Askar 65PHQ f/6.4 Quintuplet Flat-Field Astrograph

A Portable 65mm Full-Frame Imaging Platform

The 65PHQ is engineered for the astrophotographer who needs a compact, high-correction instrument for use with lightweight mounts and travel setups. Its combination of a 65mm aperture and a 416mm focal length is ideal for capturing expansive deep-sky objects, from large emission nebulae to wide star fields in the Milky Way.

Unlike standard refractors that require separate flatteners, the 65PHQ's integrated design means you can attach your camera and start imaging once focused. This simplifies your imaging train and eliminates the complexity of calculating back focus spacing, allowing you to concentrate on capturing your target.

Quintuplet APO Optics: A 5-Element Flat-Field Design

At the heart of the 65PHQ is its quintuplet air-spaced apochromatic (APO) objective lens. This five-element optical system functions as a complete astrograph, correcting for field curvature and other aberrations across a full-frame sensor without any additional lenses.

The design incorporates two elements of Extra-low Dispersion (ED) glass to minimize chromatic aberration. Unlike the quadruplet structure of the other PHQ models, the 65PHQ is a quintuplet, and it has a fine spot diagram with tiny distortions of the peripheral stars (central RMS radius 2.5um).

416mm Focal Length at f/6.4: Wide-Field Astrophotography

The 65PHQ's 416mm focal length provides a wide field of view that can frame some of the largest objects in the night sky. When paired with a full-frame camera, it can capture the entirety of the Andromeda Galaxy (M31) or the vast expanse of the North America Nebula (NGC 7000) in a single shot.

The native f/6.4 focal ratio is a versatile balance between exposure speed and optical correction. It's fast enough to gather significant signal on faint targets in a reasonable amount of time, while still being forgiving on guiding, making it a reliable choice for imagers at all experience levels.

Native 44mm Image Circle: No Flattener Required

The standout feature of the Askar 65PHQ is its built-in field flattener, which supports a 44mm full-frame image circle, large enough to cover a full-frame (36x24mm) sensor.

This integrated correction is a significant advantage over traditional refractors. It eliminates a common source of frustration and extra cost for astrophotographers. You do not need to buy a separate flattener or calculate its back focus distance. Just attach your camera, focus, and the field is flat.

Imaging Train Connection: M68, M54, and M48 Adapters

The 65PHQ comes with M68, M54 and M48 camera adapters. The connection starts from an M68×1 male thread (130mm from its base, with the focuser fully retracted).

The included 3-piece adapter set allows you to step down from the M68 thread to M54×0.75 and finally to M48×0.75 (76mm from the base of the M48×0.75 male thread and 105mm from the M54×0.75). For added convenience, the final M48 adapter is internally threaded to accept standard 2-inch astronomy filters.

2.5-inch Focuser: 1:10 Fine Focus and 360° Rotation

Precise focus is critical in astrophotography, and the 65PHQ is equipped with a 2.5-inch rigid rack-and-pinion focuser. Its 1:10 fine adjustment allows small focus steps.

For framing your target, the focuser includes a new-type 360° rotator with scales. This allows you to rotate your camera to the orientation you want without loosening any critical connections in your imaging train. A small finder base is also attached to the focuser body for mounting a guide scope or finder scope.

Optional 0.75x Reducer: Imaging at a Faster f/4.8

For those seeking an even wider field of view and faster imaging times, Askar offers a dedicated 0.75x focal reducer designed specifically for the 65PHQ. This optional accessory transforms the telescope into a 312mm f/4.8 instrument.

Switching to f/4.8 significantly shortens required exposure times, allowing you to capture more data in a single night. The reducer is a full-frame unit with a quadruplet design. Its back focus is the standard 55mm, and it comes with M54 and M48 thread adapters with a built-in M48×0.75 2-inch filter thread.

Mechanical Design: 300mm Dovetail and Imaging-Ready Build

The Askar 65PHQ is built with the practical needs of astrophotography in mind. The tube is CNC machined and painted, and a telescopic lens hood blocks stray light. The scope is supplied with a pair of sturdy tube rings and a multi-functional handle that can be used for carrying or mounting accessories.

A 300mm Vixen-style dovetail plate is included, providing a long, stable platform for balancing the telescope on your equatorial mount. The extended length of the dovetail allows for significant fore-aft adjustment, making it easy to balance with a camera and guide scope attached.

Just 2.8kg: The 65PHQ for Travel and Lightweight Mounts

Portability is a primary design goal of the 65PHQ. The optical tube assembly (OTA) alone weighs only 2kg. The full package, including the tube rings, handle, and 300mm dovetail plate, comes in at a mere 2.8kg. This low weight suits portable mounts.

Its compact physical size is equally impressive. With the dew shield retracted and adapters attached, the scope measures as short as 360mm. This small footprint makes it easy to pack for trips to dark-sky sites and requires less counterweight on your mount, further reducing the overall weight of your setup.

Visual Astronomy with the 65PHQ Astrograph

While engineered as a photographic instrument, the 65PHQ is also a nice choice for visual observation: it fits diagonals as well as various eyepieces. Its f/6.4 focal ratio delivers bright, wide-field views that are perfect for sweeping through the star fields of the Milky Way, observing large open clusters like the Pleiades (M45), or taking in the full extent of large nebulae.

Askar adds that it can even be used to observe planets with a high-magnification eyepiece. Its light 2.8kg weight makes it an excellent "grab-and-go" telescope for quick visual sessions when you don't want to set up a larger, heavier instrument.

Askar 65PHQ vs. 80PHQ: Portability vs. Aperture

The primary advantage of the 65PHQ over its larger sibling, the 80PHQ, is its portability. The 65PHQ is lighter and more compact, making it a better match for smaller equatorial mounts and star trackers where every kilogram matters.

• Askar 80PHQ Advantage: With an 80mm aperture, it gathers more light and provides higher resolution, making it better suited for resolving detail in smaller, fainter targets.
• Askar 65PHQ Advantage: With an OTA weight of only 2kg (vs. the 80PHQ's 3.9kg), the 65PHQ is easier to mount and balance, and its 416mm focal length gives a wider field.