I have a pair of the Nikon Action 10X50s and they supposedly have a aspherical field lenses in the 60* EP's to prevent pincushion distortion. This may flatten the "wide field" view but does not cure edge distortion so you will always see some edge stars as "sea gulls" in any pair of binos in this price range. If you want true edge-to-edge sharpness AND a wide FOV your probably talking about $200 to $300 minimum for better Nikons, Pentax, or Fujion class glasses or settle for a smaller FOV.
Tom Mengel
Moderator Equipment Talk
“Insanity: Trying the same thing over and over and expecting different results”.
Albert Einstein
