Celestron 70AZ Refractor Telescope: What It Shows and How to Use It

Updated November 2026

The celestron 70az refractor telescope is a small, portable instrument with a 70mm objective lens and an altazimuth mount. This guide explains what that combination actually shows you in the night sky, how to set it up in about fifteen minutes, and how to pick the right eyepieces and observing targets. By the end, you should know what to expect from its views and how to avoid the mistakes that frustrate many first-time owners.

What the Celestron 70AZ Actually Shows You

A 70mm refractor gathers light through a glass objective lens rather than a mirror. Light-gathering power scales with the area of the lens, so a 70mm aperture collects roughly four times the light of a 35mm opening and noticeably more than a typical pair of 10×50 binoculars. That is enough to show the Moon in sharp detail, the four large Galilean moons of Jupiter as tiny points, the phases of Venus, and the brighter star clusters such as the Pleiades and the Double Cluster in Perseus.

Shopping for one? See our guide: Celestron Omni XLT 102mm AZ Refractor Telescope: 3 Best Picks Compared (2026).

Expectations matter. Deep-sky objects like the Orion Nebula will appear as faint gray patches with a hint of structure, not the colorful images seen in long-exposure photographs. Galaxies such as Andromeda show their bright core and perhaps a suggestion of the outer glow under dark skies. Saturn’s rings are visible and can look like a small, distinct oval, though the Cassini Division is usually not resolved at moderate magnifications.

Key specifications to know, as manufacturers typically list them:

• Objective diameter: 70mm
• Focal length: about 700mm, giving an f/10 focal ratio
• Mount: altazimuth (up-down and left-right movement)
• Typical eyepieces supplied: lower and higher power options, with the exact set varying by package

Setting Up the Telescope Step by Step

Setup on an altazimuth mount is simple, and most owners can go from box to first light in about fifteen minutes once they have done it a couple of times.

1. Choose a flat, stable spot. Avoid grass or soft soil where the tripod legs can sink.
2. Extend the tripod legs to a comfortable eye-level height and tighten the leg locks evenly.
3. Attach the mount head to the tripod and secure the central bolt firmly.
4. Mount the optical tube onto the altazimuth bracket and tighten the clamps. Check that the tube swings freely without binding.
5. Insert the lower-power eyepiece into the diagonal or focuser. Some packages use a diagonal, and others include a direct-view setup; follow the manual for your version.
6. Remove the dust cap from the front of the objective only when you are ready to observe, and keep it nearby for storage.

Collimation and Focus

Most refractors ship aligned well enough for visual use, so collimation is rarely an issue. Focus by turning the focuser knob slowly through the point of sharpness, going a little past it and then coming back. If you cannot reach focus at all, the focuser may be pulled out too far or pushed in too far, so check the travel range first.

Balancing and Movement

Loosen the altitude clamp and find the tube’s balance point on the mount. Tighten the clamps just enough to hold the tube steady. Smooth, slow hand motions give the best control at higher magnifications.

Choosing Eyepieces and Magnification

Magnification depends on the focal length of the telescope divided by the focal length of the eyepiece. With a 700mm focal length, a 20mm eyepiece produces 35x, and a 10mm eyepiece produces 70x. The practical rule is that the telescope’s useful upper limit is roughly 2x the aperture in millimeters, which places it near 140x, but most viewing on a 70mm instrument is more pleasant between about 25x and 90x.

Eyepiece focal length	Approximate magnification	Good for
25mm	28x	Wide-field views, large star clusters, the full Moon
20mm	35x	Jupiter’s moons, Pleiades, general sky sweeping
10mm	70x	Lunar craters, Saturn’s rings, double stars
6mm	117x	Tight double stars and steady nights only

Start with the lowest-power eyepiece to find your target and frame it, then step up in power. Higher magnification shows more detail only when the atmosphere is steady, and most nights will limit useful power well before the optics do.

Best Targets for Each Season

Plan your observing around what is visible rather than trying everything at once. A seasonal approach keeps sessions focused and rewarding.

• Winter: The Orion Nebula, the Pleiades, the Double Cluster, and the Moon’s terminator, where shadows reveal crater relief.
• Spring: The Beehive Cluster in Cancer, the Whirlpool Galaxy if your sky is dark, and Jupiter’s moons on favorable evenings.
• Summer: The Ring Nebula in Lyra, Albireo’s color contrast, and the star clouds of the Milky Way in Sagittarius from a dark site.
• Autumn: The Andromeda Galaxy, the Great Square of Pegasus, and Saturn when it is well placed in the evening.

