The ASA AZ800 is an azimuth mounted 0.8 meter telescope with Nasymth focus.
Compact Size: The azimuth design allows a very compact telescope, fitting in smaller domes compared to an equatorial telescope.
User Friendly: The Nasmyth focal point can be switched between the left and the right focus side by a mouse click within a few seconds. A direct drive motor in combination with a 0.1 arc second encoder and reference switch is used to turn the tertiary mirror. You could use one focus for visual observations while leaving your CCD camera installed on the other side. If you want to take an image of that object, all it takes is a mouse click. Of course you could also use 2 different CCD cameras, one installed with a ASA reducer for wide field imaging, the other one with a barlow lens for planetary work. Since all accessories are mounted in the center of gravity, there is no change in telescope balance when something is mounted or removed on the Nasmyth-Focus. Since there is also no focuser directly at the focus (focusing for both foci is done with the secondary), the weight of the CCD or accessories can be very heavy. The comfort in visual observing is stunning compared to a classical Alt-Az or an equatorial telescope because with the Nasmyth design the focus position and thus the view point is always at the same height.
Precise: With the AZ800 we have reached a new dimension of pointing and tracking accuracy. This is done with the direct drive and an ultra high resolution encoder with a readout of better than 1/100 arc second directly on the telescope axis. Zero backlash, zero periodic error. ASA has sold more direct drive mounts than any other telescope manufacturer. The azimuth design is also supporting overall better accuracies compared the equatorial telescopes because hysteresis effects, caused by optic shifts can be avoided. The ASA derotator is correcting the field rotation that is existent in Alt-Az telescopes. Even with 8m focal length, seeing limited exposures without any autoguiding is five minutes or more.
Perfect Optics: When it comes to optics, ASA doesn’t compromise. The optics are Harmer Wynne or Ritchey-Chrétien with optional correctors.
Item Number: Cassegrain: AZ800CA-TR; Ritchey-Chrétien: AZ800RC-TR
Aperture: 800 mm (31.50 inch)
Focal Length: Cassegrain: 7200mm (283.46 inch); Ritchey-Chrétien: 6400mm (251.97 inch)
Focal ratio: Cassegrain: f9; Ritchey-Chrétien: f8
Back Focus: 250 mm (9.84 inch)
Field of View: Cassegrain: 38 arc mins; Ritchey-Chrétien: 43 arc mins
Image Quality: 1.8 micron RMS spots [25mm on-axis] (400 to 900nm) 4.4 micron RMS spots [21mm off-axis] (400 to 900nm) 6.8 micron RMS spots [35mm off-axis] (400 to 900nm) (Spot and Diffraction Diagrams)
Material: High-end Aluminum parts and carbon fiber
Workmanship: CNC Manufactured
Fork: U-shaped fork with high stiffness
Optical Diameter: 800 mm (31.50 inch)
Mirror Diameter: 815 mm (32.09 inch)
Coating: Al+SiO2 with 91% Reflectivity
Surface Quality: L/8 PtV Wavefront >95 strehl
Thickness: 90mm (3.54 inch)
Cell: 18 point floating
Optical Diameter: Cassegrain: 250mm (9.84 inch); Ritchey-Chrétien: 287mm (11.30 inch)
Mirror Diameter: Cassegrain: 256mm (10.08 inch); Ritchey-Chrétien: 293mm (11.54 inch)
Coating: Al+SiO2 with 91% Reflectivity
Thickness: 40 mm (1.57 inches)
Optical Diameter: 150 mm (5.91 inches) on the minor axis with 97% Reflectivity
Thickness: 21 mm
Azimuth Motor: ASA Direct Drive Motor
Altitude Motor: ASA Direct Drive Motor
Encoder: High resolution Renishaw encoder
Motor Torque: Ca. 120 Nm
Control Software: Autoslew — ASCOM compatible; Pointing model calculates all repetable faults; Extremly accurate tracking without external guiding; Very accurate Positioning; Automated motor tuning; Home position; 2 Park positions.
ASA Software: Sequence — MLPT for local pointing models; Auto created pointing models.
Voltage: 24 V
Tracking Power Consumption: 0.5 - 4 amps
Absolute Current Peak: 15 amps
Pointing: < 8" RMS with Pointing File
Tracking Accuracy: < 0.25" RMS in 5 minutes
Encoder Resolution: 0.007" on the Axis
Moving Speed: 13°/sec
Cooler: Computer controlled fans
Focuser: Computer controlled motorized secondary mirror focuser
Baffle: Main mirror baffle