Visual Solar Filter (280mm aperture)Fits tube ODs 312mm to 322mm
To ensure proper fit of the solar filter you must measure the outside diameter of the front opening of the telescope, binoculars or lens. To convert inch measurements to metric, multiply your tube diameter measurement that is in inches by 25.4. This will give you the diameter in millimeters.
NOTE: These filters cannot accomodate dovetail bars, counterweight bars or other accessories or devices that extend to the front of the telescope. If your telescope has accessories that will interfer with the fit of this particular filter, you must purchase the 6***-SF version of our filters.
A COSMETIC NOTE ABOUT BAADER SOLAR FILM
Unlike glass filters, Baader film does not have a perfect cosmetic surface. Wrinkles, folds, kinks, pinholes and other imperfections in this film are normal and will be present on any Baader film solar filter purchased from us. These do not affect the image quality or safety of the filter. Pinholes, even at full solar intensity, work as a camera obscura. This means that each pinhole would project its own solar image, just like eyepiece projection.
Anyone expecting or requiring a perfect cosmetic filter surface should consider another manufacturer's filter.
Having said this, know that Baader film filters are famous for their exquisite sharpness and detail across the entire field of view in an eyepiece and have a very pleasing and comfortable image brightness.
Also, this film is incredibly tough and does not break or tear easily. To puncture it with a blunt object takes a lot of force, much more force that would be used in normal day to day useage. And if by unfortunate chance the filter does get damaged, the film in the filter can be replaced. We will be offering internal replacement filter rings very soon.