TV nagler 13mm unable to focus

Andrea · Joined: 31 Dec 2005 Posts: 9

OK, I probably shouldn't have, but I bought a used Televue Nagler 13mm and now I can't seem to get anything to focus. No moon, no Mars, no stars. While adjusting the focuser and things are getting ready to come into focus I hit the end and the focuser can go no more. I have a bushnell northstar 525x3. Could the eyepiece be faulty somehow, or is there some trick. I made sure everything was tightened. I'm so very bummed. I was sure it was going to be a great view, but alas, it was not to be so. When I look through my new Celestron Omni 12mm and my new Meade 26mm 5000 plossl the moon is a sharp as could be. That TeleVue Nagler is so heavy, too. Didn't really expect that. A bit hard on the telescope motor. Also, I think it might be a Type 1 eyepiece. It doesn't look like any of the pictures of the Type 6 I see listed. There's no rubber eyeguard, there's a 1.25" barrel with a 2" skirt, there's no type number listed on the side, and this sucker is very heavy.

Am I expecting too much with my scope? Even used it was not cheap!
Andrea

Guest · Posted: Mon Jan 09, 2006 12:00 pm Post subject:

Hi

Sorry you are having a problem.

No one ever accused a Nagler of being lightweight, especially the 2"/1.2.5" model. Not sure why it isn't focusing, but I suspect it is not slipping all the way down inside your focuser, probably because the focuser was never designed to accept an eyepiece like this. I'd recommend returning it if you can and replacing it with a current Nagler that is strictly 1.25" such as the 11mm, http://www.opticsplanet.net/televue-nagler-en-11-type-6-eyepieces.html

Andrea · Joined: 31 Dec 2005 Posts: 9

Thank you. That is what I suspected. I'd be willing to hold onto this eyepiece for when I upgrade to another scope, one that accepts 2". What do you think? Would you? It's supposed to be a fantastic eyepiece. I'd hate to let it go with the hopes of using it in the near future.

Your recommendations are always appreciated.
Andrea

AstroBoy · Guest

Assuming there isn't something wrong with the Nagler, it could very well be that the 1.25" section is not seating properly into the focuser.

If you're detemined to hang onto it, instead of it collecting dust until you get something it fits in, you may be able to get an adapter or perhaps a Barlow that the Nagler will seat properly in and which will then seat properly into the scope. That will make it an even heavier load, though.

How long is the 1.25" section of the barrel? The Nagler 2"/1.25" combo units I've seen have an adapter ring with a thumb screw allowing you to adjust the 1.25" section. If your eyepiece is supposed to have this ring and it's missing, that could be a problem.

AstroBoy · Guest

Sorry, my description is confusing. If the 2" adapter ring has the thumbscrew, loosen it to allow you adjust how far in the 1.25" section goes into the focuser. If you find a spot where it focuses, tighten the thumbscrew to hold the position.

You might also check with Televue:

http://www.televue.com/engine/page.asp?ID=2

Andrea · Joined: 31 Dec 2005 Posts: 9

Thank you. I'm asking the original owner if I recieved everything I need for this eyepiece. I tried using a 2x barlow but that only makes it worse. I'm also thinking about taking it to a nearby community college with an astronomy class to see if they can get the eypiece to focus. I'd like to rule out what I can.
Televue is closed for the day and I'm gone the rest of the week, but I'll try to contact them as soon as I can. Thanks for the recommendations.
Andrea

opticsplanet.com · Posted: Mon Jan 09, 2006 5:53 pm Post subject:

Hi Andrea

Yes, that's by far your best option. If it doesn't work in another scope, you probably have a bad eyepiece.
_________________
----------------------
Your personal optics expert
Joanie (Jne) K
http://www.OpticsPlanet.com
Phone: (888) 263-0356
Fax: (847) 574-6820

Andrea · Joined: 31 Dec 2005 Posts: 9

...that's what I get for trying to save a few bucks.... Rolling Eyes