Best Telescope Zoom Eyepieces in 2026: 8 Zooms Compared

The best telescope zoom eyepiece for most people is the Celestron 8-24mm. It costs under $125, fits any 1.25-inch focuser and covers every focal length from 8 to 24 mm. For the best optics, buy the Baader Hyperion Mark IV. For the widest view, buy the SVBONY SV230. For planets, buy the SVBONY SV215 or the Tele Vue 3-6mm Nagler Zoom. For the lowest price, buy the SVBONY SV135 7-21mm.

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Orion closed in July 2024, so its 8-24mm Pro Lanthanum zoom is no longer on this list.

The right zoom depends on your telescope. Enter its aperture and focal length in the finder below to see the power range, true field and exit pupil of every zoom in your telescope. The finder flags any zoom that goes past the useful limit of your aperture and ranks the three that fit best.

What a zoom eyepiece is

A zoom eyepiece is an eyepiece with a variable focal length. You turn a ring to change the focal length while the eyepiece stays in the focuser or diagonal, so the magnification changes without swapping eyepieces. Most zooms cover 7 to 21 mm or 8 to 24 mm. A few cover a shorter range for planets, such as 3 to 6 mm or 3 to 8 mm.

Magnification is the telescope focal length divided by the eyepiece focal length. An 8-24mm zoom in a telescope with a 1200 mm focal length gives 150x at 8 mm and 50x at 24 mm, and every power in between. Five fixed eyepieces would be needed to cover the same range in steps of 4 mm.

Zoom eyepiece tradeoffs

A zoom gives up some optical performance for range. Six tradeoffs matter when you choose one.

Narrower apparent field. Apparent field is how wide the view looks to your eye. A fixed wide-angle eyepiece holds 68° or more at every focal length. Most zooms do not. The Celestron 8-24mm gives 60° at 8 mm and narrows to 40° at 24 mm. The SVBONY SV135 goes from 57° to 40°, the Baader Mark IV from 68° to 48° and the SVBONY SV230 from 72° to 57°. Three zooms hold one field at every setting: the SVBONY SV215 at 56°, the SVBONY SV245 at 63° and the Tele Vue at 50°. The narrow end of a variable zoom is the low-power end, which is where a wide view matters most for star clusters and large nebulae.

More glass. A Plossl has four lens elements. The zooms in this guide have five to nine: 5 in the Tele Vue, 6 in the Celestron and SV135, 7 in the Baader and SV191, 8 in the SV245 and 9 in the SV230. Every extra surface scatters a little light and gives off-axis aberrations another place to appear, so a zoom is rarely as sharp at the edge or as high in contrast as a good fixed eyepiece of the same focal length. All eight zooms here are fully multi-coated, which limits the light lost to reflections.

Focus. A parfocal zoom stays in focus as the focal length changes. The Baader, SV230, SV245, SV215 and Tele Vue are parfocal. SVBONY notes that the SV215 may need a minor adjustment. The Celestron 8-24mm and the SVBONY SV191 are not parfocal, so you refocus after every change.

Eye relief that moves. Eye relief is the distance from the lens at which your eye sees the full field. In a zoom it changes with the focal length. The Baader gives 19 mm at 8 mm and 16 mm at 24 mm. The SV135 gives 18 mm and 16.3 mm. The Tele Vue holds 10 mm, which is too short for most eyeglass wearers.

Fast telescopes. Zoom designs work best with the slower light cone of an f/7 or longer telescope. In telescopes faster than about f/6 the edges soften and bright stars show color fringing. The finder prints a note when your telescope is faster than f/6.

Weight. The SV230 and SV245 weigh about 500 g, more than twice the Celestron at 225 g and more than three times the Tele Vue at 136 g. A heavy eyepiece can unbalance a small telescope. The zoom ring also stiffens in cold weather.

Are zoom eyepieces worth it?

A zoom is worth buying when you want many magnifications for little money. It costs more than one fixed eyepiece of the same quality and less than the four or five fixed eyepieces you need to cover the same range. A good Barlow plus two good eyepieces costs more than a single zoom.

A zoom suits a first telescope, because the eyepieces that come with it give two or three powers and a zoom fills the gaps. It suits observers who want to learn which power shows a target best by turning a ring instead of swapping eyepieces. It suits travel, because one zoom replaces a case of eyepieces.

