Askar 111F Flat-Field Refractor APO

Askar 111F Flat-Field Refractor APO

Description

The Askar 111F is a versatile Flat-Field astrograph developed for users seeking a high-performance and user-friendly solution for astrophotography and astronomical observation. Featuring a 111 mm aperture, a 766 mm focal length and a native focal ratio of f/6.9, it is suitable for deep-sky imaging as well as selected daily photography applications.

The optical system uses an air-spaced quadruplet APO design composed of three front lens elements and one rear element. The inclusion of one ED glass element effectively reduces chromatic aberration and provides high-contrast images with sharp and consistent stars across the entire field.

The optical tube incorporates an internal baffle designed to suppress stray light and further improve image quality. Compatible with full-frame sensors, the Askar 111F delivers excellent optical correction over the entire imaging surface.

Thanks to its integrated Flat-Field optical design, no additional field flattener is required. Users can directly connect imaging accessories, achieve focus and begin imaging without complex backfocus calculations, significantly simplifying setup procedures.

The Askar 111F is supplied with a photographic extension tube featuring a 2-inch filter thread together with M48×0.75 and M54×0.75 adapters for broad compatibility with DSLR cameras and dedicated astronomy cameras.

The mechanical design places strong emphasis on ergonomics and manufacturing quality. The retractable dew shield improves compactness and portability. The optical tube benefits from precision CNC machining and a refined finish continuing the characteristic blue-and-white visual identity of the F series.

The top handle integrates a finder base while both sides of the focuser also include finder mounting positions, allowing installation of finder scopes or additional accessories without disassembly.

The 3-inch rack-and-pinion focuser features a dual-speed mechanism with 1:10 fine reduction for precise focusing. The fine adjustment knob includes a protective cap designed to reduce the risk of damage. At the rear, a 360-degree graduated rotator allows precise camera orientation adjustments.

The 300 mm Vixen-style dovetail plate includes integrated 1/4-inch and 3/8-inch threaded holes for direct mounting onto compatible photographic tripods.

The Askar 111F represents a complete and versatile Flat-Field astrograph solution for users seeking a high-performance full-frame compatible imaging instrument.

Technical Specifications

• Aperture : 111 mm
• Focal Length : 766 mm
• Focal Ratio : f/6.9
• Objective Lens : Air-spaced quadruplet APO (including one ED glass element)
• Image Circle : 44 mm

Maximum Accessory Connection

(with the focuser fully retracted)

Imaging Mode

• 73 mm from the base of the M48×0.75 male thread
• 91 mm from the base of the M54×0.75 male thread

Observing Mode

• 132 mm from the end of the 1.25" eyepiece holder
• 142 mm from the end of the 2" eyepiece holder

Minimum Accessory Connection

(with the focuser fully extended)

Imaging Mode

• 43 mm from the base of the M48×0.75 male thread
• 61 mm from the base of the M54×0.75 male thread

Observing Mode

• 102 mm from the end of the 1.25" eyepiece holder
• 112 mm from the end of the 2" eyepiece holder

Total Length

• 664 mm including 1.25" adapter with dew shield retracted
• 751 mm including 1.25" adapter with dew shield fully extended
• 728 mm including photographic adapter with dew shield retracted
• 815 mm including photographic adapter with dew shield fully extended

Focuser

• Focuser Travel Length : 30 mm

Weight

• Net Weight : 5.74 kg
• Gross Weight (including tube rings and dovetail plate) : 6.76 kg

Rear-end Thread Type

• M78×1 to M54×0.75
• M54×0.75 to M54×0.75
• M54×0.75 to M48×0.75 (with M48×0.75 filter thread)

Standard Package Items

• 111F OTA
• Pair of tube rings
• Handle
• 300 mm Vixen dovetail plate
• Set of photographic adapters

Product introduction

The Askar 111F has 111mm aperture, 766mm focal length, and a native focal ratio of 6.9, suitable for various uses including astrophotography and daily photography.

The Askar 111F adopts a quadruplet lens design (three elements in the front, one in the rear), which includes an ED glass to effectively reduce chromatic aberration. 

The main tube features a built-in baffle that further blocks stray light and enhances image quality. The Askar 111F supports full-frame imaging, delivering delicate and sharp stars across the frame.

Featuring a self-flattened design, users can shoot directly after connecting imaging accessories and achieving focus. This eliminates the need for purchasing additional flatteners or calculating back focus, offering simple operation and a smooth experience.

The Askar 111F comes standard with a photographic extension tube, which is designed with a 2-inch filter thread. It includes adapters with M48*0.75 and M54*0.75 specifications, ensuring compatibility with DSLR cameras or astronomy cameras to meet diverse needs.

 

Adhering to Askar's consistent design philosophy, the Askar 111F emphasizes detail and user experience, striving to reduce the cost of use. The lens hood is retractable, further shortening the overall length and enhancing portability. The lens tube utilizes high-quality CNC machining and painting processes. Its appearance continues the F-series' classic blue and white color scheme, presenting a simple and elegant aesthetic.

 

The handle of the Askar 111F is equipped with a finder base slot. Additionally, both sides of the focuser feature finder bases. This not only allows for changing the finder scope position without disassembly but also provides more locations for installing other astronomical accessories.

The Askar 111F is equipped with a 3-inch rack-and-pinion dual-speed focuser supporting 1:10 fine adjustment. The fine adjustment knob includes a protective cap to prevent damage. The rear of the focuser connects to a 360° graduated rotator, allowing for precise angle adjustments.

The dovetail plate is a 300mm long Vixen-style plate, equipped with 1/4-inch and 3/8-inch screw holes, enabling direct connection to a tripod.

 

The Askar 111F, a multi-purpose self-flattened astrograph, starts your versatile deep-sky exploration journey with exceptional cost-effectiveness.

Product Size Diagram

Connection Diagram

Optical Path Diagram

Spot Diagram