Baader AstroSolar Telescope Filter 240mm - OD 5.0 - ASTF-240

Baader AstroSolar Telescope Filter 240mm - Tubes 260-300mm OD

• Safe for solar observation and photography with all high-end telescopes and extreme tele-lenses. Suitable for highest magnifications and detailed observation of individual sunspots
• AstroSolar Safety Film OD 5.0, mounted stress free in temperature compensated cell
• No astigmatism during winter observation or with temperature changes in summer
• Scope of supply: ASTF Filter with apertures from 80 to 180mm (200 – 280mm not yet available) come with two sets of centering bolts in 38mm length. 3 bolts with 10mm diameter and 3 bolts with 20mm diameter, adjustable to the tube diameter of your telescope or dew cap. In addition three safety straps with glue-pads and three rubber plugs to cover the holes that are not used, mounting instructions.

Baader Solar Filters provide a professional and secure solution to observe and image the Sun using AstroSolar® Safety Film Optical Density of 5.0. Many ready made filters do stretch the filter material like a drumhead in order to make it look like a piece of glass – this absolutely destroys the image quality, rendering the film useless for high magnification work. AstroSolar must be mounted entirely stress free in order to perform like a high precision flat window. It sounds like a contradiction with traditional perception of quality, but AstroSolar must show slight ripples! With this specially designed mounting, the Baader AstroSolar Telescope Filter with Optical Density of 5.0 provides exceptional optical imagery.  In fact, after 15 years of offering AstroSolar film sheets as a DIY-product, this system of Baader Solar Filters™ is designed to retain the true optical quality of the diffraction-limited AstroSolar Safety Film, even used at high magnifications.