When not to buy a zoom eyepiece

• You need a very short or very long focal length. Most zooms stop at 7 or 8 mm on the short end and 21 or 24 mm on the long end. Below 7 mm or above 24 mm, buy a fixed eyepiece or a planetary zoom such as the SV215.
• You want the widest field. A fixed 68° or 82° eyepiece shows more sky at the same power than any zoom here.
• Your telescope is faster than f/6 and edge sharpness matters. A fixed Plossl or wide-angle eyepiece holds up better.
• The zoom range does not match what your telescope can show. A 70 mm refractor with a 700 mm focal length tops out near 140x. An 8-24mm zoom there runs from 29x to 88x and leaves 88x to 140x uncovered, so planets call for a 5 mm eyepiece or a 7-21mm zoom, which reaches 100x.

How to choose a zoom eyepiece

Match the zoom range to your telescope

Three formulas describe what a zoom does in your telescope. The finder above runs all three for every zoom at both ends of its range.

• Power = telescope focal length / zoom focal length. The shortest setting gives the highest power.
• True field = apparent field / power. This is how much sky you see, in degrees. The Moon is about half a degree across.
• Exit pupil = aperture / power. Around 2 to 4 mm suits deep-sky objects and 0.5 to 1 mm suits planets. Above 7 mm, light falls outside your eye.

The highest useful power is 2x the aperture in millimeters, which is an exit pupil of 0.5 mm. An 80 mm refractor stops near 160x and an 8-inch (203 mm) telescope near 400x. Power past that limit makes the image bigger and dimmer without showing more detail. The finder flags a zoom whose top power passes the limit and tells you the focal length below which to stop.

• 80 mm refractor, 900 mm focal length, limit 160x: the Celestron 8-24mm gives 38x to 112x. The SVBONY SV215 3-8mm gives 112x to 300x, of which 112x to 160x is useful.
• 8-inch Dobsonian, 1200 mm focal length, limit 406x: the Celestron 8-24mm gives 50x to 150x. The SV215 gives 150x to 400x, all of it useful.

The 8-24mm zoom suits both telescopes for low and medium power. The 3-8mm zoom is a planetary eyepiece for the Dobsonian. In the refractor only its 8 to 5.6 mm end is useful, because 3 mm would give 300x. For power numbers on your own telescope, use the eyepiece magnification chart or the finder.

Barrel size

Most beginner telescopes take 1.25-inch eyepieces. The SVBONY SV230, SVBONY SV245 and Baader Mark IV also come with a 2-inch barrel for 2-inch focusers. A 1.25-inch zoom fits a 2-inch focuser through the adapter that comes with the focuser. Check the barrel size printed on the focuser or in the telescope specifications.

Click stops and parfocal design

Click stops are detents at set focal lengths. They let you change power in the dark without looking at the ring. The Baader has them at 8, 12, 16, 20 and 24 mm. The Tele Vue has them at 3, 4, 5 and 6 mm. The SV215 has them at every millimeter from 3 to 8. Parfocal design saves a refocus after each change, which matters most at high power where the focus range is narrow.

Eye relief and apparent field

Eyeglass wearers want 15 mm of eye relief or more. The Baader, SV230, SV245, SV135 and SV191 give 16 to 20 mm. The SV215 and the Tele Vue give 10 mm. A wider apparent field shows more sky at the same power. The Baader at 68° and the SV230 at 72° are the widest zooms here at their short ends.

Zoom eyepiece or Barlow lens

A zoom eyepiece and a Barlow lens both give you more magnifications, but they do different jobs. A Barlow multiplies the power of every eyepiece by 2x or 3x. A zoom replaces several eyepieces with one. If you own two or three eyepieces already, a Barlow adds the most for the least money. If you own one or two, a zoom adds more focal lengths.

You can use both. A 2x Barlow turns an 8-24mm zoom into a 4-12mm zoom with twice the power at every setting. Baader sells a 2.25x Barlow for the Hyperion that gives 3.6 to 10.7 mm. A Barlow also moves the focus position, so refocus after you add one. See the best Barlow lenses for the ones worth buying and how a Barlow lens works. For a longer comparison with fixed eyepieces, read zoom eyepieces vs fixed eyepieces.

