Celestron Ultima LX & Astro Tech AF, 13mm, anyone?
Posted 13 December 2012 - 07:55 PM
I'm looking for some feedback on the Celestron Ultima LX and the Astro Tech AF, in the 13mm length. I'm looking particularly for experiences with their use in fast Newtonians. f/4 & f/4.5 are my Newt's. These two EPs are the same beast.
The 13mm Hyperion is not in the game as they are not suited to my fast Newt's. The 13mm LVW and similar Delos are over my budget.
I have the 8mm LX, and it is a lovely EP in my scopes. Along with good reports on the 17mm LX, I'm exploring the candidacy of the 13mm LX. I'm not expecting LVW performance, just a resonable, respectable one.
I'm also limiting the AFOV to no more than 72*. Anything 80* and over isn't in the running either.
Thanks in advance,
Posted 14 December 2012 - 12:34 AM
As you already know, I did a review on the 17mm Celestron Ultima LX. At first I really liked the eyepiece. Then, over time, I began to see more and more field curvature. I think it was because I tested it in light polluted skies, and then went to a dark sky site, I am not positive.
Anyways, I never owned it very long because at first I didn't really notice the field curvature and after testing it again in darker skies, it seemed worse, so I sold it and bought two Vixen LVW's. Eye positioning and comfort was excellent on it, (The 17mm Ultima LX), and the FOV felt wider than the 70 degrees, but the field curvature in my fast scope just killed it for me with that EP.
I now own the 13mm and 22mm Vixen LVW's and I plan on getting the 17mm Vixen LVW and maybe even the 5mm LVW as well.
Only 65 degrees or just under that, but it is 65 degrees of pure sharpness almost right out to the field stop in my 10" reflector without a Paracorr. I can only see a tad of extremely MILD coma from the 22mm Vixen LVW, and I am talking about 90% outwards. The 22mm Vixen LVW is incredible in a fast scope.
I must have went through 5 or 6 eyepieces until I tried out the 22mm and 13mm Vixen LVW's and I am glad I found them! I would recommend that you save up and just WAIT until you find a Vixen LVW or two, (or three or more!), or you'll just end up going through the crud to get to the diamonds.
I just came back from a dark site I go to and I was using the 22mm and 13mm Vixen LVW's tonight and they are the most comfortable eyepieces I have ever looked through. I also had the chance to trade my 10mm Pentax XW for a 9mm ES 100 and turned the offer DOWN. I plan on getting the 17mm Vixen LVW down the road and maybe even the 5mm LVW too!
IMHO, the best way to view through the Vixen LVW's is to take the rubber eye cup right off. That way you get more of the immersive feeling like Uber Wides.
Another thing you may consider trying is the 30mm 1RPD with a 2x GSO ED barlow for the close equivalent to a 15mm / 80 degree eyepiece that may get corrected edge wise by the barlow lens! I don't know if the eyepiece will vigenette in the barlow though?.....That would be something to try out. I read that someone tried it and the results were good.
Posted 14 December 2012 - 07:37 PM
I borrowed a mate's 13mm & 8mm LVW's, and all I can say about them is OOOHHHH! Lovely!
The 8mm was easier on my eyes than the 13mm, which I mentioned to my friend. He's got the entire range of LVW's, and also says the 8mm is the easiest on the eye of all the LVW's - and none of them are poor for that matter.
I may well need to just wait & save, but I'm still on the look out for those sneaky little gems that are modestly priced (not that there's anything LITTLE about the LX's).
Posted 17 December 2012 - 05:19 PM
These seem to be just about unknown,
Not all stablemates are the same in any series. Wondering how these do.