50x / 100x Refractor Telescope: What You Can Really See

Updated November 2026

A 50x / 100x refractor telescope can show you the Moon’s craters, Saturn’s rings, Jupiter’s cloud bands and the brighter star clusters in clear skies. These magnifications are useful, but they are only part of the story. The aperture, the eyepiece quality and the steadiness of your mount decide whether those powers look sharp or just big and blurry.

What 50x and 100x Actually Mean

Magnification is the focal length of the telescope divided by the focal length of the eyepiece. A 50x setting on a 700mm focal length scope uses a 14mm eyepiece, while 100x uses a 7mm eyepiece. Magnification alone does not tell you much about image quality, so check the aperture as well.

Shopping for one? See our guide: 4 Best Vivitar 50x 100x Refractor Telescopes with Tripod Picks for Beginners.

Most manufacturers list a maximum useful magnification of roughly 50 times the aperture in inches, or about 2 times the aperture in millimeters. A small refractor with a 60mm objective will show crisp detail at 50x but often struggles to hold a clear image at 100x. Treat advertised powers above that limit with caution.

Step 1: Match the Eyepiece to the Target

Start at 50x for most objects. It gives a wide enough field to find targets and keeps the image bright. Step up to 100x only when the seeing is steady and the object is small and bright enough to hold detail.

• Use a 20mm or 25mm eyepiece to find and frame targets.
• Use a 10mm to 14mm eyepiece for general views at around 50x.
• Use a 6mm to 7mm eyepiece only for the Moon, Jupiter or Saturn on steady nights.

Step 2: Set Up a Stable Mount and Tripod

Vibration ruins high-power views faster than anything else. Extend the tripod legs only as far as you need, and place them on firm ground rather than grass or a soft deck. Let the tube cool for 20 to 30 minutes after moving it outside, because thermal currents inside a warm tube blur the image.

Step 3: Judge Sky Conditions Before You Raise the Power

Atmospheric steadiness, called seeing, changes from night to night and even minute to minute. On a night when stars twinkle hard, stay near 50x. On a night when stars look like steady points, try 100x on the Moon first, since it is bright and easy to focus on.

Target	Good starting power	Power to try on steady nights
Moon	50x	100x
Jupiter	50x	100x
Saturn	50x	100x
Star clusters	50x	Usually not needed

Recommended gear

A decent set of eyepieces matters more than the telescope body for high-power views, since cheap eyepieces often add color fringing and soft edges. A sturdy tripod also keeps 100x views usable.

• Plossl eyepieces in 6mm, 10mm and 25mm give a good spread of powers and sharper edges than kit eyepieces. View on Amazon
• A solid aluminum tripod with a slow-motion alt-az head reduces vibration and makes fine tracking easier at high power. View on Amazon

Common Mistakes

• Chasing 100x on a small aperture scope, which produces dim, soft images.
• Observing before the tube reaches outdoor temperature, causing blurry views.
• Touching the tripod or tube during observing, which shakes the image.
• Judging the telescope on a single bad night with poor seeing.
• Buying low-power eyepieces only and expecting high-power planetary views.

For more on how the body and lens design affect these results, see Refractor Telescope Optical Glass and Metal Tube: What Each Build Shows You and Refractor Telescope 60x 120x: What Those Magnifications Really Mean.

FAQ

Can a refractor telescope really show detail at 100x?

Yes, on the Moon and bright planets, provided the aperture is large enough and the sky is steady. Smaller refractors often look better at 50x than at 100x.

Is 50x a good starting magnification?

For most beginners, 50x is a practical starting point. It is bright, easy to focus and forgiving of small vibrations.

Which targets work best at high power?

The Moon, Jupiter and Saturn respond best to higher magnification. Deep-sky objects usually look better at lower power because they need a wider field and more light.

Conclusion

A 50x / 100x refractor telescope is best used with 50x as your everyday power and 100x reserved for steady nights and bright targets. Match the eyepiece to the object, let the tube cool, and keep the mount stable. Those three habits will do more for your views than any single spec on the box.

Related reading

• Vivitar 50x 100x Refractor Telescope: What It Shows and How to Use It
• Terraen 50x 100x Refractor Telescope Price: What to Expect and How to Judge It
• Brookstone 50x 100x Refractor Telescope: What It Shows and How to Use It

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