New Askar products: triplet APO refractors

After a long preparation, Askar launches the new Askar APO series refractors, dedicated to enabling more amateurs to own a high-performance astrograph and explore the mysteries of the universe to their heart's content without worrying about the price.

The Askar APO telescopes have a triplet air-spaced APO lens design, including one piece of ED glass. Available in 103mm, 120mm, 140mm and 185mm aperture.

APO (Apochromatic) telescope is a type of telescope with the ability to correct chromatic aberration. Chromatic aberration is a common optical aberration that causes colored edges or blurring around the edges of objects in an image. Other telescopes have relatively simple optical designs and are prone to chromatic aberration, especially at high magnification or in observations where color accuracy is required. However, APO telescopes employ 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. Chromatic aberration occurs because light of different wavelengths refracts differently when passing through a lens, leading to color separation and a decrease in image quality. ED glass has special optical properties that help reduce stray light and effectively minimize chromatic aberration.

The Askar APO telescopes not only adopts a triplet lens design (while budget astrographs on the market typically use doublet), but it also has an ED glass to further enhance image quality.

In addition to the carefully designed lens itself, every aspect of the Askar APO is dedicated to providing a better astrophotography experience for users.

All the inner of the Askar APO's dew shield is covered with matting felt, while the inner walls of the main tube are coated with matting paint and equipped with the internal baffle. This effectively reduces light scattering and reflection inside the OTA, thus enhancing the brightness, contrast, and resolution of the observed targets.

Each piece of Askar APO is equipped with a unique name ring for identification, making each Askar APO telescope exclusive to its owner.

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 and protecting the lens itself.

On the Askar APO, there are a total of two finder bases. Each side of the focuser is equipped with a finder base. Many users have expressed concerns about the limited space for installing additional astronomical accessories along the use. 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 finderscope but also provides additional mounting positions for other astronomical accessories.

The handle of the Askar APO has a special slot design, making it also a base for installing a finder scope. The handle itself is sturdy and durable.

The overall design of the tube brings is lightweight. The thumb screw of the tube ring allows for easy opening and locking. At the same time, the raised base creates more space to accommodate astronomical accessories. In everyday use, the convenience of each step is taken into consideration.

The dovetail plate is the standard Vixen or Losmandy dovetail plate, compatible with most equatorial mounts and bases on the market. We have also made additional extensions and hole position designs, the length reaching up to 290mm, making it more convenient for balancing on the equatorial mount. With the slot on the handle, the spacing between the tube ring can be adjusted as desired. Additionally, there is also a Losmandy or Vixen dovetail plate available for purchase, to be used with different equatorial mounts.

The detachable main tube design makes it possible for an OTA to down the focal ratio of F4. It can also be used for observations with binoviewer!

Optical design

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

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. Askar APO series employs special optical designs and multiple lens elements to correct chromatic aberration, naturally providing higher-quality object details and color accuracy. ED glass, also known as low-dispersion glass, is a type of optical glass specifically designed to reduce chromatic aberration.

Mechanical design

As for the dedicated optical design, the Askar APO line of refractors are well-considered in the mechanical design too.

Light and compact

Askar APO was designed with portability in mind. Due to the retractable lens tube design, the overall length is relatively short and the net weight is kept low.

Askar APO is light and compact with a low weight (including the tube rings). So it is suitable for outdoor shooting.

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

Retractable dew shield

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 and protecting the lens itself.

Multiple finder bases

The Askar APO has two finder bases, one on each side. Many users have some concerns about the limited space for installing additional astronomical accessories along the use. 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.

Handle

The handle of the Askar APO has a special slot design, making it also a base for installing a finder scope. The handle itself has been extended, which makes the tube rings more convenient to fix the astrograph.

Weight

The tube ring is very light in weight. The thumb screws enable easy opening and locking of the tube rings. Meanwhile, the base of the tube rings is heightened, providing more space.

Losmandy/Vixen dovetail plate

The standard Losmandy or Vixen dovetail plate is compatible with most equatorial mounts and bases on the market. We extended the length and added screw holes, making the plate becoming 290mm which is more easy to balance on the mounts. With the slot on the handle, the spacing between the tube ring can be adjusted as desired. Additionally, there is also a Losmandy or Vixen dovetail plate available for purchase, to be used with different equatorial mounts.

Optional accessories

The Askar APO has two optional accessories (at time of release): 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.

Flattener

The 1x flattener does not change the telescope's focal ratio itself. After connecting with the Askar 103APO, 120APO, 140APO or 185APO it still maintains a focal ratio of F7. The flattener corrects field curvature and coma, resulting in flatter field edges and finer star points.

0.8x and 0.6x Reducer

The 0.8x reducer can bring the Askar103APO's focal ratio down to F5.4 and the Askar 120APO, 140APO and 185APO's focal ratio down to F5.6. 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. Askar103APO even has an 0.6x reducer bringing the focal ratio down to F4!

Segmented or retractable tube design

In terms of visual observations, the Askar APO pays great attention to observation quality. It can easily achieve focus when connected to 1.25" or 2" diagonals or various eyepieces. Because of the segmented or retractable (185APO) lens tube design, it can also be attached to binoviewer for visual observation without the needed use of a barlow!

3.3 inch dual speed focuser

In terms of the focuser, Askar PO is equipped with a dual-speed rack and pinion large 3.3-inch rigid focuser, which can be compatible with most motorized focusers on the market. There is a high-precision scale on the 10cm 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.

Rotator

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 easily secure even under high loads.

Adapter

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

Materials and esthetics

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

Askar APO

Let the Askar APO accompany you in exploring the magnificent landscapes of the universe and create unforgettable memories. Take action now and embark on your astronomical adventure with the Askar APO!

Askar 103APO - Specifications

Askar 120APO - Specifications

Askar 140APO - Specifications

Askar 185APO - Specifications