New Takahashi Products: TPL series eyepieces

Until recently Takahashi has been offering eyepieces with an apparent field of view of approximately 50°, including the Abbe series with 4 elements and the LE series with 5 elements.

Takahashi discontinued both series eyepieces and worked on designing a new type of eyepiece to replace these models. While designing these Takahashi repeatedly verified afocal calculations with various types of eyepieces and finally completed Takahashi's own original Plossl type eyepiece which is the best in its class!

There are many Plossl type eyepieces on the market, but they are a mixed bag, so unless you actually look through them, you can't really judge by the name Plossl.

The newly released Takahashi TPL series uses high-refractive, low-dispersion glass to correct central chromatic aberration as much as possible. The design  reduces chromatic aberration to about half that of the Abbe series and about 2/3 that of the LE series, so the image quality of the objective lens is delivered directly to the eye.

In addition, the entire surface of the lens is coated with a multilayer film that transmits more than 99% of visible light, and the metal construction is coated with a high-quality matte coating that prevents stray light from entering, making this eyepiece an eyepiece that allows you to enjoy stargazing with a field of view with good contrast.

This type of eyepiece, which does not include a Smythe lens, cannot reduce the Petzval sum correction to zero, so the star image up to the field ring cannot be made into a complete point image. Even so, the design has been optimized to balance astigmatism and field curvature so that the stars visible in the periphery are round with minimal deformation. The star image is extremely sharp from the center to half of the field of view and expands toward the periphery, but in the case of visual observation, the object is introduced at the center of the field of view, so you will be able to capture a high-quality star image.

The star image at the periphery is designed to bulge out in a natural shape, making it compatible with a high-quality Barlow lens, creating an almost flat field to every corner of the field of view.

The TPL-12.5mm, TPL-18mm, and TPL-25mm to be released this time also inherit the style of the Takahashi 31.75mm eyepiece, so they have the same focus as previous eyepieces and also feature a rubber eyepiece that can be folded back when using glasses.

The Takahashi TPL series is a high-performance eyepiece made in Japan that brings out the performance of a high-performance objective lens even though it is a PLossl type. This is a great product that TOA and Mewlon-CRS users should definitely try.

Main specifications

TPL-6

• Focal length: 6mm
• Eye relief: 4.5mm
• Apparent field of view: 48°
• Lens construction: 4 elements in 2 groups
• Size: φ39 x 39mm
• Weight: 55g

TPL-9

• Focal length: 9mm
• Eye relief: 6.5mm
• Apparent field of view: 48°
• Lens construction: 4 elements in 2 groups
• Size: φ39 x 45mm
• Weight: 70g

TPL-12.5

• Focal length: 12.5mm
• Eye relief: 9mm
• Apparent field of view: 48°
• Lens construction: 4 elements in 2 groups
• Size: φ39 x 51mm
• Weight: 90g

TPL-18

• Focal length: 18mm
• Eye relief: 13mm
• Apparent field of view: 48°
• Lens construction: 4 elements in 2 groups
• Size: φ39×60mm
• Weight: 110g

TPL-25

• Focal length: 25mm
• Eye relief: 18mm
• Apparent field of view; 48°
• Lens construction: 4 elements in 2 groups
• Size: φ39×71mm
• Mass: 140g