Astrographe Telephoto ASKAR SQ555

Super Fine Star point 

Quintuplet air-speed lens design, including 1 piece od SD glass ans 1 piece of ED glass
The central star point has an RMS of less than 2.5um, and the star point at the corner is less than 4 um, showing a super fine star point

PETZVAL lens structur

Self-flattened design, no need to calculate specific backfocus between 50mm and 60mm connection distance, users can directly use it for shooting after OTA is focus

1. Filter Thread
   At the end ot the OTA, it is equipped with M48 adapter which has a built-in 2" filter thread for direct connection of 2" filters
   
   

2. Quick Release base position
   
   There are faur multi function quick release bases on the rear of the lens tube which can be used to connect various accessories for photography and astrophotography, and can be also be perfectly matched with the accessories of the SQA series

• Camera Quick release base

Camera Quick release knobs on the top handle and bottom bracket which can be use to convert the OTA to camera lens mode manually and quickly without additional tools

• Bracket

The Bottom bracket has a 1/4 and 3/8 screw holes for attaching tripod

• Dovetail plate

The dovetail plate is a standard VIXEN style 200mm dovetail plate. The bottom of the dovetail plate is design with hand screws and a quick release knob which bcan be disassembled and assembled without additional tools.

• Handle

The Handle has a finder base slot which can connect different astronomical accessories. Handle is a quick release design and can be removed without tools

Dual speed focuser Design

Fine adjustment and coarse adjustment can both be adjusted independently.
Fin adjustment designs a central indicator point, a focusing travel of +-1mm and a locking screw

The Coarse adjustment is engraved with a reference scale for focusing distance in both imperial and metric marking. In daily photography, focusing can be adjusted according to the focusing scale for reference. The croase adjustment handwheel is equipped with MXL-type timing teeth which can be used with a timing belt to mount a electronic focuser.

For astrophotography, The croase adjustment can be rotated to the infinity mark for focusing a,d there is still a certainamount of leeway after the infinity mark thanks to the self flattened design between 50mm and 60mm connection distance, users can directly use it for shooting after the OTA is focus which make it easy to connect the telescope with the necessary accessories.
Coarse adjustment is also designed with a locking screw for individual adjustment.

Features

• Aperture size: 55mm
• Focal length: 264mm
• Focal ratio: f/4.8
• Objective lens: Quintuplet petzval APO（One piece of SD glass, one piece of ED glass）
• Format specifications: 44mm
• Aperture blades: 14 pieces
• Graded Aperture: f/4.8-f/22
• Closest Focus Distance: 5m
• Focusing mode: Manual focus
• Front Filter Diameter: M67
• Total length: 316mm (inclulding dew shield); 244mm (without dew shield)
• OTA weight: 1.84kg
• Total weight (including handle & dovetail plate): 2.18kg
• Rear-end adapter: M48*0.75 (with M48×0.75 filter thread)
• Rear-end connection distance: Support 50-60mm range (Recommended connection length is 55mm)
• Standard package items: a SQA55 OTA, a military-grade waterproof hand-carrying case