what is a diagonal

[chunky]

alright people whats is this? does it flip the ep view to the right way in a reflector? and any links to a good one ? is this one?

First Light Optics - William Optics 1.25" Carbon Fibre Dielectric Diagonal

also what other benifits are there

[brantuk]

You don't need a diagonal with a 200P dob. Basically though it's just a mirror at a 45 deg angle (like the secondary on your dob) that directs the light 90 degrees out the end of the tube for a more comfortable viewing position. You see them on the back end of refractors and Maks/Sct's

[Chris H]

A diagonal is used on refractors, sct's or Mak telecopes not Dobsonians. They bend the light path 90 degrees so you can use the eye piece much more easily. Just look at a picture of almost any refractor scope, the ep is inserted into the diagonal.

[chunky]

niiice one sabes me wasting money

[johninderby]

if you want any more info on the subject look at this link.

http://en.wikipedia.org/wiki/Star_diagonal

John