Refractor Telescope Celestron Astro Master 90AZ 90mm Optical Tube

The Celestron Astro Master 90AZ 90mm Optical Tube is a refractor telescope designed for both terrestrial and celestial observation. It features a 90 mm objective lens and erect-image optics that deliver correct, right-side-up views for land use while providing bright, high-contrast views of the Moon and planets. The telescope ships with a sturdy, pre-assembled steel-leg tripod and a quick-release dovetail for fast, no-tool setup. The package also includes TheSky Level 1 planetarium software with a 10,000-object database to assist with planning observing sessions and identifying celestial objects.

Advantages

The erect-image optics make the Astro Master 90AZ suitable for daytime use as well as night observing, avoiding inverted views common to some astronomical designs. The 90 mm aperture balances portability and light-gathering ability, producing clear images of lunar and planetary detail and enabling views of brighter deep-sky objects. A permanently mounted StarPointer finder and a pan-handle Alt-Azimuth control with clutch provide straightforward targeting and smooth manual tracking. All-glass fully coated optics improve contrast and reduce reflections, while the durable tripod and deluxe accessory tray offer stable support and convenient storage.

Suitable for

• Beginner and hobbyist astronomical observation of the Moon and planets
• Terrestrial viewing such as landscapes, wildlife, and distant landmarks
• Casual backyard stargazing and family use
• Portable field observing and short public demonstrations

Key specifications

• Optical design: Refractor with erect-image optics
• Objective aperture: 90 mm
• Mount type: Alt-Azimuth with pan-handle and clutch
• Tripod: Pre-assembled steel tube legs for increased stability
• Finder: Permanently mounted StarPointer reflex sight
• Optics: Fully coated glass elements for improved contrast
• Accessories: Quick-release dovetail attachment and deluxe accessory tray
• Included software: Planetarium program with a 10,000-object database
• Approximate package weight: 9.07 kg

How to use

Set up the tripod on a stable, level surface and attach the optical tube using the quick-release dovetail. Mount the StarPointer and align it during daylight by centering a distant terrestrial object in both the finder and the main eyepiece; this alignment will also aid night-time pointing. Use the pan-handle Alt-Az control to point the telescope and tighten the clutch for smooth manual tracking. Start observing with a low-power eyepiece for a wider field of view, then increase magnification to examine lunar and planetary details. Use the included planetarium software to locate objects and plan observing sessions.

Usage recommendations

For best optical performance, allow the telescope to reach ambient temperature before high-magnification viewing. Use the erect-image optics for daytime terrestrial observation and switch to night-time use for lunar and planetary viewing. Clean lenses sparingly using a soft brush or air blower and a lens cloth to avoid damage to coatings. When transporting, secure the optical tube to the tripod with the quick-release dovetail and protect optics with caps.