The Askar FRA300 Pro is the latest in the Askar FRA line of short focal ratio astrographs.
The Askar FRA300 Pro, is the smallest 60mm F/5 Petzval astrograph with the fastest native focal ratio in the FRA series with a focal length of 300mm. At the center of its field of view, the RMS radius can reach 2um.
The FRA300 Pro offers excellent full-frame performance and supports 44mm imaging. Compared with f/6 or f/7, F/5 can effectively reduce the exposure time, helping you get the same exposure in less time. In addition, the entire OTA is compact, making it the portable choice for field photographers.
The FRA300 Pro ‘s objective lens adopts a quintuplet fully air-spaced structure, including one piece of ED glass. It also adopts a fully-multi-coating to effectively remove stray light. In particular, the rear group lens adopts the two pieces of far-separated refractive lenses, which improves both the star quality and the aberration correction performance, and has a very good control of full-frame peripheral light reduction. Thanks to the native Petzval design, the user does not need to calculate the backfocus, as long as the focus is within a certain range in the optimal position.
Mechanically, the Askar FRA300 Pro is assembled with high-quality CNC-machined components, wrapped with smooth spray coating and light oxidation process, both beautiful and practical. The tube ring design is equally lightweight and stylish.
The focuser is a solid 2.5″ rack-and-pinion focuser which is designed with dual-speed hand knobs, twin knobs for coarse adjustment and a fine adjustment knob to accurate the focus, equipped with a universal M48X0.75 thread adapter. There are also two separate M54X0.75 and M48X0.75 adapters in the standard kit for easy access to a variety of imaging equipment and accessories. The end is equipped with a 360 degree rotator, which is convenient for users to rotate at any angle when shooting.
FRA300 Pro also comes standard with a multi-function handle and a 300mm vixen-style dovetail plate, which can be directly connected to various mounts and accessories. The multi-functional handle can also be connected to the universal vixen-style finder base. The 300mm dovetail plate allows the astrograph to maintain balance on the mount.
The Askar FRA300 Pro specifications include:
– Aperture size: 60mm
– Focal length: 300mm
– Focal ratio: f/5
– Objective len: Quintuplet fully air-spaced Petzval APO (including one ED glass)
– Image circle: 44mm full-frame
– Maximum accessory connection (with the focuser fully retreated) in imaging mode: 71mm (from the base of M42×0.75 male thread); 67mm (from the base of M48×0.75 male threadand ; 71mm (from the base of M54×1male thread)
– Total length: 303mm
– Net weight: 2.26kg
– Gross weight: 3.12kg
– Rear-end thread: M48*0.75 male thread
You can learn more about the Askar FRA300 Pro here.
And to make it easier for you to get the most extensive news, articles and reviews that are only available in the magazine pages of Astronomy Technology Today, we are offering a 1 year magazine subscription for only $6! Or, for an even better deal, we are offering 2 years for only $9. Click here to get these deals which only will be available for a very limited time. You can also check out a free sample issue here.