National Geographic 70 Computerized Refractor Telescope: Setup and Use Guide

Updated November 2026

The National Geographic 70 computerized refractor telescope is a small, goto-equipped scope built around a 70mm objective lens. In this guide you will learn how to unpack it, set up the tripod, align the computerized mount, make your first observations and get more out of the optics. Along the way you will see what a 70mm refractor realistically shows you, from the Moon and planets to bright star clusters, and where its limits lie.

What the National Geographic 70 Computerized Refractor Telescope Does Well

A 70mm refractor gathers a modest amount of light, so it will not reveal faint galaxies the way a larger reflector can. Where it shines is in bright, high-contrast targets. The Moon is the obvious first target, and at moderate magnification you can pick out craters, the terminator line where sunlight meets shadow, and the broad maria. Jupiter shows its cloud belts and the four Galilean moons as small points of light, and Saturn’s rings are visible as a clear oval once the scope is focused well. Bright double stars, the Pleiades and the Orion Nebula are also rewarding.

Shopping for one? See our guide: Top 6 APO Refractor Telescopes for Astrophotography Compared (2026).

Refractors have a sealed optical tube with no central obstruction, which means planetary and lunar detail tends to look crisp with good contrast. The computerized mount adds convenience by slewing the telescope to thousands of catalog objects after a short alignment. Manufacturers typically specify the tube length and focal ratio in the product documentation, so check your manual for the exact figures before buying accessories.

Tools and Items You Will Need

Most of what you need comes in the box, but a few extras make the first night far smoother:

• A flat, stable spot on grass, pavement or a deck, away from streetlights
• A red-filtered flashlight or a headlamp with a red mode, so your eyes stay dark-adapted
• The supplied eyepieces, plus a planetary-grade eyepiece if you have one
• A lens cloth for the eyepiece and objective, plus a blower to clear dust
• Fully charged batteries or a compatible power source for the computerized hand controller
• A printed or phone-based star chart for cross-checking targets

Step 1: Unpack and Assemble the Tripod and Tube

Set the tripod on level ground and extend each leg to a similar height. Tighten the leg locks firmly, because a wobbly tripod will ruin high-power views. Attach the center column or accessory tray as the manual describes, then mount the optical tube to the mount head. Tighten the dovetail or clamp screws until the tube cannot rotate or slide under its own weight.

1. Extend the tripod legs evenly and lock them.
2. Attach the mount head and tighten the hardware.
3. Slide the optical tube onto the mount and secure it.
4. Install the diagonal, then insert an eyepiece and tighten its set screw.
5. Remove the lens cap only when you are ready to observe.

Step 2: Power On and Set the Mount

Power the hand controller and the mount. Most computerized mounts of this class ask you to set the date, time and location. Enter your latitude and longitude carefully, or select your city from the built-in list. An incorrect location is one of the most common reasons alignment fails. Set the time in local time and confirm daylight saving settings if the controller asks for them.

Next, level the tripod as closely as you can by eye. Many setups use a bubble level on the mount head. Accurate leveling helps the goto system find objects more reliably, though you will correct for small errors during alignment.

Step 3: Perform the Alignment

Alignment tells the computer where the sky is relative to the telescope. Most computerized refractors use a one-star or two-star alignment. You select a bright star from the list, center it in the eyepiece using the directional buttons, and confirm. For a two-star alignment, you repeat the process with a second star far from the first across the sky. Wider separation between alignment stars generally produces better goto accuracy.

Alignment Method	Stars Needed	Typical Accuracy Benefit
One-star	1	Adequate for nearby targets; drifts more over long sessions
Two-star	2	Better overall pointing, especially when stars are well separated

Choose alignment stars that are bright, unobstructed and in different parts of the sky. Avoid stars near the horizon, where atmospheric distortion makes centering harder.

Step 4: Find and Observe Your First Targets

Start with the Moon. It is easy to find, bright enough to forgive small pointing errors, and rewarding at both low and medium power. Use the lowest-power eyepiece first to center and frame the target, then switch to a higher-power eyepiece for detail. Focus slowly, moving the focuser back and forth until the image is sharpest.

