many of us we can call perfection. Best Regards, Lance
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Post by jamesling1000 on Mar 22, 2013 5:00:24 GMT -5
Hi Lance....
Thanks for your comment.....
And I do hope other members also start to keep this forum active.....
Is not easy, as most members thought that this forum is strictly for commenting and discussion on Istar scopes...... But by now, and as the weather starts to warm up, I think should be able to see more Istar scopes in action.....
And I also want to bring back my Istar into action again, later part of this year, at my local side walk.....activities....., although now I have left it at my friend's place....
Regards
James Ling
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