Konus Kellner Eyepiece 1.25″ 20 mm – 1278 Review

What I Found Using the Konus Kellner Eyepiece 1.25″ 20 mm – 1278

The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 from Konus is an entry-level eyepiece designed to offer a wider field of view for beginner astronomers or those looking for a budget-friendly upgrade to their telescope’s stock eyepiece. It boasts a standard 1.25″ barrel size, making it compatible with a wide variety of telescopes, and a 20mm focal length, which is suitable for general observing and lower magnification viewing. Its affordability and versatility make it an appealing option, but the optical performance needs to be carefully examined.

My journey towards the Konus Kellner Eyepiece 1.25″ 20 mm – 1278 started when I needed a wider field of view eyepiece for my starter telescope. The kit lens was just too narrow, making it difficult to locate objects, especially when showing others the night sky. I was on a tight budget, but I wanted something that would improve the viewing experience without breaking the bank.

Unboxing the eyepiece, I immediately noticed its lightweight construction and simple design. The materials felt like a mix of plastic and metal, leaning more towards the former, which was expected at this price point. It felt robust enough for careful handling, but I wouldn’t want to subject it to any rough treatment.

I considered a few other budget-friendly options, including some generic Plossl eyepieces and other Kellner designs from different brands. I chose the Konus due to its seemingly reputable brand name and the availability of information about its compatibility with a range of Konus telescopes. The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 appeared to be the best blend of cost and known compatibility.

My first impression was a mix of hope and slight reservation. I was excited to see if it would truly improve my observing, but the simple construction gave me pause. I hoped the optical quality would be good enough to justify the purchase.

Real-World Testing: Putting Konus Kellner Eyepiece 1.25″ 20 mm – 1278 to the Test

First Use Experience

I first tested the Konus Kellner Eyepiece 1.25″ 20 mm – 1278 in my backyard, under moderately light-polluted skies. I wanted to observe the moon and some brighter deep-sky objects like the Pleiades star cluster. Seeing conditions were average, with some atmospheric turbulence.

The eyepiece performed adequately. It offered a noticeably wider field of view compared to my telescope’s stock eyepiece, making it easier to locate objects. The image was reasonably sharp in the center of the field, but significant distortion and chromatic aberration became apparent towards the edges.

I didn’t need much time to get used to the eyepiece; it’s a straightforward design. The eye relief was acceptable, but not particularly generous, so I had to position my eye carefully to avoid blackouts. The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 immediately showed its limitations.

Extended Use & Reliability

After several weeks of using the Konus Kellner Eyepiece 1.25″ 20 mm – 1278, I found that it consistently delivered a decent, but not exceptional, performance. It remained a useful tool for quickly scanning the sky and finding targets, but its optical shortcomings became more apparent over time. The edge distortion was increasingly distracting, especially when observing extended objects like nebulae.

The eyepiece has held up reasonably well, showing no signs of physical degradation. I’ve kept it stored in its original box when not in use, and it has not suffered any damage. Cleaning the lens is simple enough, requiring just a microfiber cloth and lens cleaning solution.

Compared to my previous viewing experiences with the stock eyepiece, the Konus Kellner Eyepiece 1.25″ 20 mm – 1278 is an improvement in terms of field of view. However, the increased distortion and chromatic aberration are trade-offs that ultimately make the image less pleasing than a higher-quality eyepiece, even with a narrower field of view. It does not outperform better quality eyepieces in terms of image quality.

Breaking Down the Features of Konus Kellner Eyepiece 1.25″ 20 mm – 1278

Specifications

• Focal Length: 20mm – Provides a lower magnification view, suitable for locating objects and observing larger celestial bodies.
• Barrel Size: 1.25″ – Standard size that fits most modern telescopes.
• Eyepiece Type: Kellner – A relatively simple and inexpensive optical design consisting of three lens elements.
• Optical Coatings: Multi-Coated – Designed to reduce reflections and increase light transmission, but likely basic coatings at this price point.
• Apparent Field of View: (Likely around 40-50 degrees, but not explicitly specified by the manufacturer) – This influences how much of the sky you can see at once through the eyepiece. A wider field is generally more desirable.

These specifications suggest an entry-level eyepiece suitable for beginners. The 20mm focal length is versatile for a range of telescopes, while the 1.25″ barrel ensures broad compatibility. The Kellner design is cost-effective, but it usually comes with limitations in image sharpness and edge correction.

Performance & Functionality

The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 performs its primary function: magnifying the image projected by the telescope’s objective lens. It provides a wider field of view compared to many stock eyepieces, which makes finding objects easier. However, the image quality suffers from noticeable distortion and chromatic aberration, particularly at the edges of the field.

Its strengths are its affordability and compatibility. Its weaknesses are its limited optical performance, particularly the edge distortion and chromatic aberration. It more or less meets the low expectations that come with the low price point.

Design & Ergonomics

The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 has a simple, functional design. It feels relatively lightweight, owing to its mostly plastic construction. The eye relief is adequate for casual viewing, but it might be uncomfortable for those who wear glasses.

It is user-friendly with no significant learning curve. Simply insert it into the telescope’s focuser and secure it with the set screw. The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 requires no prior knowledge of astronomy or telescopes.

Durability & Maintenance

The eyepiece appears to be reasonably durable for its price. The materials are not premium, but they should withstand normal use and handling. The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 should last for several years with proper care and storage.

Cleaning the lens is straightforward. A microfiber cloth and lens cleaning solution are all that’s needed to remove dust and fingerprints. Periodic cleaning will help maintain optimal image quality for the Konus Kellner Eyepiece 1.25″ 20 mm – 1278.

Accessories and Customization Options

The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 does not come with any additional accessories. Being a standard 1.25″ eyepiece, it is compatible with a wide range of filters designed for astronomy. Threaded filters can be easily attached to the eyepiece to enhance the view of specific celestial objects.

The eyepiece itself does not offer any customization options beyond the addition of filters. There are no adjustable features or interchangeable components, and Konus does not offer upgrades for this model. However, the Konus Kellner Eyepiece 1.25″ 20 mm – 1278 works perfectly fine with common 1.25″ accessories, as long as they are compatible with the telescope.

Pros and Cons of Konus Kellner Eyepiece 1.25″ 20 mm – 1278

Who Should Buy Konus Kellner Eyepiece 1.25″ 20 mm – 1278?

• Perfect for: Beginner astronomers on a tight budget, those seeking a wider field of view for their starter telescope, or casual observers who don’t require high-end optics.
• Who should skip this product? Experienced astronomers who demand sharp, distortion-free images, or anyone looking for high magnification viewing.
• Must-have accessories or modifications? A basic set of colored filters can enhance the view of planets and other celestial objects.

Conclusion on Konus Kellner Eyepiece 1.25″ 20 mm – 1278

The Konus Kellner Eyepiece 1.25″ 20 mm – 1278 is a budget-friendly option that offers an improvement over basic stock eyepieces in terms of field of view. However, its optical limitations, particularly the edge distortion and chromatic aberration, are significant drawbacks. It is a good entry point, but serious observers will quickly outgrow it.

The price is justified for what it offers – a basic, functional eyepiece that expands the viewing experience without breaking the bank. Its value is in its affordability and compatibility, not its optical performance.

I would recommend it with reservations to beginners who are on a very tight budget and need a wider field of view eyepiece. However, I would strongly encourage saving up for a higher-quality eyepiece as soon as possible. Start with the Konus Kellner Eyepiece 1.25″ 20 mm – 1278 if you must, but plan to upgrade!