Askar 120 mm f7 Triplet APO - EDT Design - 3.5 inch RAP focuser - with optical test

Askar 120APO - 120 mm f/7 apochromatic refractor - EDT design

The aperture of 120 mm 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. The aperture area of the Askar 120APO enlarged by 36% compared to that of the 103APO.

Along with the more light coming into the astrograph, the limiting magnitude can reach 12.2.

The Askar 120APO has an air-spaced triplet EDT objective with ED glass. This results in a high-contrast image.

The Askar EDT (ED triplet) APO series uses 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

The Askar 120APO is light and compact with a total weight of 6.5 kg (including the tube rings). This makes it suitable for mobile use.

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

The retractable design of the dew shield and the enlarged locking screws make it easy to use. The dew shield protects the objective lens from external and internal light influences as well as protecting the objective 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, Askar has fitted special finder shoes on both sides of the focuser. This not only eliminates the need to disassemble the finder scope when changing the position of the finder, but also provides additional mounting positions for other astronomical accessories.

The handle of the Askar 120APO has a special slot design, making it also a base for installing a finder scope. The handle itself has been extended by 60 mm, which makes it easier to attach the astrograph to the tube rings.

The total weight of the tube ring is only 780 g. The knurled screws allow easy opening and locking of the tube rings. At the same time, the base of the tube rings is raised, providing more space.

The Vixen standard dovetail bar is compatible with most equatorial mounts and bases on the market. Its length has been extended and screw holes have been added so that the plate is now 290 mm long, which makes it easier to balance on the mounts. The elongated hole on the handle can be used to adjust the distance between the tube rings as desired. Additionally, there is also a Losmandy dovetail plate available for purchase, which can be used with various equatorial mounts.

Helpful optical options

There are (currently) two optional accessories for the Askar 120APO: a 1x flattener and a 0.8x reducer. Both of them have built-in filter threads which allow direct filter mounting. They are also equipped with M54/M48 adapters, which are suitable for attaching accessories.

The 1x flattener does not change the telescope´s focal ratio itself. After connecting with the Askar 120APO, it still retains 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 gives the OTA a wider field of view and shorter exposure times, making it suitable for capturing large areas of nebulae, star clusters, and faint, fast-moving celestial objects.

For visual observation, the Askar 120APO places great emphasis on observation quality. It can be easily focused when 1.25" or 2" star diagonal mirrors or various eyepieces are attached. Due to the segmented objective tube, binoviewers can also be attached for visual observation.

Quality focuser

The Askar 120APO is equipped with a stiff 3.5" dual-speed rack and pinion focuser, which is compatible with most motorized focusers on the market. A high-precision scale is placed on the 10 cm focusing travel. The entire focuser is CNC-machined and internally coated with an anti-reflective coating that provides additional measures to eliminate stray light.

The rear of the focuser features a large 360° precision rotator with accurate scales for convenient adjustment and storage of rotation angles, allowing precise rotation. It is also equipped with an enlarged locking screw for the rotator, which can be easily locked even under heavy loads.

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 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.

Let the Askar 120APO accompany you in exploring the magnificent landscapes of the universe and create unforgettable memories. Take action now and start your astronomical adventure with the Askar 120APO!

This is how we hand over the apo to the stargazer:

Every single APO is checked in our technical department before it is put into storage in order to guarantee consistently high product quality.

The mechanics are tested and the focuser is optimally adjusted.

The lens is cosmetically checked and cleaned. We also check that all counter screws are correctly tightened. These often loosen during transportation.

The optics are collimated and the result is checked on the optical bench. The telescope is given a serial number.

An optical test is carried out, which is enclosed with the telescope (star images and ronchi image on the optical bench in autocollimation).

Only then are the telescopes handed over to the warehouse and prepared for dispatch.

Technical Information

Teleskop-Service has collected a lot of helpful information about refractors and provided it in English as a PDF file: refractors.pdf

Safety informations: PDF Download