Askar FRA is a series of telescopes designed for use in astrophotography, featuring the highest optical and mechanical quality, as well as a built-in field corrector.
The Askar FRA600 600 / 5.6 APO is a high-class astrograph that is a development of the FRA400 model, whose optical system consists of five lenses arranged in two groups. In order to eliminate the phenomenon of chromatic aberration, the manufacturer used in this instrument as many as two lenses made of glass with reduced dispersion, while obtaining high contrast is possible thanks to coating glass surfaces with multilayer anti-reflective coatings.
This device is characterized by a high light of f / 5.6, which can be further increased by using a separately available, dedicated focal length reducer. This design, both mechanically (a solid 4.2 "hood with a microfocuser) and optically (large diameter circle full illumination) has been optimized for cooperation with cameras and cameras equipped with into a full-frame matrix.
• apochromatic quintuplet with two elements made of ED glass and a built-in two-element equalizer
• cut out with a diameter of 4.2 "allowing to maintain the alignment even with a high load
• large diameter of the full illumination wheel, as much as 66 mm, guaranteeing the coverage of the full-frame matrix
• optical system: ED-APO apochromatic quintet with air gap
• number of ED glass elements: 2
• Objective diameter: 108 mm
• focal length of the lens: 600 mm
• maximum useful magnification: 324x
• lighted: f / 5.6
• anti-reflective coating: full multi-layer coating (FMC)
• circle diameter of full illumination: 66 mm
• built-in field equalizer: yes, two-element
• back focus: 160 mm from the M91 thread
• exhaust diameter: 4.2 ", reduction to 2" and 1.25 "
• type of eyepiece extractor: rack & pinion with 10: 1 microfocus and the possibility of rotation by 360 °
• adapter for connecting the camera or camera: M90x1 - M48x0.75 / M54x0.75 - M48x0.75
• mounting foot: Losmandy
• length: tubes: 493 mm
• tube diameter: 125 mm
• tube weight: 6.5 kg
• Askar FRA600 600 / 5.6 APO optical tube
• fastening rings
• carrying handle
• dovetail footer in the Losmandy standard
• M90 / 2 eyepiece adapter
• reduction 2 "/ 1.25"
• two-section M90 / M48 adapter
(Object: America Nebula / Pelican Nebula, (Cygnus);
click to enlarge in Astrobin [KLIKNIJ])
Setup: Askar 108 FRA600 dla potencjalnego klienta + ZWO 294 MM-P, ZWO HSO 1,25, Sky-Watcher EQ6-R