Askar 185 mm f/7 Triplet Apo - EDT Design - 3.5 inch RAP focuser - with optical test

Askar 185 mm f/7 Triplet Apochromat - EDT Design - 3.5 inch RAP focuser

As a large aperture refractor, Askar 185APO fills the market vacancy, continues the high quality and cost-effectiveness of APO series telescopes, and provides a new choice for astronomical amateurs.

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin

The Askar 185APO is a telescope with 185 mm aperture, 1295 mm focal length, and f/7 native focal ratio

The large aperture of 185 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. Along with more light coming into the astrograph, the limiting magnitude can reach 13.1.

The Askar 185APO 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.
As a large aperture, long focal ratio telescope, the Askar 185APO was designed with portability in mind. The shortest overall length is only 1081 mm, the net weight is 14.9 kg, and the gross weight is 17.2 kg (including the handle, tube ring, and dovetail plate).

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 185APO 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 185APO has a special slot design, making it also a base for installing a finder scope. The handle itself is 400 mm long.
The dovetail plate of the Askar 185APO 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 400 mm, which is easier to balance on the mounts. With the slotted handle, the spacing between the tube rings can be adjusted as desired.

Integrated tube extension

It is worth mentioning that the rear lens tube of the Askar 185APO 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 185APO can be used with a binoviewer for visual observation. When the lens tube is stretched, the 185APO 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.

The focuser of the 185APO

In terms of the focuser, the Askar 185APO is equipped with a large, rigid, 3.5-inch dual-speed rack and pinion focuser, which is compatible with most motorized focusers on the market. There is a high-precision scale on the drawtube with 10 cm 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 big 360° high-precision 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 185APO 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.

Accessories: 0.8 reducer and 1.0 flattener

The Askar 185APO 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 185APO, 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 185APO´s focal ratio 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.

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

Every single 185APO is checked in our technical department before it is put into storage, in order to guarantee a 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

Image by a customer

Our customer Thomas Dahmen took a picture with this telescope and the 1x flattener, which we are happy to show here:

Object: Leo Triplet (M 65, M 66, NGC 3628)

Photographer: Thomas Dahmen
Telescope: 185 mm f/7 Triplet Apo (AS185APO)
Flattener: Askar 1.0x corrector for the 185 mm f/7 triplet APO (ASFLAT-185)

We congratulate Thomas Dahmen on this impressive picture!

Safety informations: PDF Download