Nikon NAV-5SW 5mm Eyepiece

This wide-angle 5mm Nikon eyepiece combines a flat, wide field of view with a high eyepoint for easy viewing. The rubber eyecup and light-blocking hood make it easy to look through and block out ambient light, allowing you to enjoy astronomical observation in comfort.

Main Features

• With an apparent field of view of 72°, you can enjoy a wider actual field of view at the same magnification, allowing you to enjoy the impressiveness of outer space.
• Rather than focusing on numerical values, the eye relief is designed with performance as the priority, and the lens barrel is designed with ease of use in mind, ensuring a nearly constant distance from the end of the eyepiece to the eyepoint. Furthermore , exit pupil aberrations are effectively eliminated, minimizing blackout and coloration when the eye moves away from the eyepoint, improving usability.
• This advanced optical design combines a wide field of view with a flat image. It is compatible with the brightest F-numbers of the astronomical telescope objective optical system it is paired with. The NAV-5SW in particular is compatible with optical systems up to f/4. It improves the peripheral image without compromising the central image, minimizing field curvature and astigmatism.
• To eliminate stray light that is harmful to observation, light-shielding diaphragms, light-shielding wires, and black paint are used in appropriate locations, and the lens surfaces are multi-coated to reduce harmful reflections and improve transmittance, among other measures.
• The mounting diameter is 31.7mm or 1.25", the standard "American size." It can be used with various telescopes. It also features a parfocal design, with the flange at the focal point. *Please make sure the eyepiece insertion diameter of your telescope is 31.7mm.
• The eyecup rubber that comes into direct contact with the skin is made of skin-friendly silicone rubber, and features an easy-to-grip knurled design reminiscent of Nikkor lenses.
• A silicone rubber light-shielding hood is used to prevent external light disturbances when observing at high magnifications where close contact is not possible, or in places such as parking lots. Unlike the usual "horn-shaped" hood, it has a unique shape that can be used by people who wear glasses, and is flexible enough to reduce the transmission of vibrations. It is detachable and can be removed when not needed. 
• Drip-proof construction with rubber sealing to prevent night dew from seeping in.
• The optional TSA-1 telescope attachment allows for digiscoping. The FSB series compact digital camera bracket allows for collimated photography. It can also be used for lunar and planetary photography, expanding the scope of your photography.
• The innovative eyepiece converter "EiC-16" (sold separately) enhances the performance of NAV-SW eyepieces. The "EiC-16" converts the magnification to 1.6x. Unlike conventional Barlow lenses, the optical design optimized for the NAV-SW series increases magnification without sacrificing sharpness in the centre, further improving image flatness.
• The mounting system is a 31.7mm/1.25" chuck with minimal decentering error.

Specifications