Excellent, four-element Explore Scientific Focal Extener 2x Barl lens in 2 "frame, unparalleled quality of optics, highly recommended for astrophotography of the Moon and planets, equipped with a brass ring for safety and axial attachment of the glasses and photographic deposit.
The unique feature of Focal Extenders is their independence of the number of positions from the optical axis. For example - for most Barlow lenses, the number of times depends on whether we attach it before or after the eyelet. Either before or after the filter wheel, flip mirror or other reduction. In the case of Explore Scientific Focal Extenders, the focal lenght is always as declared - in this case 2-fold. The basic benefit of using Barlow's lenses is that they allow you to limit the number of glasses while providing a large span of available magnifications. For example, having 2 glasses with 30 and 15 mm focal lengths, using the Barlowa 3x lens we get an additional two magnification corresponding to 10 and 5 mm focal length lenses. In addition, the Barlow lens does not change the eye- shadow offset of the eyepiece ( eye relief ), allow you to focus farther away from the tube (when you have a problem with sharpening the image) and allow you to lengthen the focal length when shooting the sky at the focus of the lens by multiples the equivalent of the Barlow lens (2x, 2.5x, 3x, 5x).
In addition, Barlow lenses, especially those with a large number of times (2.5 - 5x), are often used for photographing the planets - they allow to obtain very long focal lengths and angular dimensions of objects when taking pictures in the focus. | • Multiplicity: | 5x | | • Construction: | 4 - element | | • Diameter of binding: | 2 ", has a mounting ring for 1.25" glasses | | • Anti-reflective layers: | FMC | | • Total length: | 118 mm | | • Diameter: | 66 mm | | • Weight: | 752 g |
2 years
HOW TO FIX THE LIGHT TELESCOPIC LENS
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