Description
The BRESSER 2x Barlow Lens is an optical accessory with a standard 1.25" (31.8 mm) mounting diameter that doubles the magnification of any eyepiece. It is installed between the telescope and the eyepiece and doubles the effective focal length of the telescope, effectively making each eyepiece twice as powerful. Thanks to this, one Barlow doubles the entire set of eyepieces, allowing you to obtain high magnifications while maintaining a convenient large eyepiece and comfortable pupil distance of the long-focus eyepiece. The two-lens design with multilayer illumination provides a high-quality image across the entire field and is suitable for both visual observations and photography. A feature of this model is a removable black optical block with a 1.25" filter thread, which can be screwed into the eyepiece, T-adapter or other accessory for flexible magnification change. When screwed into the nose of a standard T-adapter, it provides about 1.6x magnification on a SLR camera, helping Newtonians and solar telescopes with short working distances to focus for shooting. The aluminum body makes the accessory lightweight and durable. It's one of the cheapest ways to double the capabilities of your existing eyepiece set.
How it works (doubling effect on your glasses)
A 2x Barlow lens doubles the magnification of any eyepiece β or, what is the same, halves its effective focal length:
40 mm eyepiece β works like 20 mm
20 mm eyepiece β works like 10 mm
15 mm eyepiece β works as 7.5 mm
10 mm eyepiece β works like 5 mm
Total magnification = telescope focal length Γ· eyepiece effective focal length. It is important to keep the result within the useful magnification of the telescope (approximately twice the objective diameter in millimeters): for example, on a 70 mm telescope the ceiling is about 140x, on a 90 mm telescope it is about 180x, on an 8-inch (203 mm) telescope it is about 400x.
Design features:
- Doubling magnification (2x) β the lens exactly doubles the magnification of any eyepiece. This allows you to get two different magnifications from one eyepiece β without and with a Barlow. In effect, the set of eyepieces doubles in the number of available steps. The user gets more zoom options at minimal cost.
- Double-lens illuminated design β an optical scheme of two lenses with multilayer illumination of all surfaces. It provides a high-quality, contrast image across the entire field of view. Illumination reduces parasitic glare and light loss. The user does not lose image quality when adding a Barlow.
- Removable optical block with 1.25" filter thread - the black optical block can be unscrewed and has a standard 1.25" filter thread. This allows you to screw it directly into the eyepiece, T-adapter or other accessory and flexibly change the magnification. In different configurations, the effective magnification differs from the basic 2x. The user gets several application scenarios from one accessory.
- Dual purpose: visual and photo - Barlow is equally suitable for eye observations and astrophotography. In visual, it increases the magnification, in photo - the scale of the object on the matrix. Two-lens illuminated optics maintain quality in both modes. The user uses one accessory for both viewing and shooting.
- Focusing aid for astrophotography - the optical unit screwed into the nose of a standard T-adapter provides about 1.6x on a SLR camera. This adds a working distance and helps Newtonian and solar telescopes that lack focuser travel to reach the focus point for the camera. Without this, direct focus shooting on such telescopes is often impossible. The user gets a practical tool for their first astrophotography.
- Halving the effective focal length of the eyepiece - Barlow allows for high magnification...