Printed star charts or a free planetarium app will help you locate these targets efficiently. For more context on how refractors perform across different target types, see Celestron 90AZ Refractor Telescope: What It Shows You and How to Use It and Celestron AstroMaster 60LT Refractor Telescope: What It Shows and How to Use It, which cover neighboring aperture sizes.

Tips for Better Views

Good observing depends as much on technique and environment as on the telescope itself. Let the optics cool to outdoor temperature for 20 to 30 minutes before critical viewing, since a warm tube produces shimmering images. Use a red flashlight or dim red LED to protect your night vision and keep notes or charts readable. Observe from a site away from streetlights, and give your eyes at least 15 minutes to adapt to the dark.

Sitting on a stool or using a low chair reduces neck strain on long sessions. Keep the eyepiece clean by blowing off dust with a bulb blower rather than wiping the lens, which can scratch coatings.

Common Mistakes

• Jumping straight to high magnification. Most targets look better at lower power, and the image dims as magnification rises.
• Leaving the dust cap on the objective and then forgetting it is there during observing, which blocks all light.
• Pointing the telescope near a window or into a heated room, which causes thermal currents and blurry images.
• Expecting photographic color and detail from deep-sky objects. Visual observing shows fainter, grayer images.
• Overtightening the altitude and azimuth clamps, which can strain the mount and make smooth motion difficult.
• Viewing the Sun without a proper solar filter. Never look at the Sun through any telescope or finder unless it has a certified full-aperture solar filter fitted to the front of the instrument.

Recommended gear

A few accessories make the 70AZ easier to use and more enjoyable under the stars. For a deeper look, Celestron Astromaster 70az Lt Refractor Telescope Kit: A Practical Guide (2026) covers this in detail.

• Red-light headlamp: Preserves night vision while you adjust eyepieces and read charts. View on Amazon
• Planisphere or star chart: Helps you locate targets quickly without a phone screen. View on Amazon
• Bulb blower: Removes dust from lenses safely without touching the glass. View on Amazon
• Full-aperture solar filter: Required if you ever plan to observe the Sun, and it must fit the front of the telescope. View on Amazon

FAQ

Is the celestron 70az refractor telescope good for beginners?

Yes, for many people it is a reasonable first telescope. It is light, simple to set up, and shows the Moon, planets, and bright star clusters clearly. Expectations about faint deep-sky objects should stay realistic.

What is the highest magnification I should use?

A common guideline is about 2x the aperture in millimeters, roughly 140x for a 70mm refractor. In practice, most nights look best between 25x and 90x because atmospheric steadiness usually limits sharpness before that point.

Can I see planets with this telescope?

Yes. Jupiter shows its cloud bands and Galilean moons, Saturn shows its rings, and Venus displays phases. Planet detail is modest at this aperture, so expect small disks rather than large, richly detailed views.

Can I use it for astrophotography?

You can attach a smartphone adapter for simple lunar and planetary snapshots, but the altazimuth mount does not track the sky for long exposures. Dedicated astrophotography requires an equatorially tracking mount.

Do I need a special eyepiece?

The supplied eyepieces are enough to start. Later, you may want a wider-field eyepiece for sweeping star fields, or a higher-power one for lunar detail. Match eyepiece choice to the target.

How do I clean the lens?

Remove loose dust with a bulb blower or soft brush first. Clean remaining smudges gently with a microfiber cloth and lens cleaning fluid made for optical coatings. Avoid household cleaners and rough paper towels.

Can I look at the Sun with it?

Only with a certified full-aperture solar filter attached to the front of the telescope. Never use eyepiece-end filters or improvised materials, because they can cause permanent eye damage. If you are unsure, consult an experienced astronomy club member or a professional observatory before observing the Sun.

Conclusion

The celestron 70az refractor telescope rewards careful, patient observing. It shows the Moon’s craters, Jupiter’s moons, Saturn’s rings, and many bright star clusters with clarity that surprises many newcomers. Set it up on a stable mount, start at low power, and plan your sessions around the season. With realistic expectations and good technique, it can serve as a dependable window to the night sky.

Related reading

• Celestron Omni XLT 120mm Refractor Telescope: What It Shows and How to Use It

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