Askar SQA106 106mm f/4.8 Quintuplet APO

A 106mm f/4.8 Quintuplet APO with 2 SD Elements

The heart of the SQA106 is its advanced Quintuplet air-spaced Petzval optical system. The SQA106 has great star performance, with excellent full-field illumination and MTF data.

To achieve this, the design incorporates two pieces of SD (Super-low Dispersion) glass. This low-dispersion glass reduces the color halos that can appear around bright stars. At f/4.8 the same exposure takes about 64% of the time needed at f/6.

The 509mm Focal Length: Framing the Sky's Largest Objects

With a native focal length of 509mm, the Askar SQA106 gives about 4.0 x 2.7 degrees on a full-frame sensor and 2.6 x 1.8 degrees on APS-C.

• The Andromeda Galaxy (M31): Fits a full-frame field with room around it.
• The North America Nebula (NGC 7000): Fits a full-frame field, with the Pelican Nebula (IC 5070) close to the edge.
• The Rho Ophiuchi Cloud Complex: Larger than one frame at 509mm, so plan a mosaic.

A Corrected 55mm Image Circle for Medium Format Sensors

The Askar SQA106 supports a 55mm image circle: medium format (55mm), which covers full frame (44mm).

A full-frame sensor sits inside it with margin.

48mm-78mm Back Focus with M48, M54, and M68 Adapters

The SQA106 provides a flexible back focus range from 48mm to 78mm, with a recommended distance of 55mm for optimal performance. Within this range you shoot directly once the OTA is in focus, with no additional back focus calculation.

The telescope includes three toothed and ribbed adapters that are easy to screw on:

• M68 Adapter: The largest connection.
• M54 Adapter: The middle size.
• M48 Adapter: M48×0.75, fitted to the OTA as delivered.

2.8-inch Rack-and-Pinion Focuser with 30mm Travel and 360° Rotator

The Askar SQA106 has a dual-speed 2.8-inch rigid rack-and-pinion focuser that is compatible with most motorized focusers. It has 30mm of travel, and the focuser tube is engraved with high-precision scales. Two finder bases sit on both sides.

Integrated into the rear of the focuser is a 360° high-precision rotator. Its precision scale lets you adjust and save the angle, and an enlarged locking screw locks it easily even under high loads.

Building Your Imaging Train on the SQA106

The recommended distance is 55mm, and 48mm to 78mm is supported.

• DSLR/Mirrorless Cameras: A DSLR on an M48 T-ring is typically built to 55mm; mirrorless bodies usually need extra spacing.
• Dedicated Astronomy Cameras: Most dedicated cameras have a native back focus of 6.5mm to 17.5mm. You will use a combination of the included adapters and optional extension tubes to reach the 55mm target distance.
• Filter Wheels & Drawers: Plan their optical length within the 48mm to 78mm range.
• Off-Axis Guiders (OAG): Count the OAG's thickness within the same range.

Imaging-First Build: Dew Shield, Rings, and 300mm Dovetail

The retractable dew shield takes the length from 516mm (contracted) to 586mm (stretched). The tube ring is an integrated pair with a hollow middle to reduce weight, and its top has a multifunctional finder base slot. The SQA106 is fully CNC machined with a fine oxidized coating.

A standard Losmandy-style 300mm dovetail plate sits on the bottom of the ring, and 6 M4 and M6 threaded holes on both sides take bases, dovetail plates or accessories.

8.12kg Gross Weight and 516mm Retracted Length

The SQA106 strikes a balance between aperture and portability. The optical tube assembly alone weighs 5.82 kg. With the included tube rings and 300mm Losmandy-style dovetail plate, the gross weight comes to 8.12 kg.

It ships in an Oxford cloth case with holes cut for the parts and extra space reserved for an EAF.

Your First Night Out with the Askar SQA106

Thanks to its integrated design, setting up the SQA106 for imaging is a streamlined process. After mounting the telescope and achieving good polar alignment, follow these steps:

1. Attach Your Camera: Use the appropriate M48, M54, or M68 adapter and any necessary spacers to connect your camera, aiming for the recommended 55mm (48 to 78mm supported).
2. Balance the Telescope: With all your imaging gear attached (camera, guide scope, etc.), balance the telescope on both the Right Ascension and Declination axes of your mount.
3. Find Focus: Point the telescope at a bright star. Use a Bahtinov mask and your camera's live view to achieve critical focus with the dual-speed focuser. Lock the focuser once sharp focus is achieved.
4. Frame Your Target: Slew to your desired deep-sky object. Loosen the 360° rotator, set the camera angle, then re-tighten its locking screw.
5. Begin Imaging: Start your autoguiding and begin your sequence of light frames.