DeltaOptical 2.5x Barlow lens 1.25″
Looking for a way to significantly expand the capabilities of your telescope without buying a whole new set of eyepieces? The DeltaOptical 2.5x Barlow lens is an elegant, optically precise solution that will be appreciated by beginners and experienced planetary and lunar observers alike. By multiplying the focal length by 2.5x, every eyepiece you own instantly gains several new effective magnification levels - and with an exceptionally clean, crisp image.
Apochromatic triplet optics - the key to outstanding image quality
The secret behind the exceptional optical quality of this Barlow is its apochromatic triplet construction - a three-element optical system designed to minimise chromatic aberration across three wavelengths of light. In practice, this means no distracting colour fringing around planetary edges and consistently high contrast even at maximum magnification. Compared to standard achromats or single-element lenses, this represents a significant qualitative leap that you will notice immediately when observing Jupiter, Saturn or the Moon.
Practical applications
Planetary astrophotography
A Barlow lens is one of the most popular accessories for planetary photography. When imaging planets with a webcam or dedicated planetary camera, you need a sufficiently large projected disc diameter on the sensor - and this is exactly where the 2.5x focal length multiplication makes a real difference.
Expanding your eyepiece collection
The lens is also an excellent complement to a basic eyepiece set. For example, if you own eyepieces with focal lengths of 10 mm and 25 mm, inserting the Barlow gives you effective values of approximately 4 mm and 10 mm - effectively doubling the number of available magnifications without any additional investment.
Universal 1.25″ barrel - fits most telescopes
The 1.25″ barrel diameter is the most widespread standard in amateur astronomy, so the lens fits the vast majority of telescopes and focusers on the market. Installation is instant - simply slide the Barlow into the focuser, then insert your chosen eyepiece or camera into the Barlow.
About DeltaOptical
DeltaOptical is an established manufacturer of astronomical optics, with a strong emphasis on precision craftsmanship and accessible pricing. Their products have earned a loyal following among astronomers across Europe, thanks to reliable quality that stands up well against more expensive competitors. The DeltaOptical Barlow lens is not a compromise - it is a well-thought-out optical accessory for those who refuse to sacrifice detail, even at the edge of the field of view.
Technical specifications
| Parameter |
Value |
| Magnification factor |
2.5x |
| Barrel diameter |
1.25″ |
| Optical design |
Apochromatic triplet |
| Chromatic aberration correction |
Three wavelengths (apochromatic) |
| Compatibility |
Suitable for visual observation and planetary imaging |
