DeltaOptical Plossl 40mm 45° 1.25″ eyepiece
If you are looking for a versatile eyepiece capable of panoramic low-magnification observations while delivering a sharp and high-contrast image, the DeltaOptical Plossl 40mm is exactly what you need. With a standard 1.25″ (31.75 mm) barrel diameter, it fits the vast majority of telescopes on the market - refractors, reflectors and catadioptric systems alike. Simply insert it into the focuser and you are ready to observe.
Classic Plossl optics with excellent aberration correction
The classic Plossl design consists of two achromatic doublets arranged to mutually correct optical aberrations. The result is an eyepiece with outstanding aberration correction - the image is sharp from the centre to the edge of the field of view, free from chromatic distortion and noticeable field curvature. All optical surfaces feature multi-layer anti-reflection coating (multicoating), which minimises unwanted reflections, maximises light transmission and delivers a vivid, bright image with high contrast. For astronomical observation this means fewer ghosts and flares even when aimed at bright objects such as the Moon or planets.
Wide field of view for low-magnification observations
The 40mm focal length makes this eyepiece ideal for low-magnification work and a wide true field of view. This is perfect for:
- locating objects in the sky
- sweeping star clusters, galaxies and nebulae
- enjoying a full-disc view of the Moon
The 45° apparent field of view contributes to comfortable viewing, especially during extended observing sessions.
Universal compatibility - fits most telescopes
The 1.25″ Plossl eyepiece for telescopes is designed with maximum versatility in mind. The standard 1.25″ barrel ensures compatibility with the majority of amateur and advanced telescopes without the need for any adapters. It is suitable both for beginners acquiring their first quality eyepiece and for experienced observers who need a reliable wide-field eyepiece with a long focal length.
Whether you own a compact refractor with a focal length of 600-900mm or a large Newtonian reflector at f/6 or above, the DeltaOptical Plossl 40mm is an essential part of your eyepiece set. The low magnification it provides is ideal for the start of an observing session - it makes it easier to point the telescope at your target and gives you a broad overview of the surrounding sky. The combination of anti-reflection multicoating and classic Plossl optics guarantees maximum light transmission and a contrasty image even under less favourable observing conditions.
About DeltaOptical
DeltaOptical is a Polish optics manufacturer with a long-standing tradition, focused on producing quality astronomical and observational instruments accessible to a wide range of customers. DeltaOptical Plossl eyepieces are manufactured with an emphasis on precise optical quality and durable mechanical construction. The brand is popular among amateur and professional astronomers alike thanks to its excellent price-to-performance ratio - you get optics with quality coatings and reliable build without overpaying. If you are looking for eyepieces that can handle regular use in the field as well as at a stationary telescope, DeltaOptical is a brand you can trust.
Key specifications
| Parameter |
Value |
| Focal length |
40mm |
| Barrel diameter |
1.25″ (31.75mm) |
| Apparent field of view |
45° |
| Optical design |
Plossl (4 elements in 2 groups) |
| Coatings |
Fully multi-coated (multicoating) |
| Compatible telescopes |
Refractors, reflectors, catadioptric systems |
