SQA55 review compared to RedCat 51

Astrophotographer and YouTuber Luca, widely known as The Space Koala, recently reviewed the Askar SQA55 Quintuplet Astrograph. Designed for astrophotography and doubling as a functional photography lens, the SQA55 piqued Luca's interest as a potential 'RedCat killer,' challenging the widely popular RedCat 51 telescope. Through detailed testing, Luca highlighted the telescope’s features, performance, and overall value, sharing insights into whether it could replace the RedCat for wide-field astrophotography.

The Askar SQA55 is a flat-field Petzval design with a 55mm aperture and 264mm focal length, achieving an f/4.8 system. Luca praised its convenience, noting that its Petzval lens system ensures accurate back focus without requiring adjustment. This, combined with its dual helical focusing rings—one for rough focus and the other for precise micro-adjustments—allowed Luca to achieve pinpoint star focus with ease. Both focusers also include locking mechanisms, a critical feature for astrophotographers needing consistent focus over long exposures.

Comparing the Askar SQA55 Quintuplet Astrograph to the RedCat 51

In terms of portability, Luca appreciated the SQA55's compact design, made possible by removable dovetail and handlebar mounts. These components, which click securely into place via a rail mechanism, contribute to its adaptability as both an astrophotography telescope and a daytime photography lens. The inclusion of a diaphragm control ring, adjustable from f/4.8 to f/22, further supports its versatility as a true hybrid lens, although this feature is primarily beneficial for daytime use.

Comparing it to the RedCat 51, Luca noted several key differences. Both telescopes share similar optical designs and focal lengths, but the SQA55’s slightly larger aperture and additional features stand out. Unlike the RedCat, which uses a single-speed helical focuser and lacks a diaphragm, the SQA55 offers a double-speed focuser and full aperture control, allowing greater precision and customization. Additionally, while the RedCat requires a hex key to adjust its mount, the SQA55’s tool-free system streamlines tripod setup.

Luca also emphasized the SQA55's compatibility with full-frame cameras. A significant drawback of the RedCat 51 is its vignetting and corner star distortion when used with full-frame sensors, an issue Luca encountered after upgrading her camera. In contrast, the SQA55 boasts a fully corrected 44mm image circle, ensuring excellent edge-to-edge performance for wide-field astrophotography. This improvement alone makes the SQA55 a strong contender for astrophotographers seeking a versatile telescope that performs well with modern camera setups.

While the SQA55 has many advantages, Luca acknowledged a few potential drawbacks. The build quality, although solid, relies heavily on its quick-release mechanisms, which might not appeal to those who prefer more traditional mounting systems. Additionally, while the handlebar and dovetail mounts are included, users must supply their own Arca-Swiss plates for tripod compatibility.

The SQA55 under the stars

Testing the SQA55 under the stars, Luca was impressed by its ability to produce sharp, distortion-free images across the frame. The precise focusing system, combined with its flat-field optics, delivered excellent results. During daytime testing, the diaphragm control ring allowed for creative flexibility, though Luca admitted to being more focused on its astrophotography applications.

So officially, the SQA55 review compared to RedCat 51 - Luca's final thoughts.

Ultimately, Luca concluded that the Askar SQA55 is a worthy alternative to the RedCat 51, particularly for users with full-frame cameras or those seeking a dual-purpose lens for astrophotography and traditional photography. While it may not render the RedCat obsolete, the SQA55’s innovative features and thoughtful design make it a compelling choice in its price range.