Askar 120 APO 120mm f/7 Triplet Refractor Telescope

Using the Askar 120APO for Astrophotography

The Askar 120APO has two optional accessories: a 1x flattener, and a 0.8x reducer. Both of them have built-in filter threads which allow direct filter mounting. Also, they have M54/M48 adapters which are convenient for attaching accessories.

The 1x flattener does not change the telescope's focal ratio itself. After connecting to the Askar 120APO, 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 120APO'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.

In terms of visual observations, the Askar 120APO offers the observer sharp and contrasty views. It can easily achieve focus when connected to 1.25" or 2" diagonals or various eyepieces. Because of the segmented lens tube design, a binoviewer can be used for visual observations.

Askar 120APO Optical Design

The Askar 120APO has an aperture of 120mm giving it an inherent advantage in terms of light-gathering power, resolution, brightness, and contrast, allowing the photographer to gather more light and resolve more detail in the image. The aperture area of the Askar 120APO is 36% greater than compared to that of the 103APO.

The 120mm aperture has a limiting visual magnitude of 12.2.

The Askar 120APO adopts a triplet air-spaced APO lens design, including one piece of ED glass.

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 120APO is equipped with a unique serial number for identification.

Askar 120APO Features for Astrophotography

Along with its optical design, the mechanics of the Askar 120APO is highly regarded among astrophotographers.

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 Askar 120APO has two finder bases, one on each side. Many users have some concerns about the limited space for installing additional astronomical accessories. To address this, we have specially set finder bases on both sides of the focuser. This not only eliminates the need for disassembly when changing the position of the finder scope but also provides additional mounting positions for other astronomical accessories.

The top ring mounting bar is also a handle bar for the Askar 120APO. It has a special slot design enabling the user to mount another finderscope or guidescope accessory. The handle itself has been extended by 60mm, which makes the tube rings more robust while cradling the telescope tube.

The standard Vixen dovetail plate is compatible with most equatorial mounts and saddles on the market. We extended the length and added screw holes, making the plate 290mm in length.  This makes it easier to balance on most mounts. With the slot on the handle, the spacing between the tube rings can be adjusted as desired. Additionally, there is also a larger Losmandy dovetail plate available for purchase.  This will enable the telescope to be mounted on a wider range of mounts.

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

The entire Askar 120APO 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 120APO 3.3-inch Focuser

The Askar 120APO is equipped with a large rigid 3.3" 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.

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 120APO Size & Weight

Askar 120APO is light and compact with a total weight of 14.3 lbs or 6.5kg (including the tube rings), making it ideal for both portable setups and observatory installations. The total weight of the two tube rings is 1.72lbs or 780g. The thumb screws enable easy opening and locking of the tube rings. Meanwhile, the base of the tube rings is heightened, providing more space between the tube and mount.

Askar 120APO Specifications

• Aperture size: 120mm
• Focal Length: 840mm (reducable down to 672mm with additional accessory)
• Focal Ratio: f/7 (reducable down to f/5.6 with additional accessory)
• Optical design: Triplet air-spaced APO (including one ED glass)
• Total tube length:
  • 722mm（when dew shield is contracted）
  • 804mm（when dew shield is extended）
• OTA weight: 12.6 lbs (5.7 kg)
• Dew shield OD: 139mm / 5.47"
• Gross weight (including tube ring and dovetail plate): 14.3 lbs (6.5 kg)
• Rear-end thread type: 2"/1.25" visual adapters included (imaging threads only possible with additional accessories)
• Mount attachment: 290mm Vixen-style dovetail included (Losmandy-style sold separately)