Askar 71F Quadruplet Flat-Field APO f/6.9

Built-in Flattener: A 44mm Full-Frame Corrected Image Circle

The core of the Askar 71F is its quadruplet air-spaced APO objective, which includes an ED glass element to suppress chromatic aberration. Unlike conventional doublets or triplets, this design incorporates the flattener directly into the optical path. This provides a flat, corrected 44mm image circle without requiring you to purchase or calculate spacing for a separate corrector, ensuring sharp stars across a full-frame sensor right out of the box.

Imaging-Ready Mechanics: 3.0kg Portability and a 360° Rotator

Engineered for field use, the Askar 71F weighs only 3.0kg fully equipped with its included rings and 230mm Vixen dovetail plate. The 2.4-inch dual-speed rack and pinion focuser provides 50mm of travel and is robust enough to handle modern cooled astronomy cameras without slipping. For precise composition, a 360° rotator is integrated at the rear, allowing you to frame your target perfectly without rotating your camera and cables.

• Retractable Dew Shield: Reduces the telescope's transport length to as little as 372.5mm for increased portability.
• Multiple Finder Mounts: A slot on the handle and two finder bases on the focuser provide flexible mounting options for guide scopes and other accessories.
• CNC Machined Tube: The entire optical tube is CNC machined for durability and features internal matting paint to eliminate stray light reflections.

Versatile Connectivity: M64, M54, and M48 Adapters Included

The Askar 71F ships with a complete set of photographic adapters to connect your imaging equipment. The rear of the focuser terminates in an M64x0.75 thread, and the included adapters provide M54x0.75 and M48x0.75 outputs. The M48 adapter also includes threads for standard 2-inch filters, allowing you to easily integrate light pollution or narrowband filters into your imaging train without a separate filter wheel.

Askar 71F vs. Traditional APOs: The Value of a Self-Flattened Design

While a standard doublet or triplet refractor may have a lower initial price, it requires a separate field flattener for astrophotography, which adds cost and complexity. The Askar 71F's integrated design offers a distinct advantage.

• No Back Focus Calculation: With a traditional flattener, you must achieve precise 55mm spacing, which can be complicated by filter wheels and off-axis guiders. The 71F is self-flattened; you simply bring the camera to focus.
• Cost Efficiency: The price of a high-quality, full-frame flattener can be substantial. The 71F includes this correction as part of its native optical design, providing better value and a guaranteed level of optical correction.
• Simplicity: By eliminating an extra component in the imaging train, the 71F reduces potential points of tilt, flexure, and connection error.