View Single Post
  #13  
Old 19-03-2015, 06:23 PM
ausastronomer (John Bambury)
Registered User

ausastronomer is offline
 
Join Date: Mar 2005
Location: Shoalhaven Heads, NSW
Posts: 2,618
Quote:
Originally Posted by ralph1 View Post
What specific model is the kit? I also have a Celestron eyepiece kit, the 6mm is a plossl and difficult to look through. The 15mm while 'only' a kellner has quite a wide field of view, maybe 65 degrees but the field stop is quite blurry and there is astigmatism at the edge at F/5. Even with those flaws, it stacks up well against the 30mm bintel superview though.
Hi Ralph,

You can't compare a 15mm eyepiece to a 30mm eyepiece at all. Twice the TFOV assuming the same AFOV; and twice the coma in a Newtonian. Because of the larger field stop diameter most aberrations will be significantly increased in a 30mm eyepiece as compared to a 15mm eyepiece.

All of those eyepiece kits are a rip off, Meade & Celestron. You can buy better eyepieces for less money and most of the other accessories in those kits will most likely become case ornaments.

Cheers,
John B
Reply With Quote