Askar 140 APO 140mm f/7 Triplet Refractor Telescope

Product Details

Askar 140APO Overview

The Askar 140APO is an OTA with a 140mm aperture, 980mm focal length, and f/7 native focal ratio. The Askar 140APO can be used in three possible configurations:

• Imaging at 980mm (f/7) with the 1x full frame flattener (sold separately)
• Imaging at 784mm (f/5.6) with the 0.8x full frame reducer/flattener (sold separately)
• Visual at 980mm (f/7) with either 2" or 1.25" eyepieces or a binoviewer (sold separately)

Using the Askar 140APO for Astrophotography

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.

Askar 140APO Optical Design

The 140APO's aperture of 140mm provides a increase in light-gathering power, resolution, brightness, and contrast over smaller aperture instruments.  This allows the photographer to gather more light and present more details in the image. The limiting visual magnitude is 12.5.

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

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

A triplet lens design will reduce chromatic aberration and provide finer details and color rendition. 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 Askar 140APO is equipped with a unique serial number for identification.

Askar 140APO Features for Astrophotography

The retractable design of the dew shield, along with the enlarged locking screw, provide easy adjustments if needed. The dew shield serves the purpose of protecting the lens from the impact of external and internal light along with protecting the lens itself.

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

The dovetail mounting plate of the Askar 140APO is the standard Losmandy dovetail plate, which is compatible with most equatorial mounts and saddles on the market. We extended the length and added screw holes, making the length 300 mm. This added length makes it easier to balance. 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 strengthened the overall stability to ensure that the alignment of 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 captain's style wheel-type locking ring that makes it easy to loosen or tighten.

When the adjustable tube is shortened, the Askar 140APO can be used with a binoviewer for visual observation. When the tube is extended, the 140APO can be equipped with a specific reducer or flattener for imaging or a 1.25"/2" diagonal and eyepiece for observing.

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 painted surfaces. The orange accents on the ivory-white tube add a bright and eye-catching touch, presenting a stylish and elegant overall appearance.

Askar 140APO 3.5-inch Focuser

The Askar 140APO is equipped with a large rigid 3.5" dual-speed rack and pinion focuser which is compatible with most motorized focusers on the market. There is a high-precision scale on the focuser's 10cm of travel. The entire focuser barrel is CNC machined with a internal design that reduces reflections, glare and stray light. It is painted matte black.

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 rotator with precise scales for convenient adjustment and saving of the rotation angles. It is also equipped with an enlarged rotator locking screw that can be easily secured even under high loads.

Askar 140APO Size & Weight

As a large aperture, long focal ratio telescope, the Askar 140APO was designed with portability in mind. The shortest overall length is only 735mm, the net weight is 20.3lbs (9.2kg), and the gross weight is 24lbs (10.9kg) including the handle, tube ring, and dovetail plate.

The Askar 140APO has an overall lightweight tube ring design, with an overall weight of 3.7lbs (1.7 kg). The thumb screws enable easy opening and locking of the rings. Meanwhile, the base of the tube rings is heightened, providing more space between the tube and mount.

Askar 140APO Specifications

• Aperture size: 140mm
• Focal Length: 980mm (reduced down to 784mm with additional accessory)
• Focal Ratio: f/7 (reduced down to f/5.6 with additional accessory)
• Optical design: Triplet air-spaced APO (including one ED glass)
• Total tube length:735mm (when dew shield is contracted）870mm (when dew shield is extended）
• The length of the rear retractable lens tube: 125mm
• OTA weight: 20.3 lbs (9.2 kg)
• Gross weight (including tube ring and dovetail plate): 24 lbs (10.9 kg)
• Rear-end thread type: 2"/1.25" visual adapters

What's in the Box:

• 1x Askar 140APO OTA
• 1x Pair of tube rings
• 1x Handle
• 1x Askar 300mm Losmandy dovetail plate
• 1x Oxford cloth case
• 1x Manual