The Takahashi TPL 25mm eyepiece provides a 48 degree apparent field of view and extremely sharp on-axis performance.
Takahashi's TPL series are the definitive standard eyepieces, made in Japan and designed for use with high performance telescope systems where optical clarity is paramount. Stars are very sharp up to half the field of view, gradually swelling to the edge of the field. When combined with a short Barlow, the field is flat to the edge. Chromatic aberration at the centre is half that of the previous Abbe eyepieces and two-thirds that of the LE eyepeices.
Eye relief is about 70% of the focal length of the eyepiece. All TPL eyepieces are parfocal with the previous Takahashi 1.25" eyepiece series. The rubber eyecaps can be folded back for glasses wearers.
Comparison between TPL, Abbe and LE series eyepieces. Note: this is a geometric spot diagram when attached to an aberration correction objective lens, so it differs from the actual image.
|Lens elements / groups
||4 / 2
|Apparent field of view||48°|
|Eye relief||18 mm|