Askar FRA600 f/5.6 Quintuplet Astrograph APO Refractor Telescope

The Askar FRA600 is a member of the FRA (Flat-field Refractive Astrograph) series, designed for full-frame astrophotography and refined visual observing. Its 5-element Petzval-like design with two ED elements provides a naturally flat field, excellent colour correction, and crisp, round stars across a generous 66 mm image circle.

Highlights

• 108 mm aperture • 600 mm focal length • f/5.6
• Quintuplet (3+2) APO optical layout with two ED lenses for tight, colour-pure stars
• Native flat field—no external flattener or spacing maths required
• 66 mm image circle—surpasses standard full-frame coverage
• Large 4.2″ rack-and-pinion focuser with 1:10 micro-adjust and multi-thread adapters
• Portable 493 mm length (dew shield retracted), robust rings, handle, Losmandy plate
• Quality-assured mechanical finish and smooth operation under imaging payloads

Customer feedback suggests performance comparable to, or exceeding, some higher-priced alternatives—while remaining practical for portable rigs.

Watch: Unboxing & Demonstration

Optical Design & Field Correction

Like the FRA400, the FRA600 uses a Petzval-style 3+2 configuration: a front triplet (including two ED elements) manages aberrations; a rear doublet sets the focal plane and flattens the field. The 80 mm rear-group elements help maintain illumination, yielding even brightness and pinpoint stars across the frame.

Focuser, Mechanics & Rig-Friendliness

The 4.2″ R&P focuser offers coarse and 1:10 fine control, clear graduations, and multiple thread options. The standard conical extension provides M68×1, M54×0.75 and M48×0.75 connections (with 2″ filter holder), simplifying camera attachment and future-proofing your setup. Multifunction red-anodised tube rings include mounting points on three sides for guidescopes, controllers, and mini PCs.

With a tube diameter of 120 mm and a retractable dew shield, the OTA measures 493 mm retracted, making it a practical choice for travel and remote imaging.

What It’s Great For

• Full-frame deep-sky imaging with a moderate field (nebulae, clusters, smaller galaxies)
• Portable rigs where rigidity, flat field, and simplicity are essential
• High-contrast visual observing with minimal chromatic aberration

Specifications

What’s in the Box

• FRA600 OTA with retractable dew shield
• Pair of tube rings with top handle
• Losmandy-style dovetail bar
• Conical adapter set (thread converters + 2″ filter holder)
• 2″ to 1.25″ adapter (eyepiece holder)
• Instruction manual & QC inspection list

Gallery