National Geographic 70mm Refractor Telescope: Setup, Use and Buying Tips (2026)

Updated November 2026

A National Geographic 70mm refractor telescope is a small, lightweight scope that can show you the Moon’s craters, Jupiter’s four largest moons, Saturn’s rings and a good handful of bright star clusters. In this guide you will learn how to assemble the scope, align the finder, pick your first targets and get sharp views on your first night out. You will also get a short checklist for judging whether a national geographic 70mm refractor telescope fits your family’s needs.

What a 70mm Refractor Can and Cannot Show

A 70mm refractor uses a glass objective lens 70 millimeters across to gather light. Light-gathering power scales with the area of the lens, so a 70mm objective collects roughly four times the light of a 35mm lens. That is enough to show bright targets clearly, though faint galaxies and nebulae will look like soft gray smudges rather than the colorful photos you see in books.

Shopping for one? See our guide: 3 Best Orion Goscope III 70mm Refractor Travel Telescope Picks for Families.

Here is a realistic expectation list for families:

• Moon: Excellent. Craters, maria and the terminator (the line between light and shadow) are all easy to see.
• Jupiter: Good. You can usually see the cloud bands and the four Galilean moons as small points of light.
• Saturn: Good, when the planet is well placed. The rings are visible as a distinct oval, though the Cassini Division is hard to spot at low magnification.
• Venus: Shows phases, similar to the Moon.
• Open star clusters: The Pleiades and the Double Cluster in Perseus look especially nice at low power.
• Galaxies and nebulae: Faint and best from a dark site. The Orion Nebula is a rewarding target even from a suburban yard.

Refractors like this one generally have less color fringing than cheap achromatic scopes of the same size when they use better glass, but low-cost optics can still show some purple or blue halo around very bright objects. This is normal for a scope of this class and does not mean the telescope is broken.

Step-by-Step: Setting Up Your Telescope

Step 1: Attach the Tripod

Extend the tripod legs to a comfortable height for the person who will look through the eyepiece most often. Tighten the leg locks evenly. Many families find it easiest to set the tripod at about waist height for adults and to add a small step stool for kids. Spread the legs wide enough that the tripod feels stable when you lightly press on the mount.

Step 2: Mount the Optical Tube

Most entry-level refractors use an alt-azimuth mount, which moves up-and-down and side-to-side. Attach the tube to the mount using the dovetail or mounting bracket, then tighten the clamps firmly. Check that the tube swings freely without wobbling.

Step 3: Insert the Eyepiece

Loosen the focuser thumbscrew, slide in the lowest-power eyepiece (the one with the largest focal length number), and tighten the screw. Always start with low power. It gives a wide field, makes the image brighter and makes it much easier to find objects.

Step 4: Align the Finder Scope

The small finder scope mounted on the main tube is your best friend for aiming. Pick a distant daytime object, such as a utility pole or a treetop, and center it in the main eyepiece. Then adjust the finder’s alignment screws until the same object sits in the crosshairs of the finder. Do this in daylight. Once aligned, the finder should stay accurate unless someone bumps the tube hard.

Step 5: Focus on a Target

Begin with the Moon, since it is bright and easy to find. Use the finder to aim, then look through the eyepiece and slowly turn the focus knob until the edges look sharp. If you overshoot, reverse the direction. Refocusing is normal each time you change eyepieces.

A Simple First-Night Checklist

Before heading outside, gather these items so the session runs smoothly:

1. Telescope, tripod and all mounting hardware
2. All included eyepieces and any diagonal or barlow lens
3. A red-light flashlight, which preserves your night vision better than white light
4. A printed star map or a free planetarium app with night mode
5. A warm layer, a folding chair and a small snack for the observers
6. A lens cloth for dew on the front element

Choosing Your First Targets

A good beginner session follows a simple order. Start with the Moon at low power, then move to a bright planet, then finish with a star cluster. This gives everyone a quick win before the faint objects demand more patience.

Target	Best Time to Look	What to Look For	Suggested Eyepiece Power
Moon	Any clear night, especially near the quarter phases	Craters along the terminator	Low to medium
Jupiter	When visible in the evening sky	Cloud bands and four moons	Medium
Saturn	When visible in the evening sky	Ring shape and planet’s disk	Medium to high
Pleiades	Winter evenings in the Northern Hemisphere	Dozens of blue-white stars	Low
Orion Nebula	Winter evenings	Hazy patch around the middle star of Orion’s sword	Low to medium

Check a current sky chart before each session, since planet positions shift from month to month. The 70mm Refractor Telescope for Beginners: What to Know Before You Buy article covers how to match targets to seasons in more detail.