The best zoom eyepieces reviewed

Best overall value: Celestron 8-24mm Zoom

The Celestron 8-24mm is the zoom to buy first. It has six elements in four groups, fully multi-coated optics, a fold-down eye guard and filter threads. It weighs 225 g. The field runs from 60° at 8 mm to 40° at 24 mm. Celestron lists it as not parfocal, so you touch the focus after each change. In telescopes faster than f/6 the edges show some aberration. Celestron’s specification page gives 6 mm of eye relief while dealers list 15 to 18 mm, so try it with your glasses before you count on it.

Best overall value

Best for: A first zoom for any 1.25" telescope

Zoom range

8-24 mm

Apparent field

60° at 8 mm, 40° at 24 mm

Eye relief

Not listed

Barrel

1.25"

Parfocal

No

Click stops

Not listed

Weight

225 g

Optics

6 elements in 4 groups

Pros

• Covers every focal length from 8 to 24 mm
• Fits any 1.25" focuser and takes 1.25" filters
• Brand support and a 2-year US warranty

Cons

• Not parfocal: refocus after each change
• Field narrows to 40° at 24 mm
• Edges soften in telescopes faster than f/6

Celestron's page lists eye relief as 6 mm while dealers and Celestron's earlier listing give 15 to 18 mm, so it is left blank here. Celestron publishes the field as 40 to 60 degrees; a Telescopic Watch review puts 60 degrees at 8 mm and 40 degrees at 24 mm.

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Best premium zoom: Baader Hyperion Mark IV 8-24mm

The Baader Hyperion Mark IV is the best zoom for optics and the one to buy for a binoviewer. It has seven elements in four groups, is parfocal and clicks at 8, 12, 16, 20 and 24 mm. The field runs from 68° at 8 mm to 48° at 24 mm and eye relief from 19 mm to 16 mm. It weighs 290 g with the 1.25-inch barrel and 309 g with the 2-inch barrel, and both barrels come in the box. It is the only zoom here designed for two-eyed viewing. It costs about three times the Celestron.

Best premium zoom

Best for: Sharpest optics and binoviewers

Zoom range

8-24 mm

Apparent field

68° at 8 mm, 48° at 24 mm

Eye relief

16-19 mm

Barrel

1.25" and 2"

Parfocal

Yes

Click stops

8, 12, 16, 20, 24 mm

Weight

290 g

Optics

7 elements in 4 groups

Pros

• 68° field at 8 mm, the widest of the 8-24 mm zooms
• Parfocal, with click stops at five focal lengths
• 16 to 19 mm eye relief and both 1.25" and 2" barrels

Cons

• Costs about three times the Celestron
• Field narrows to 48° at 24 mm
• Heavier than the Celestron at 290 g

Field, eye relief and weight come from the Baader Mark IV manual: 68, 63, 58, 53 and 48 degrees at 8, 12, 16, 20 and 24 mm, eye relief 19 to 16 mm, 290 g with the 1.25" barrel and 309 g with the 2" barrel. One dealer lists 12 to 15 mm of eye relief.

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Best wide-field zoom: SVBONY SV230 8-20mm

The SVBONY SV230 has the widest field of any zoom here: 72° at 8 mm and 57° at 20 mm. It has nine elements in six groups with aspheric lenses, 17 to 19 mm of eye relief and a parfocal design with click stops. Both 1.25-inch and 2-inch barrels fit without an adapter. At 500 g it is the heaviest zoom in this guide and can unbalance a small telescope. The 20 mm limit means it does not reach the lowest powers of a 24 mm zoom.

Best wide-field zoom

Best for: The widest view of any zoom

Zoom range

8-20 mm

Apparent field

72° at 8 mm, 57° at 20 mm

Eye relief

17-19 mm

Barrel

1.25" and 2"

Parfocal

Yes

Click stops

Yes

Weight

500 g

Optics

9 elements in 6 groups

Pros

• 72° field at 8 mm, the widest of any zoom here
• 17 to 19 mm eye relief
• Parfocal, with click stops and both barrels in the box

Cons

• 500 g is the heaviest zoom in this guide
• Longest focal length is 20 mm
• Costs several times the SV135

Svbony's product page lists click stops at each mm from 8 to 19 plus 24 mm, so the positions are not repeated here.

