Telescope-Refracting Telescopes-Askar FRA300 Pro Quintuplet APO Refractor

The Askar FRA300 Pro: The Most Compact of the Flat-Field Refractive Astrograph Line!

This Askar FRA Quintuplet series telescope is a premier portable astrograph designed to deliver quality flat frame images and crisp star shapes during astrophotography sessions. FRA, which stands for “Flat-Field Refractive Astrograph” provides built-in flat field correction without the need for an additional field flattener. Askar has utilized a Petzval-like quintuplet design, with one lens made of special ED glass on this 60 mm f/5 refracting optical tube with a 300 mm focal length. This eliminates the need to calculate backfocus as long as the focus is within a certain range. Using a design similar to Petzval also means the optical tube is excellent at controlling and diminishing chromatic aberration. The fully-multi coating effectively removes stray light and reduces peripheral light at full-frame. The image circle of the FRA300 Pro is 44 mm full-frame and the f/5 focal ratio helps reduce the exposure time.

The FRA300 Pro Quintuplet has a 2.5″ rack-and-pinion focuser with dual-speed hand knobs: one for coarse and the other for 1:10 fine focus adjustment. The end of the OTA is equipped with a 360° rotator so users can rotate a camera to any orientation when imaging. The focuser design is both solid and aesthetically pleasing and comes equipped with a universal M48x0.75 thread adapter. This kit comes with two additional separate adapters, an M54x0.75 adapter and an M48x0.75 adapter, making it easy to connect a variety of different user-supplied accessories.

Please note that this telescope cannot accept 2″ diagonals, however a T2 diagonal prism with a short light path and some good 1.25″ eyepieces will allow you to use the FRA300 Pro visually.

Everything Needed to Integrate the FRA300 Pro Into Your Astrophotography Setup

The FRA300 Pro refractor optical tube is assembled from high-quality CNC machined components that have a smooth spray coating and light oxidation process. Included with the 60 mm FRA300 Pro astrograph is a tube ring, red anodized to match the FRA300 Pro astrograph body. Also included is a 300 mm Vixen-style dovetail, also designed to match the OTA coloring, and a multi-purpose handle that can accept a Vixen-style finder base (sold separately). These are incredibly convenient features when it comes to the organization of your accessories and mounting your OTA to get the most out of your sessions.

Novel Quintuplet Optical Design
The Askar FRA300 Pro features optics configured in a five-element, fully multi-coated, 3+2 quintuplet design. The front lens group includes one lens made of extra-low dispersion (ED) glass to reduce chromatic and other aberrations. The back lenses are far-separated and air-spaced to improve star image quality, as well as reduce peripheral light in full-frame.

Several Helpful Accessories Included
Along with the optical tube, the FRA300 Pro comes with a tube ring with a multifunctional carrying handle. The handle can connect to a universal vixen-style finderbase (sold separately) to attach additional accessories. Also included is a vixen-style dovetail plate and three adapter rings: one M42x0.75, one M48x0.75, and one M54x0.75. Allowing for the addition of a 2″ filter is the built-in filter thread on the M48 adapter. A manual is also included.

A Flat Field Right Out of the Box!
The Askar FRA300 Pro adopts a Petzval design for exceptional astrophotography performance. This refractor accommodates an image circle of 44mm without the need for an additional field flattener, meaning full frame sensor images will have sharp stars all the way to the corners! Also, thanks to the inherent flat field of this Petzval telescope, avoid the daunting task of finding the perfect backfocus all together, letting you get out and image in no time.