Explore Scientific · Achromat Refractor
Explore Scientific AR 80/900
Classic refractor performance at a beginner-friendly price, with a long focal length made for steady planetary views.
Price updated Mar 22, 2026
Performance Scores
Overview
The Explore Scientific AR 80/900 is an 80mm achromatic refractor with a 900mm focal length and an f/11.25 focal ratio, a combination that favors planetary and lunar observing. The long focal length reduces the field of view but delivers tighter, higher-contrast images of the Moon, Saturn, Jupiter, and double stars, which is exactly where this scope earns its keep. The included 25mm Plossl eyepiece gives you 36x magnification to start, and the slow focal ratio means you can push magnification higher with shorter focal length eyepieces while keeping image quality manageable.
Being an achromat rather than an apochromat, some chromatic aberration is present, particularly on bright objects like the Moon and Venus. It is not severe at f/11.25, but worth knowing before you buy. The EXOS Nano equatorial mount adds tracking capability, which helps noticeably at higher magnifications.
At just over 10kg total, it is portable but not ultralight. The 40mm focuser draws tube handles standard 1.25-inch accessories, and the included 90-degree diagonal makes viewing more comfortable at typical sky angles. For a beginner wanting a capable grab-and-go planetary setup without a large investment, this is a solid choice.
At a Glance
80mm
Aperture
f/11.25
Focal Ratio
10.32kg
Weight
900mm
Focal Length
Specifications
Key Features
- 80mm aperture at f/11.25 delivers sharp, high-contrast views of the Moon and planets
- 900mm focal length makes higher magnification eyepieces easier to use effectively
- EXOS Nano equatorial mount supports manual tracking to keep objects centered at high power
- Included 25mm Plossl and 90-degree diagonal let you observe right out of the box
- Achromatic design keeps cost down, with minimal chromatic aberration at this focal ratio
- Red dot finder makes locating targets straightforward for beginners
- Under $330 makes this one of the more affordable equatorial refractor packages available
Customer Reviews
1 reviews
Great optics on this scope with plenty of light gathering power. The included 25mm super plossl is one of my favorite eyepieces. The mount is a little bit light for this scope, with some heavy wobble from focusing. It calms down pretty quickly though