Pentax eyepieces are suited for all possible observations terrestrial or astronomical.
Be it deep sky objects with excellent image sharpness provided over the entire field of view or planets where centre point sharpness is critical.
Pentax have engineered their eyepieces to the exacting standards originally required by the astronomy community, and are among the elite few who use rare materials such as Lanthanum glass to optimise light transmission for unsurpassed clarity and brightness.
Successfully too, it seems, since astronomers and ornithologists agrees that Pentax are among the best available world-wide!