Explore Scientific FirstLight 90mm Doublet Refractor with AZ Mount - Discontinued
- 90mm Achromatic Doublet Refractor
- 500mm Focal Length (f/5.5)
- Manual Alt-Azimuth Yoke Mount
- Includes 9mm & 20mm Kellner Eyepieces
- Smartphone Camera Adapter Included
The Explore Scientific FirstLight 90mm Doublet Refractor combines a 90mm aperture with a 500mm focal length for impressively wide fields of view. This fast f/5.5 optical system is packaged with 9mm and 20mm eyepieces, a stable alt-azimuth mount, and a smartphone adapter, creating a complete system for observing the Moon, planets, and bright deep-sky objects.
At the heart of this telescope is a 90mm air-spaced achromatic doublet objective lens. The fully multi-coated optics maximize light transmission for bright, contrast-rich images of everything from lunar craters to star clusters. The fast f/5.5 focal ratio creates a vast field of view, perfect for scanning the Milky Way or framing large objects like the Andromeda Galaxy (M31) or the Orion Nebula (M42).
While this design delivers excellent wide-field views, the trade-off for a fast achromat is minor chromatic aberration (false color) on the brightest targets like Jupiter or Venus. This is a normal characteristic of this optical design and is well-controlled for its intended use.
Designed for simplicity, the FirstLight 90mm includes a manual alt-azimuth yoke mount. This grab-and-go setup allows you to point the telescope up, down, left, and right, making it easy for anyone to begin navigating the night sky. A slow-motion altitude control rod enables fine adjustments, which is critical for smoothly tracking planets as they drift across the field of view at higher magnifications.
The mount is supported by a full-size aluminum tripod that provides a stable foundation, minimizing vibrations for steadier views. An integrated accessory tray keeps your eyepieces and other items organized and within reach during observing sessions.
This package includes everything you need for your first night out. You get two Kellner eyepieces, a 20mm for low-power, wide-field observation and a 9mm for higher-magnification views of planets and the Moon. The included red dot finder helps you aim the telescope, and an erect-image diagonal provides correctly oriented views, making the scope equally useful for daytime terrestrial observation.
For those looking to capture their discoveries, the included smartphone adapter allows you to secure your phone to the eyepiece. This setup makes it easy to take your first images of the lunar surface or bright planets, sharing the view with friends and family.
Many beginner telescopes feature a 70mm aperture, which provides a great introduction to the sky. However, the FirstLight's 90mm objective lens represents a significant step up in light-gathering ability. This increase in aperture directly translates to brighter images and better resolution.
The FirstLight 90mm is a capable instrument for a wide range of celestial objects. You can expect detailed views of the Moon's craters and mountains, the rings of Saturn, the primary cloud belts of Jupiter and its four Galilean moons, and the phases of Venus. It will also show you dozens of bright star clusters like the Pleiades (M45), nebulae like the Orion Nebula (M42), and the Andromeda Galaxy (M31) from a dark sky location.
No, this telescope is designed for beginners. The alt-azimuth mount is intuitive—simply move it up, down, left, and right to point at your target. Assembly is straightforward and typically takes less than 20 minutes. The included red dot finder makes aiming the telescope much easier than a traditional finderscope.
Using the 9mm eyepiece, you will achieve about 56x magnification. This is enough to clearly see Jupiter as a distinct disk, resolve its two main equatorial belts, and track the four bright Galilean moons as they orbit the planet. On nights with steady air, the view will be sharp and detailed.
Yes. The telescope comes with an erect-image diagonal, which corrects the view to be right-side-up and left-to-right correct. This makes it an excellent scope for long-distance terrestrial viewing, such as birdwatching, whale watching from a coast, or enjoying scenic landscapes.
The primary benefit of a "fast" f/5.5 focal ratio is a wide true field of view. This makes it easier to find objects and allows you to see large star clusters or nebulae in their entirety within a single view. This is a significant advantage over longer focal ratio telescopes, which have a more "zoomed-in" perspective.
Absolutely. The Moon is the best target to start with. The smartphone adapter holds your phone's camera steady over the eyepiece, allowing you to take surprisingly detailed and sharp photos of lunar craters and seas, especially when using the lower-power 20mm eyepiece.
| GTIN | 8122570183906 |