After the Moon, try Jupiter or Saturn if they are up. Planets reward patience. Give your eyes a few minutes to adjust, and let the image settle when the air is steady. The scope may show more detail on nights with calm air, sometimes called good seeing.

For deep-sky objects, begin with the brightest and largest: the Orion Nebula, the Pleiades and the Double Cluster in Perseus. Use a low-power eyepiece, since a wide field makes these large objects easier to see. Expect soft, grayish patches for nebulae rather than the colorful photographs you may have seen online. Refractor views of deep-sky objects are subtle, and they improve as your eyes adapt over 15 to 20 minutes in the dark.

Step 5: Get More from Your Eyepieces

Magnification equals the telescope’s focal length divided by the eyepiece’s focal length. A longer-focal-length eyepiece produces lower power and a wider true field, while a shorter one produces higher power and a narrower field. Lower power is better for most deep-sky work and for finding objects. Higher power suits the Moon, planets and tight doubles, though pushing magnification too far makes images dim and blurry.

A common rule is to avoid magnifications beyond roughly twice the objective diameter in millimeters, which for a 70mm scope is about 140x as a practical ceiling. Real-world limits depend on atmospheric conditions, and most nights you will get better results well below that number.

Common Mistakes

• Wrong location or time settings. Goto fails badly when the date, time or site is off. Double-check them before every session.
• Alignment stars that are too close together. Spread them across the sky for better pointing.
• Using high power too early. Start low, center the target, then increase magnification.
• Touching the tube while focusing. Vibration blurs the image. Focus gently with the knob.
• Observing near city lights. Light pollution washes out faint objects, so a darker site helps even a small refractor.
• Forgetting dark adaptation. Using white light ruins night vision for many minutes. Use red light only.

Tips for Better Sessions

• Let the optical tube reach outdoor temperature for 20 to 30 minutes before critical viewing. Warm air rising from the tube can cause shimmer.
• Keep dew at bay with a dew shield or a simple heater if your area is humid.
• Make a short list of targets before you go out, so you spend time observing rather than searching.
• Keep a simple observing log with dates, targets, eyepieces and what you saw. It helps you track improvement.

Recommended gear

A red-light headlamp helps you read the hand controller and charts without ruining your night vision, and it is one of the cheapest upgrades for any observer. View on Amazon

A dew shield reduces condensation on the objective lens during humid nights, keeping views clear for longer. View on Amazon

A 2x Barlow lens doubles the magnification of each eyepiece you own, giving you more options without buying several new eyepieces. View on Amazon

A lens cleaning kit with a blower and microfiber cloth keeps the objective and eyepieces free of dust and smudges. View on Amazon

FAQ

Can the National Geographic 70 show planetary detail?

Yes, it can show Jupiter’s cloud bands, the Galilean moons and Saturn’s rings. Detail depends heavily on atmospheric steadiness, so calm nights give the best results.

Do I need to align the mount every time I observe?

Usually yes, because the mount does not retain alignment reliably once it is powered off or moved. Some users find alignment quick enough that it is no burden at all.

What is the best first target for beginners?

The Moon is the most rewarding first target. It is bright, easy to locate and shows strong detail even through a small telescope.

Why does the goto keep missing objects?

Common causes include incorrect time or location, a poor alignment star choice, or an unlevel tripod. Recheck the settings and realign with well-separated bright stars.

Can I use it for astrophotography?

Basic lunar and planetary photos are possible with a smartphone adapter or a dedicated camera, but a 70mm refractor is limited for deep-sky imaging without a sturdy equatorial mount and tracking.

Do I need special filters?

A Moon filter reduces glare when the Moon is bright, and a color filter can add contrast on planets. Neither is essential for a first session.

Is it safe to look at the Sun with this telescope?

No. Never point any telescope at the Sun without a proper full-aperture solar filter fitted over the front of the objective. Eyepiece-mounted solar filters are dangerous and should not be used. If you are unsure about solar viewing, consult an experienced astronomy club member or a professional observatory for guidance.

Conclusion

The National Geographic 70 computerized refractor telescope rewards careful setup more than raw power. Level the tripod, enter your location and time accurately, and align on well-separated stars. Start with the Moon and bright planets, then move to larger deep-sky targets as your eyes adapt. With a little practice, the goto system becomes a helpful tool rather than a frustration.

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