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Help w/ Eyepiece selection

Started by Nemo, 10/16/2004 06:14PM
Posted 10/16/2004 06:14PM Opening Post
Hello friends,
As some of you may know I am waiting for the delivery of one TMB 115 CNC.(F/7)Although I have an extensive collection of 1.25 eyepieces I have no 2 inch EP's. I just purchased a 2 inch Televue Everbright diagonal. I would now like to start a collection of 2 inch eyepieces for my scope. I am particularly interested in the Televue eyepieces however there is a large assortment of them and I really could use a bit of advice. I would like to start out with an eyepiece that will give me the best detailed views of DSO's and Messier objects. I am looking for a balance between edge of field clarity (as much as can be had with out FF.)and wide field. I guess what I am trying to say is there an eyepiece that has the sweet spot for looking at DSO's and Messier objects that balances power versus field of view for this scope. I would like this eyepiece to be my first purchase and then go from there. If anyone out there would like to share with me some kind of list starting with the above described EP qualities I would be most appreciative. Another way to look at this request would be if you could only have one eyepiece for viewing the objects I have expressed interest in what would it be.
Money is not a consideration here. I am not looking for the best buy just the best EP in the Televue line.
Thanks for taking the time to read this.
R/S,
Dan

Danny Halstead
Moderator APM Forum
Posted 10/16/2004 10:34PM #1
Hi Dan,

The only true 2" eyepiece I own is the 31NT5 (and you can pry it out of my cold dead fingers). Everything else I need to do I can do with 1-1/4" eps up to the 24Pan.

My TV101 f/5.4 has a flat field and my Newtonian a coma corrector so I have not yet had to face the field flatness issue. You might want to check with TMB and find out at what diameter the field will be acceptable visually and then choose your ep field stop accordingly. In my case, going from the 24Pan to the 31NT5 gives me a 56% increase in f.s. dia.

Like Nils, I also own a 12NT4 and it is my most used ep in the TV101 both with and without Barlow. I no longer think of it as a 2" ep because I use the 1-1/4" barrel to keep the focus close to parfocal with my other TV ep's. (I would be embarrassed to admit how long I used the 12NT4 in 2" mode and had to rack the focuser way out and back in...)

Were I doing it today, I would probably just go for an 11 or 13 Nagler type 6. They weren't even available when I ordered the 12NT4 five years ago.

Clear skies,
Milt