Introducing the William Optics Redcat71: An Overview
The William Optics RedCat 71 is a new astrophotography telescope that aims to deliver high-quality imaging performance. With its all-red livery and compact tube length of just 335mm, it’s an attractive and portable option for astrophotographers.
The RedCat 71 comes in a durable and padded nylon carry-case, which meets the dimensions for airline hand-luggage. This ensures that the telescope is well-protected during transport. Its attention to detail and engineering finish is evident, with its lustrous satin crimson appearance.
One notable feature of the RedCat 71 is the incorporation of a Bahtinov mask into the lens cap. This accessory is essential for achieving sharp focusing, and its integration into the dew cap is a clever design.
The telescope’s tube assembly includes a large helical focuser barrel, which takes up 100mm of the 335mm tube length. The rubberized surface of the focuser is tactile and non-slip, with rotational tension controlled by the dew tube acting as a friction clamp. Additionally, a ribbed collar on the helical ring allows for the use of an EAF device for precise focusing.
The tube assembly terminates in a 360-degree rotating M54 thread, with M54 and M48 adapters provided. These adapters include a cell for deploying 48mm filters, and a tilt mechanism for microscopic adjustment of the imaging plane. However, it’s worth noting that the telescope does not come with photographic M42, T-mount, or C-mount adapters, which may be necessary for using imaging devices.
The RedCat 71 is primarily designed for astrophotography and does not come with any means for visual observation. Although it is possible to attach an M54 adapter and star diagonal for visual use, the lack of back-focus makes it difficult to achieve focus with eyepieces in this configuration. Alternative methods, such as attaching eyepieces directly to the male M48 adapter, can yield visual astronomy results but may not be recommended.
In terms of optics, the RedCat 71 features a new apochromatic Petzval design, comprising a doublet objective, a central floating component, and a rear corrector. This configuration provides a wide, flat field with a 45mm imaging circle, suitable for sensors up to DSLR full-frame.
The review of the telescope’s imaging performance was conducted using an Altair GP-CAM3 290c CMOS camera and full-frame Canon DSLRs. Images of the Moon revealed no discernible difference in definition between the center and edge of the imaging circle, demonstrating the flat-field focal plane of the RedCat 71. The large field of view allows for capturing wide-angle shots of celestial objects, such as the Veil Nebula and North America Nebula, in their entirety.
Focusing with the RedCat 71 is achieved through a large rubberized ring located at the midpoint of the telescope. Concerns about potential movement or vibration during focusing were alleviated by the adjustable tension on the helical focus mechanism. A Bahtinov mask integrated into the dew cap provides precise focusing assistance.
Overall, the RedCat 71 performed admirably as an astrograph, delivering high-quality widefield images. Its large tactile helical focuser also makes it suitable for terrestrial telephoto use. However, it is worth noting that potential buyers should be prepared to acquire additional imaging adapters to ensure compatibility with their equipment.
With its compact size, attractive design, and impressive imaging capabilities, the William Optics RedCat 71 is a valuable tool for astrophotographers seeking a versatile and high-performing telescope.
