Askar FRA300 Pro 60mm f/5 Quintuplet APO

The FRA300 Pro: A 60mm Astrograph for Portable Imaging

The FRA300 Pro is the first of the Askar Pro series and the brand's smallest-aperture, fastest-native-focal-ratio Petzval astrograph to date. The 60mm aperture and 300mm focal length suit large nebulae, the Andromeda Galaxy (M31) and rich star fields.

The f/5 focal ratio effectively reduces exposure time, and with the compact tube and 2.5-inch geared focuser it is the portable choice for field photographers.

Quintuplet Petzval Optics: One ED Element for Apochromatic Stars

At the heart of the FRA300 Pro is a five-element, fully air-spaced optical design. This quintuplet layout, which includes one ED (Extra-low Dispersion) glass element, is fully multi-coated to remove stray light. The central star-point RMS radius is less than 2 micrometers.

The rear group uses two far-separated lenses, which improves star quality and aberration correction and gives very good control of full-frame peripheral light fall-off. With the native Petzval design there is no separate flattener to choose and space.

300mm at f/5: Capturing Wide-Field Data in Less Time

At 300mm a full-frame camera covers about 6.8 x 4.6 degrees, enough to frame the North America Nebula (NGC 7000) or the Veil Nebula complex in one shot.

Compared with f/6 or f/7, f/5 helps you get the same exposure in less time: about 69% of the time needed at f/6 and 51% at f/7.

A Flat 44mm Image Circle, No Flattener Required

The Askar FRA300 Pro supports a 44mm image circle, which is compatible with most cameras on the market, up to full-frame format (36x24mm).

Because the Petzval design has the field flattener built-in, you do not need to purchase or calculate the spacing for an external corrector. As long as the focus is within a certain range, it is at the optimal position.

Connection Distances up to 71mm

With the focuser fully retracted, the maximum connection distance is up to 71mm from the M42 and M54 threads, and up to 67mm from the M48 thread. Plan the optical length of filter drawers or an off-axis guider within these figures.

The focuser is equipped with a universal M48x0.75 male thread adapter with a built-in 2-inch filter thread, and Askar includes separate M54x0.75 and M42x0.75 adapters for a variety of imaging equipment.

The 2.5" Focuser: Dual-Speed Control with a 360° Rotator

The FRA300 Pro has a 2.5-inch rack-and-pinion focuser that is solid and beautiful, with twin coarse knobs and a fine adjustment knob.

A 360° rotator is integrated into the rear of the focuser. It lets you rotate to any angle when shooting.

Imaging Train Integration: Pairing Cameras with the FRA300 Pro

The M48 thread and the included M42 and M54 adapters cover common camera connections.

• Sensor Compatibility: The 44mm image circle covers full-frame sensors, and smaller APS-C and Micro Four Thirds sensors use its central part.
• Filter Integration: The M48 thread at the rear of the focuser has a built-in 2-inch filter thread.
• Guiding: The multi-functional handle can take a universal Vixen-style finder base, for example for a guide scope; an off-axis guider (OAG) must fit within the connection distance.

Mechanical Design: A 303mm Tube with CNC-Machined Hardware

The Askar FRA300 Pro is assembled from CNC-machined components with a smooth spray coating and light oxidation. The optical tube assembly is 303mm long.

The single tube ring is lightweight, the multi-functional handle can take a Vixen-style finder base, and the 300mm Vixen-style dovetail plate lets the astrograph keep its balance on the mount.

Field-Ready at 3.12kg: Portability and Included Components

With a bare optical tube weight of just 2.26kg and a total weight of 3.12kg with the tube ring and dovetail plate, the FRA300 Pro is easy to take far from city lights.

The package includes a tube ring, a multi-function handle, a 300mm Vixen-style dovetail plate, and both M54 and M42 camera adapters.