Understanding Magnification and Eyepieces

Magnification equals the telescope’s focal length divided by the eyepiece’s focal length. A typical 70mm refractor has a focal length near 700mm, so a 20mm eyepiece gives about 35x and a 10mm eyepiece gives about 70x. Higher power is not always better. Turbulence in the air, called seeing, often limits useful magnification to about 50x on an average night for a scope this size. Start low, then increase power only if the image stays steady and sharp.

If you want to learn more about how the optical parts interact, the Parts of Refractor Telescope: 5 Best Accessories Compared (2026) guide describes the components in plain language.

Recommended gear

A few accessories make the telescope easier to use and more comfortable for families. Consider these categories:

• Red-light flashlight: Keeps everyone’s night vision intact while you read charts or adjust settings. View on Amazon
• Planisphere: A rotating star wheel that shows the sky for any date and time, useful for kids learning constellations. View on Amazon
• Smartphone adapter: Lets you photograph the Moon or share views with a group on a phone screen. View on Amazon
• Sturdy observing chair: Reduces neck strain on long sessions, especially when looking at high objects. View on Amazon

Common Mistakes

• Starting with high power. Images look dim and shaky. Begin with the lowest-power eyepiece and work upward.
• Skipping daytime finder alignment. Aiming at night in the dark is frustrating and slows everyone down.
• Observing from inside a lit house. Light from windows and porch lamps reduces contrast. Step outside and let your eyes adjust for about 15 to 20 minutes.
• Touching the optics. Fingerprints and dust reduce sharpness. Use a soft brush or blower and gentle lens cleaning only when needed.
• Expecting photo-quality color. Most views are black, white and gray. Color appears mainly on bright planets and some double stars.
• Setting up on soft ground. A tripod sinking into grass will drift during the session. Use a flat patio or wooden deck when possible.

Tips for Families

• Let kids take turns finding the target with the finder scope. It builds real skill.
• Keep a simple observing log with the date, target and what everyone noticed. Kids enjoy drawing what they see.
• Plan sessions around the Moon phase. A bright full Moon washes out faint objects, while a new Moon is ideal for deep-sky targets.
• Pair your session with a short talk about the Moon’s surface or Jupiter’s moons. Simple facts stick with children.
• Keep sessions short. Thirty to forty-five minutes often works better for young observers than a marathon night.

FAQ

Is a National Geographic 70mm refractor telescope good for kids?

It can be a good first telescope for children, especially for Moon and planet viewing. Its light weight makes it easy for younger observers to move, and the simple setup suits a family who wants to learn together. Adult help with alignment and focusing is still useful at first.

What can I see with a 70mm refractor?

You can see lunar craters, Jupiter’s cloud bands and its four largest moons, Saturn’s rings, phases of Venus, and bright open star clusters such as the Pleiades. Faint galaxies and nebulae are harder and usually look gray rather than colorful.

Do I need a special mount or tripod upgrade?

Most families are happy with the included mount for casual viewing. A heavier, more stable tripod can reduce vibration when focusing or when kids touch the tube, so an upgrade is worth considering if the wobble bothers you.

What eyepiece should I start with?

Begin with the lowest-power eyepiece included with the telescope. It gives the widest field of view and the brightest image, which makes finding targets easier.

Why does the image look blurry?

The most common causes are incorrect focus, high magnification on a turbulent night, or a warm telescope in cool air that causes air currents inside the tube. Refocus slowly, try a lower power, and allow the scope to cool outdoors for about 20 to 30 minutes before observing.

Can I use the telescope from a city?

Yes. The Moon, planets and bright clusters are all visible from light-polluted areas. Faint deep-sky objects are much harder, so a darker site will help for those targets.

How do I clean the lens safely?

Start by blowing off loose dust with a rubber bulb blower. Use a soft brush for stubborn particles, then a lens-safe cleaning solution on a microfiber cloth if needed. Follow the manufacturer’s instructions, and consult a professional repair service if the optics are damaged.

Is a 70mm refractor better than a reflector for beginners?

Refractors are sealed, low-maintenance and fast to set up, which suits many families. Reflectors offer more light for the same price and size. Both can work well. The Reflector or Refractor Telescope for Beginner: Which Should You Choose? article compares the two in more depth.

Conclusion

A national geographic 70mm refractor telescope can deliver rewarding views of the Moon, planets and bright star clusters when you set it up carefully and start with low power. Align the finder in daylight, use a checklist for each session and keep your expectations realistic about color and faint objects. With a few steady nights of practice, your family can build a lasting habit of backyard stargazing.

Related reading

• Vivitar 60x/120x Refractor Telescope Review: Is It Worth It?
• Telescope Reflector or Refractor: How to Choose the Right One for Your Family
• How Do You Explore Scientific Refractor Telescope Skies? A Beginner's Guide

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