TS Optics Super 25mm 52° 1.25″ Reversed Kellner Eyepiece
The TS Optics Super 25mm eyepiece is a reliable choice for visual observation. With a 25mm focal length and a 52° apparent field of view, it gives you a wide, comfortable view of the night sky. The 1.25″ barrel includes a filter thread, so you can attach a planetary or Moon filter directly - no adapters needed. The 20mm eye relief keeps your eye relaxed, which is especially welcome during longer observing sessions.
Reversed Kellner design
This eyepiece uses a three-element Reversed Kellner optical design - one single element and one cemented doublet. The layout delivers good correction of aberrations at an accessible price, while keeping the eyepiece compact. Every glass-to-air surface carries an MgF2 anti-reflection coating, which reduces light loss and internal reflections. The result is a sharp, high-contrast image even on bright objects such as the Moon or the planets.
Wide-field overview eyepiece
A 25mm eyepiece is most commonly used as an overview eyepiece. At lower magnification, your telescope shows a wider area of sky, making it much easier to locate nebulae, star clusters, and larger double stars. The 52° field of view is wide enough to give a pleasant, natural impression - without the restrictive feeling of looking through a keyhole.
Key specifications
| Parameter |
Value |
| Focal length |
25mm |
| Apparent field of view |
52° |
| Barrel diameter |
1.25″ |
| Eye relief |
20mm |
| Optical design |
Reversed Kellner (3 elements) |
| Coating |
MgF2 anti-reflection coating on all air-to-glass surfaces |
| Filter thread |
Yes - standard 1.25″ |
Who is this eyepiece for?
Beginners
This is an excellent first eyepiece. The wide field of view and generous eye relief make it easy to find objects and comfortable to observe.
Experienced observers
The 25mm focal length fills a key role in any eyepiece collection - it provides the low-magnification, wide-field starting point that most observing sessions begin with.
Visual observers on a budget
The Reversed Kellner design delivers genuine optical quality without the cost of more complex designs. The MgF2 coatings keep contrast high across a range of objects.
