Baader Planetarium AstroSolar Safety Film Visual, 19.7" x 39.4" (50x100cm) 1 Sheet AstroSolar Safety Film 19.7" x 39.4" AstroSolar Safety Film 5.0 for solar observation and photography at high magnification, telescope quality, Optical Density (OD) = 5.0 Safe for visual solar observation (with additional optics) and imaging This highest precision film consistently produces strehl ratios of 94 to 96 percent at interferometric tests thus it performs optically like a Fluorite Triplet Lens by Carl Zeiss or Astro Physics