Which diagonal ?

[astropolak (Joe)]

Hi Everyone
Thank you for all the advice I received about eyepieces, I now have a superb Pentax XW 10mm ocular.
Only now I can actually test the rest of the optical path, got the collimation almost perfect and have concluded that my 2" Andrews diagonal produces larger star dot than the standard 1 1/4 prism diagonal (this is on my Meade LX90). I attribute this to poor quality mirror but welcome any other suggestions...
Looking for some concrete advice and opinions about 2" diagonals or diagonals in general. I am looking at William Optics 2" diagonals as a possible replacement.

Please post your thoughts on this matter

RGDS Joe

[gbeal]

Get the best you can find/afford.
Never sell it, and consider it an investment forever.
I have a Zeiss M44 prism, and it is awesome, but also have the 2" Baader/Zeiss prism. It is a monster, but it is the keeper.
The W/O (I think there are two sorts) are very highly regarded.

[Striker (Tony)]

I have 2 x WO 2" Dielectric diagonals...their fantastic.

[Robert_T]

I'd second Tony's support for the WO 2" diagonals - they'd have to be the best quality for $ available.


cheers,

[xstream (John)]

Joe,
You won't get the full benefit of a 2" diagonal on the LX90 because of the 1.3/4" opening on the back; But go the William Optics as it's a huge improvement on the 1.5" Diagonal

[ausastronomer (John Bambury)]

Hi Joe,

I am glad to hear you went with the 10mm Pentax XW. I was confident when recommending it that you would like it. It is one of the very best eyepieces money can buy.

I agree with the others in getting a good diagonal, the overall quality of the optical system is only as good as its weakest link, expensive eyepieces coupled with poor diagonals or barlows give poor quality views.

As has been mentioned, the WO dielectric diagonal is superb but expensive, the standard WO diagonal is very good and a bit cheaper. You can order these from:-

www.frontieroptics.com

Daniel Beringer runs Frontier Optics and is an excellent person to deal with. As in Ice in Space member he will do you a good deal.

CS-John B