Askar 140APO F/7 apochromatic refractor

Askar 140APO F/7 apochromatic refractor

The Askar 140APO is an OTA with a 140mm aperture, 980mm focal length, and f/7 native focal ratio.

The aperture of 140mm gives it an inherent advantage in terms of light-gathering power, resolution, brightness, and contrast, allowing the photographer to gather more light and present more details and brighter objects in the image. Along with more light coming into the astrograph, the limiting magnitude can reach 12.5.

The Askar 140APO adopts a triplet air-spaced APO lens design, including one piece of ED glass.

The Askar APO series employs special optical designs and multiple lens elements to correct chromatic aberration, naturally providing higher-quality object details and color accuracy.

In the refractor's element structure, increasing the number of lens elements and designing lens combinations can effectively improve chromatic aberration correction. However, this also means increased production costs and design complexity.

ED glass, also known as low-dispersion glass, is a type of optical glass specifically designed to reduce chromatic aberration.

Each piece of Askar 140APO is equipped with a unique name ring for identification.

The retractable design of the dew shield, along with the enlarged locking screws, provides convenient usage. The dew shield serves the purpose of protecting the lens from the impact of external and internal light.

The Askar 140APO has an overall lightweight design for the tube ring, with an overall weight of 1.7 kg. The thumb screws enable easy opening and locking of the tube rings. Meanwhile, the base of the tube rings is heightened, providing more space.

The handle of the Askar 140APO has a special slot design, making it also a base for installing a finder scope. The handle itself is 220mm long.

The dovetail plate of the Askar 140APO is the standard Losmandy dovetail plate, which is compatible with most equatorial mounts and bases on the market. We extended the length and added screw holes, making the length 300 mm, which is easier to balance on the mounts. With the slotted handle, the spacing between the tube rings can be adjusted as desired.

It is worth mentioning that the rear lens tube of the Askar 140APO has an integrated retractable design. We strengthen the overall stability and ensure that the optical axis will not be affected when the lens tube is stretched, thus guaranteeing the quality of the image. The retractable part also features a rudder-type locking ring that makes it easy to loosen or tighten.

When the lens tube is contracted, the Askar 140APO can be used with a binoviewer for visual observation. When the lens tube is stretched, the 140APO can be equipped with a specific reducer or flattener for imaging or a diagonal and eyepiece for observing.

In terms of visual observation,it can easily achieve focus when connected to 1.25" or 2" diagonals or various eyepieces. Because of the retractable lens tube design, it can also be attached to a binoviewer for visual observation.

n terms of the focuser, the Askar 140APO is equipped with a dual-speed rack and pinion large 3.5-inch rigid focuser, which can be compatible with most motorized focusers on the market. There is a high-precision scale on the 10-cm focusing travel. The entire focuser barrel is CNC machined with an anti-reflective internal design and matting paint, providing extra measures to eliminate stray light.

There are two finder bases on both sides of the focuser, which not only eliminates the need for disassembling when changing the position of the finder scope but also provides additional mounting positions for other astronomical accessories.

The rear of the focuser features a 360° high-precision big rotator, along with precise scales for convenient adjustment and saving of rotation angles, enabling precise rotation. It is also equipped with an enlarged rotator locking screw that can be easily secured even under high loads.

The telescope interface at the rear comes with a 1.25"/2" adapter.

The entire Askar 140APO tube is crafted using high-quality CNC machining with anodized and surface spray paint treatments. The orange accents on the ivory-white tube add a bright and eye-catching touch, presenting a stylish and elegant overall appearance.

The Askar 140APO has two optional accessories: a 1x flattener and a 0.8x reducer. Both accessories come with a built-in 2" filter thread for direct filter mounting. The 0.8x reducer is equipped with M54/M48 adapters, and the 1x flattener is equipped with M68/M54/M48 adapters for easy connection.

The 1x flattener does not change the telescope's focal ratio itself. After connecting with the Askar 140APO, it still maintains a focal ratio of f/7. The flattener corrects field curvature and coma, resulting in flatter field edges and finer star points.

The 0.8x reducer can bring the Askar 140APO's focal ratio down to f/5.6. This is a standard reducer with field flattening capabilities as well. A shorter focal ratio allows the OTA to have a wider field of view and faster exposure times, making it suitable for capturing large areas of nebulae, star clusters, and faint, fast-moving celestial objects.

Whether you're an astronomy amateur, a professional astrophotographer, or just a regular person with a curiosity about the universe, the 140APO will fulfill your needs. No longer do you have to sacrifice quality to fit the budget; let's start your journey to the stars with the Askar 140APO!

Specifications

• Diameter: 140 mm.
• Focal length: 980 mm.
• Focal ratio: F/7.
• Optical design: air-spaced triplet apochromatic refractor with central ED lens.
• Total length: 735 mm with dew-shield fully racked in, 870 mm with dew-shield fully racked out. An integrated sliding extender allow the tube to be further lenghtened up to 125 mm.
• Weight: 9.2 Kg OTA only, 10,9 Kg with rings and dovetail.
• In the box: Askar 140APO refractor with rings, top handle, bottom type Losmandy-D dovetail plate 300 mm long, Oxford cloth case

Size

Optical design and performances