Agema Optics Super Doublet Apochromatic Refractors

SD180

Agema Optics offers a Super Doublet Apochromatic Refractors that provide an optical design calculated to provide spectacularly high-contrast star and planet viewing and great color correction. They deliver true diffraction-limited images for the visual spectrum, and allows both visual observation and digital imaging.

Agema controls every step in its manufacturing process to guarantee the best quality final product; every mechanical and optical component is made in its machine shop. The company’s principals have enjoyed many years of professional experience in the field of precision optical devices.

Agema’s Super Doublet apos are offered in apertures of 120 mm ($4300US), 130mm  ($5900US), 150 mm ($9200US) and 180 mm ($16,500) with objectives of fluorite-doublets featuring a glass-in-front arrangement. Putting the glass in front protects the fluorite from any external influences.

Agema uses the highest quality optical materials for lens production, including glass that never undergoes secondary molding or annealing, and fluorite with optimal crystal orientation and uniform internal structure. Its complex lens cell eliminates the risk of deforming the optical components and protects them during telescope transportation. The cell design allows for fine adjustment of the lenses without disassembly – an important advantage.

Agema uses fluorite with unique dispersion properties, resulting in an optical system with high correction of chromatic aberration. Agema reports an amplitude of residual deviation 2.5 to 3.0 times smaller than the Abbe criterion for apochromatic lenses. The system’s Polychromatic Strehl Ratio exceeds 90 percent for the entire 430- to 700-nm visual range. Strehl Ratio graphs are provided for each model.

By carefully selecting its glass and fluorite and using the refractive index data from the actual glass melt, Agema produces optics precisely fabricated to the calculated design. Its improved polishing process provides a high-quality surface, and in combination with the low light scattering of fluorite, it delivers excellent contrast images.

Each lens is individually controlled during manufacturing and again at final assembly. All optical elements have broadband anti-reflection coating.

A field flattener, which improves the image quality in a larger field of view (a 60-mm clear aperture ensures a non-vignetting field for a 24-mm x 36-mm area/42-mm diagonal) is also available. The field flattener is designed to guarantee diffraction quality over the entire field of view without disturbing color correction.

The aluminum tube of Agena’s Super Doublet apos have internal baffles with knife edges that suppress indirect stray light. The tubes are equipped with extendable dew caps that reduce the entry of stray light and the chance of dew on the front lens. The inner surface is matte black; the exteriors are powder coated for a durable finish.

All Agema telescopes are equipped with a robust 3.5-inch focuser (draw tube size). The focuser has a 2-inch adapter with a collet-lock mechanism for attaching eyepieces, diagonal mirrors, prisms and other equipment. The field flattener can be installed by attaching it to the mating draw tube and securing it with the coupling nut.

The focuser has 125 mm of travel and dual-speed operation with an approximate ratio of 1:10. The backlash-free motion mechanism accomplishes a reliably smooth operation you can count on. Fixing the movable tube in any position is achieved with the drum-type brake conveniently located directly on the pinion shaft. This prevents damage to the rack if accidentally forced without releasing the brake. The focuser has all the necessary adjustments, including friction control that provides the ability to support different equipment weights.

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