Askar 120APO Triplet APO Refractor Telescope

The Askar 120APO is a premium 120mm aperture, f/7 triplet air-spaced apochromatic refractor designed and manufactured by Askar (Jiaxing Sharpstar Optical Instrument Co., Ltd.). Built specifically for serious astrophotography and high-quality visual observation, the 120APO brings together large-aperture optics, a purpose-built imaging focuser, and a robust mechanical package — all in a surprisingly portable form factor. With a focal length of 840mm and a limiting magnitude of 12.2, this telescope is engineered to capture deep, detailed images of galaxies, nebulae, and star clusters.

Who Is This Product Best For?

The Askar 120APO is ideal for intermediate to advanced astrophotographers who want a large-aperture APO refractor capable of illuminating full-frame sensors. It suits:

• Deep-sky imagers pursuing nebulae, galaxy clusters, and extended DSOs
• Dual-use users who want both a serious imaging platform and a capable visual telescope
• Portable observatory builders who need a high-performance instrument that doesn't require a massive mount
• Visual observers seeking a wide-field, colour-corrected view of the night sky through 1.25" or 2" eyepieces or a binoviewer

This is not a beginner scope — it is best suited to users who already have experience with equatorial mounts and astrophotography workflows.

Why Choose This Product?

• 120mm f/7 triplet APO optics with one element of ED glass for outstanding chromatic aberration correction
• 36% larger aperture area than the Askar 103APO — more light, more detail, more contrast
• Limiting magnitude of 12.2 — revealing objects invisible to smaller refractors
• 3.3" dual-speed rack-and-pinion focuser with 1:10 fine-focus ratio and 10cm of travel — smooth, precise, and rock-solid under imaging loads
• 360° high-precision rotator with locking scale markings — frame your target without touching the mount
• Two-section segmented lens tube — rear section detaches for binoviewer use
• Two finder scope bases (one on each side of the focuser) for flexible accessory mounting without disassembly
• 290mm extended Vixen dovetail plate compatible with virtually all equatorial mounts; optional Losmandy plate available
• Retractable dew shield with enlarged CNC locking screws for fast, tool-free operation
• Total weight of just 6.5kg (including tube rings and dovetail) — portable enough for field use
• EAF-compatible focuser — ready for motorized autofocus
• Unique identification name ring on every unit
• Optional 1x flattener and 0.8x reducer available separately for full-frame flat-field imaging or wider, faster coverage

Recommended Uses

• Deep-sky astrophotography with monochrome or one-shot colour cameras (APS-C and full-frame)
• Narrowband imaging of emission nebulae, supernova remnants, and HII regions
• LRGB and SHO filter imaging setups
• Galaxy and star cluster photography where resolution and contrast are critical
• High-quality visual observing with 1.25" or 2" eyepieces or a diagonal
• Binoviewer use (rear tube section detaches to achieve correct backfocus)
• Motorized autofocus with ZWO EAF and compatible focuser motors
• Dual-scope or guide scope setups — dual finder bases allow flexible mounting

Compatibility and Accessory Notes

• Rear thread: M84 female thread; includes 2"/1.25" visual adapters
• Optional flattener: Askar 120APO 1x Full-Frame Flattener — maintains f/7, corrects field curvature and coma, includes built-in filter threads and M54/M48 adapters
• Optional reducer: Askar 120APO 0.8x Full-Frame Reducer — brings focal ratio to f/5.6 for faster imaging; includes field flattening, built-in filter threads, and M54/M48 adapters
• Dovetail: 290mm Vixen-style standard; Losmandy dovetail optional
• Motorized focuser: Compatible with ZWO EAF and most third-party motorized focusers
• Binoviewer compatibility: Rear tube section detaches to achieve correct backfocus for binoviewers
• Camera compatibility: Suitable for APS-C and full-frame sensors (with flattener or reducer)

Important Limitations

• A dedicated field flattener or reducer is recommended for full-frame astrophotography — the bare OTA may exhibit field curvature at the edges on large sensors
• Requires an equatorial or GoTo mount rated for at least 10–15kg payload for astrophotography; alt-az mounts are suitable for visual use only
• This is an advanced instrument — not recommended for first-time telescope buyers without prior astrophotography experience
• EAF motorized focuser, Losmandy dovetail, filters, and reducers/flatteners are sold separately
• The optional reducer/flattener accessories use M54/M48 threads — confirm your camera adapter compatibility before purchasing

Frequently Asked Questions

Is the Askar 120APO good for beginners?
Not ideally. This telescope is best matched to intermediate or advanced astrophotographers who are already comfortable with equatorial mounts, imaging software, and polar alignment. Beginners will find better value in a smaller, more forgiving APO.

What is the Askar 120APO best used for?
It excels at deep-sky astrophotography — especially nebulae, galaxies, and star clusters. It is also a capable visual telescope for those who want a premium refractor experience.

Do I need a flattener or reducer for astrophotography?
For APS-C sensors, the bare OTA often performs well. For full-frame sensors, the optional 1x flattener is recommended to eliminate edge field curvature. The 0.8x reducer is ideal when you want a wider field of view and faster f/5.6 exposures.

What mounts is it compatible with?
The included 290mm Vixen dovetail plate fits most equatorial mounts. An optional Losmandy dovetail is available for heavier-duty mounts. Look for mounts with at least a 10–15kg imaging payload capacity.

Can I use it for visual observing?
Yes. The 120APO accepts 1.25" and 2" diagonals and eyepieces, and the segmented tube allows binoviewer use. It is a capable and pleasurable visual instrument, not just an imaging platform.

What makes it different from the Askar 103APO?
The 120APO has 36% more aperture area than the 103APO, pushing the limiting magnitude to 12.2. The 3.3" focuser is larger and more rigid, and the overall mechanical package is designed for heavier imaging loads.

Is motorized autofocus supported?
Yes. The focuser is designed for compatibility with ZWO EAF and most third-party electronic autofocusers. EAF is sold separately.

Our Recommendation

The Askar 120APO is one of the most well-rounded large-aperture refractors available in its price class. It delivers true apochromatic correction, a premium imaging focuser, and a thoughtful mechanical design in a package that's still portable enough for field use. If you're an intermediate or advanced astrophotographer looking to step up to a 120mm APO platform with serious full-frame capability, the 120APO is an outstanding choice. Pair it with the optional 1x flattener for clean flat-field images, or the 0.8x reducer for a wider, faster setup. Not recommended for beginners or those without a suitable equatorial mount.

Optical Diagram Reports

The following optical reports and technical diagrams are provided by Askar for the 120APO: