Unlike many white-light solar filters that produce views of the sun with a red-orange, bluish, or yellow tint, the Alpine Astronomical 70mm Baader AstroSolar White-Light Solar Filter reveals the sun in its natural white color to show more surface details with greater clarity. The filter is mounted onto a clear-white IR-rejecting plastic ring, which acts as a stabilizing element for the filter cell, and the ring is in turn mounted onto the aluminum front frame. The thermal expansion coefficient of the plastic and the film are similar to minimize thermal stress on the film for increased resistance to developing pinholes or tears.
With the ability to be installed on the outside or inside of a binocular optical tube or camera lens, this filter provides a safe way to view the sun or to capture images with a camera. To fit most binocular configurations, one side of the filter housing is cut off and should be installed on the inside of the optical tube to prevent the housings from interfering with each other when the bridge is nearly closed. Recommended for objectives from 60-80mm, the filter is engineered with three centering bolts that can fit housings and lenses with an outside diameter of 101-116mm or an inside diameter of 75-90mm (if inside mounting is possible). Installation and removal are quick and easy with no tools or permanent modification to the optic or lens required. This is a single solar filter; for proper use on binoculars, two filters must be ordered.
- For the correct fit, measure the outside or inside diameter of the binocular optical tube or lens housing—including hardware like retaining rings and screw heads—and choose the size that matches the measurement with some extra room
- Recommended for 60-80mm objective lens diameters
- 75-90mm inside diameters
- 101-116mm outside diameter