Askar FRA500: A Quintuplet Astrograph Built for Serious and Beginner Imagers
Askar has been making waves in the astrophotography world with its premium refractors, and the FRA500 is a perfect example. This no-fuss quintuplet refractor is designed with the dedicated astrophotographer in mind, delivering sharp, well-corrected images without the hassle of additional flatteners. In this review, we’ll cover its design, features, and most importantly, how it performs under the stars while targeting the rich and chaotic Sadr region in Cygnus
Specifications Overview
The FRA500 is a five-element Petzval astrograph featuring two extra-low dispersion (ED) glass elements in its front group. This design delivers excellent color correction and a 55mm flat imaging circle right out of the box, no field flattener required. If you do choose to install the optional 0.7x reducer, 55mm of standard spacing is, in fact, required.
- Aperture: 90mm
- Focal Length: 500mm (native), 350mm with optional 0.7x reducer
- Focal Ratio: f/5.6 (native), f/3.9 (with reducer)
- Image Circle: 55mm native, 44mm with reducer (full-frame capable)
- Weight: ~10 lbs
The Petzval design eliminates backfocus and spacing frustrations at its native focal length. If you can achieve focus, you’ll have a flat field, and sitting at just 10 pounds, the FRA500 is portable enough for the smallest equatorial mounts on the market. Askar ships the FRA500 in a custom hard case, which is a welcome bonus, making transport safe and easy.
Build & Features
The FRA500 comes with several features appreciated by modern astrophotographers that make camera installation, framing, and focus as hassle-free as a refractor can be. Here are the notable features that make the Askar FRA500 stand out:
- 3.5" Dual-Speed Rack & Pinion Focuser with a 10:1 adjustment ratio
- Built-in Rotator with tension and locking screws for precise framing
- CNC-Machined Retro-Red Rings with D-style dovetail
- Ergonomic Handle Bar for easy transport and accessory mounting
- Adjustable Dew Shield with a matching anodized dust cap
- Wide Thread Compatibility: M48, M52, M54, and M68 adapters included
- Reducer-Ready: Includes the adapter needed for the optional Askar 0.7x reducer
Field Testing the FRA500
When we put this scope to the test, we used some of the most modern astrophotography equipment available today in order to streamline our imaging setup and maximize time under the few clear skies that we get this time of year. For this test, we used:
- Askar 0.7x Reducer
- ZWO EAF Pro (Bluetooth & battery-powered)
- ZWO Camera Angle Adjuster
- ASI2600MC Air (cooled OSC camera)
- Askar Color Magic E-Series 4nm Dual-Band Filters (Ha/Oiii and Sii/Oiii)
- ZWO AM5N Mount
Our target was the Butterfly Nebula near Sadr. This nebula can be captured during prime Milky Way season, or July and August. Using the E-Series filters, we gathered over 13 hours of exposure time using 15-minute subs over two nights. Our goal is to pair this incredible refractor and the 0.7x reducer with Askar’s 4nm Color Magic filters for a beautiful Hubble palette style image. Before we discuss the final image, let's dive deeper into the image quality produced by the FRA500.
Image Quality
First, we’ll discuss 5 minutes worth of exposure time through the FRA500 and 0.7x reducer without a filter installed. This photo is of the Sadr region and the Butterfly Nebula. With the Askar 0.7x Focal Reducer, stars remained sharp to the corners of an APS-C sensor with minimal eccentricity, which was impressive to see with such a fast focal ratio. The bright star Sadr shows no haloing effect, attesting to the precision and quality of the optics. Although we didn’t test this scope with a full-frame camera, these results suggest the reducer would still perform quite well.
Next, we have a photo of the same region but taken without the reducer at the scope's native focal length of 500mm. At f/5.6, star correction was flawless across the field of an APS-C sensor, and we have great confidence that the 55mm imaging circle would ensure excellent performance for full-frame sensors. The star Sadr was nicely controlled here as well.
Lastly, we have the final processed image of the Butterfly Nebula showcasing rich detail, vibrant narrowband color, and pinpoint stars… a testament to both the optical design and the Color Magic Filters.
Final Thoughts
The Askar FRA500 is a versatile, portable, and optically superior refractor that delivers incredible results with minimal setup headaches. Whether used at its native focal length or paired with the Askar 0.7x reducer for faster imaging, this refractor is a serious performer for deep-sky astrophotography and any astrophotographer looking for their first serious imaging telescope. If you want a refractor that’s ready for full-frame imaging out of the box and integrates seamlessly into a modern imaging workflow, the FRA500 is a top contender.
Learn More
Interested in diving deeper into the world of astronomy? Check out our AstronomyHub for a wealth of articles, guides, local resources for planetariums and observatories near you, and more to enhance your stargazing experience.
