Askar 103APO Refractor Telescope: A Leap Forward?
Askar 103 APO is a Triplet air-spaced refractor telescope.
We all dream of finding the perfect telescope that strikes a balance between affordability, optical performance, and versatility. The Askar 103APO promises to be that dream telescope for every astrophotographer. But does it live up to the expectations?
With a native focal length of 700mm, which can be reduced to 480mm using the dedicated reducer, the Askar 103APO sets its sights high. This telescope is the smallest in their 5 APO series, starting with a 103mm aperture and extending up to 203mm, boasting a remarkable focal length of 1421mm and a native focal ratio of f/7.
User Interface
Askar 103APO comes with several mounting bases that allow plenty of space for accessories.
The UI is arguably the most important aspect of the Askar 103APO: its incredible attention to detail.
Small touches here and there may not directly improve the final image quality but certainly enhance the user experience. For instance, the top handle also doubles as a base for installing a finderscope and other accessories. Additionally, two extra finder bases mounted on the focuser allow users to attach more accessories, while built-in 2" filter threads in the field correctors’ design make the setup even more user-friendly. These thoughtful features eliminate the hassle of figuring out where to install your finderscope, mini PC, or power distribution unit, reducing the need for extra mounting bases.
The Askar 103APO also features a 360° high-precision field rotator with detailed scales for fine-tuned adjustments, making it much easier to frame your images precisely.
The inside of the Askar 103APO's dew shield is lined with matting felt, while the main tube’s interior walls are coated with anti-reflective paint and equipped with internal baffles. These enhancements effectively reduce light scattering and internal reflections, boosting the brightness, contrast, and resolution of your observed targets.
All these features come packaged in a sturdy and stylish carrying bag that feels premium. It’s perfect for transporting the telescope, especially if exploring dark astronomy sites is part of your astrophotography routine.
Solar Corona by Uri Darom, captured with Askar 103APO
Field Correction Options
The 103APO comes with 3 optional field correctors, one flattener and two reducers (x0.8 and x0.6).
“The purpose of using field correctors is to fix field curvature and coma, resulting in flatter field edges and finer star points.”
The Askar 103 APO comes with three optional field correctors: a 1.0x flattener, a 0.8x reducer, and a 0.6x reducer.
The 1.0x field flattener preserves the telescope's native focal ratio of f/6.8. When connected to the Askar 103APO, it maintains a focal length of 700mm. It performs well with full-frame camera sensors, requiring very minimal cropping to eliminate slightly imperfect star shapes in the corners.
This flattener uses a triplet design and supports a 44mm full-frame image circle, all in a solid, hefty build, weighing 0.58 kilograms. The back focus from the M48 thread is a standard 55mm. At the camera end, it comes equipped with both M54x0.75 and M48x0.75 adapters, offering convenient connectivity. Additionally, it features a built-in 2-inch filter thread for added versatility.
Askar’s dedicated field flattener performs exceptionally with full-frame cameras
Dedicated 1x Field Flattener Diagram
The 0.8x reducer lowers the telescope's focal ratio to f/5.4, reducing the focal length to 560mm when paired with the Askar 103APO. It delivers good performance with full-frame sensors, though some cropping may be required to remove slightly imperfect star shapes in the corners.
Like the flattener, the 0.8x reducer also adopts a triplet design and supports a 44mm full-frame image circle. It is slightly lighter, weighing 0.48 kilograms. The back focus from the M48 thread remains a standard 55mm, and it is similarly equipped with M54x0.75 and M48x0.75 adapters for convenience. The built-in 2-inch filter thread further enhances its functionality.
Askar 103APO has 3 optional field correctors.
The 0.6x reducer, weighing nearly 1kg, reduces the focal length to 420mm with an impressive focal ratio of f/4. This highlights the incredible versatility of the Askar 103APO, with dedicated field correctors allowing the telescope to cover a wide range of focal lengths from 420mm to 700mm.
Installing the Askar 0.6x reducer requires an additional step: removing the tube between the OTA and the focuser. This adjustment provides the necessary length to achieve the f/4 focal ratio, transforming the telescope into a more compact design.
The 0.6x reducer employs a quadruplet optical system for enhanced performance. While Askar claims it supports a 44mm full-frame image circle, our testing revealed this is not entirely the case. The reducer struggles to fully correct star shapes in the corners, requiring approximately 15-20% of each side of the frame to be cropped.
Askar 103APO performs impressively in relation to chromatic aberration.
Optical performance
In this design, Askar uses ED glass, also known as low-dispersion glass, a type of optical material specifically engineered to reduce chromatic aberration. The results are truly impressive. Even with a one-shot color camera, there is no noticeable chromatic aberration. Additionally, the optical system is completely free from star pinching and dispersion.
Chromatic aberration is a common optical issue that causes colour fringing around the edges of objects, particularly stars, and becomes more apparent at high magnification. Apochromatic telescopes address this problem by utilising advanced optical designs and multiple lens elements to correct chromatic aberration, naturally providing superior object detail and color accuracy.
Optical Path Diagram
Things to love about Askar 103APO:
Attention to details (extra mount bases, 360° scales on the rotator and built-in 2" filter threads).
Outstanding performance with full-frame sensors.
Incredible build quality overall.
Large dual-speed rack and pinion large 3.3-inch focuser.
Relatively lightweight at 4.75 kg for the OTA.
Three exciting options for field correctors.
Things that could be improved:
The carrying bag doesn’t have additional space or pockets for accessories.
The 0.6x reducer is unable to provide a flat field all the way to the corners while using a full-frame camera. That won’t be a problem if you are using a camera with APS-C or smaller sensor size.
Key Stats:
Aperture size: 103mm
Focal length: 700.4mm
Focal ratio: f/6.8
Objective lens: Triplet air-spaced APO (including one ED glass)
Total length: 600mm（when the dew shield is contracted）
711mm（when the dew shield is stretched）OTA weight: 4.75kg
Gross weight（including tube ring and dovetail plate）: 5.5kg
Rear-end thread type: 2"/1.25" visual adapters
Standard package items: a 103APO OTA, a pair of tube rings, a handle, a 290mm Vixen dovetail plate, a manual, an Oxford cloth case.
The carrying case for Askar 103APO is included.
What’s next for Sharpstar?
This is a critical question. SharpStar has gone from strength to strength. Their hugely popular hyperbolic Newtonian reflector telescopes firmly established the company as a credible telescope manufacturer with astrophotography at the heart of its business model.
With several new product lines, including the SQA series, SharpStar is shaping an exciting future for astrophotographers. So far, they have successfully delivered high-quality telescopes at more competitive prices than many of their rivals. However, aiming high and maintaining such an ambitious outlook presents a significant challenge.
The question remains: can they continue to innovate and produce premium-quality telescopes with great optical performance while keeping their prices competitive? This ethos has defined SharpStar so far, and they’ve pulled it off to a degree. But in an increasingly competitive market, maintaining innovation, high design standards, and user-friendly interfaces at affordable prices is no small feat.
If SharpStar can sustain this balance, the future looks incredibly bright for them—and for astrophotographers worldwide.
Askar’s SQA series promise high-quality quintuplet air-spaced SD glass.
About Sharpstar Optics:
Jiaxing Sharpstar Optical Instrument Co. Ltd. was founded in 2000 in Jiaxing, Zhejiang, China. They are specialised in research, development and production of astronomy instruments.
Sharpstar brand is divided into refractors and reflectors as well as mounts and tripods. And under the Askar brand there are SQA series, PHQ series, FRA series, APO series, FMA series, V series, F series as well as filters and accessories.
