ED Apochromats

Our ED apochromats use a very high homogeneity ED glass as the center element, full multi-coatings on all required surfaces, a fully temperature compensated lens cell, and zonal correcting non-equal internal radii. Computer optimizing these elements allows our lenses to satisfy the most serious planetary and deep space observer, as well as the most critical CCD or photographic user. Please send us your specifications or drawings for the quotation as we can supply a wide selection of these lenses; including cemented ED doublets, air-spaced ED doublets, cemented ED triplets, and air-spaced ED triplets. Also offering custom design capabilities, our optical designers are always available to assist with your special needs. Meanwhile, our factory in China is ready to meet your quantity requirements. Specifications: 1) Diameter: up to Φ305mm 2) Material: ED glass, or as requested 3) Surface quality: up to 40-20 S&D, or as requested 4) Surface accuracy: up to λ/20, or as requested 5) Clear aperture: >90% 6) Diameter tolerance: +0/-(0.05-0.2)mm (depends on the dimension) 7) Focal length tolerance: ±2% 8) Center thickness tolerance: ±0.2 9) Edge thickness tolerance: as requested 10) Bevel: (0.1 - 2mm) x 45° (depends on the diameter) 11) Coating: as requested