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Best mid-price zoom: SVBONY SV245 8-16mm

The SVBONY SV245 doubles the power across its range, from 8 to 16 mm, with a constant 63° field and 17 to 18 mm of eye relief. It has eight elements in five groups, a parfocal design and detents at every millimeter. It takes 1.25-inch and 2-inch barrels and weighs 486 g. It has no low-power end, so pair it with a 25 mm or longer eyepiece for finding targets. It costs less than the SV230.

Best mid-price zoom

Best for: A parfocal 2x zoom at a middle price

Zoom range

8-16 mm

Apparent field

63°

Eye relief

17-18 mm

Barrel

1.25" and 2"

Parfocal

Yes

Click stops

Every mm from 8 to 16

Weight

486 g

Optics

8 elements in 5 groups

Pros

• 63° field at every setting
• 17 to 18 mm eye relief
• Parfocal, with a detent at every millimeter

Cons

• No low-power end: 16 mm is the longest
• 486 g can unbalance a small telescope
• Narrower focal range than an 8-24 mm zoom

Eye relief is 18 to 17 mm on the svbony.com comparison table and 17 to 18 mm on the Amazon listing. The listing says the zoom takes 1.25" and 2" barrels.

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Best budget zoom: SVBONY SV135 7-21mm

The SVBONY SV135 is the lowest-priced zoom in the guide. The field runs from 57° at 7 mm to 40° at 21 mm. Eye relief is 18 mm at the short end and 16.3 mm at the long end. It has six elements in four groups, a rubber eye guard and a 133 g body. SVBONY sells it under several listings that quote different fields (36 to 52°, 40 to 57° and 40 to 60°). The listing linked here is the 40 to 57° version.

Best budget zoom

Best for: The lowest price for a 7-21 mm zoom

Zoom range

7-21 mm

Apparent field

57° at 7 mm, 40° at 21 mm

Eye relief

16.3-18 mm

Barrel

1.25"

Parfocal

Not stated

Click stops

Not listed

Weight

133 g

Optics

6 elements in 4 groups

Pros

• Lowest price of the eight zooms
• Goes down to 7 mm
• 18 to 16.3 mm eye relief

Cons

• Parfocal design not stated
• Field narrows to 40° at 21 mm
• Listings disagree on the field figure

svbony.com gives 57 to 40 degrees and the Amazon title gives 40 to 57 degrees. Other SV135 listings give 36 to 52 and 40 to 60 degrees. This listing is the 40 to 57 degree version.

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Best planetary zoom: SVBONY SV215 3-8mm

The SVBONY SV215 covers 3 to 8 mm with click stops at every millimeter. The apparent field stays at 56° and eye relief at 10 mm across the range. It has six elements in four groups and is parfocal. It needs focal length to work: in an 8-inch Dobsonian with a 1200 mm focal length it gives 150x to 400x, and in an 80 mm refractor with a 900 mm focal length it passes the 160x limit at 5.6 mm. It is a planet and Moon eyepiece with no low power at all.

Best planetary zoom

Best for: Planets and the Moon at 150x and up

Zoom range

3-8 mm

Apparent field

56°

Eye relief

10 mm

Barrel

1.25"

Parfocal

Yes

Click stops

3, 4, 5, 6, 7, 8 mm

Weight

Not listed

Optics

6 elements in 4 groups

Pros

• Constant 56° field
• Click stops at 3, 4, 5, 6, 7 and 8 mm
• Replaces several high-power eyepieces

Cons

• 10 mm eye relief is short for glasses
• No low power: it only suits planets and the Moon
• Passes 2x aperture in small telescopes

Weight is not listed on svbony.com or Amazon. Svbony says the zoom is parfocal with minor tweaking at times.

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Best high-power zoom: Tele Vue 3-6mm Nagler Zoom

The Tele Vue 3-6mm Nagler Zoom is the premium planetary zoom. It holds a 50° field across the range, is parfocal and clicks at 3, 4, 5 and 6 mm. It has five elements in three groups, weighs 136 g and takes a 1.25-inch barrel. Eye relief is 10 mm, which is too short for most eyeglass wearers. It reaches 200x to 400x in an 8-inch Dobsonian with a 1200 mm focal length and is not useful in a small telescope. It costs more than any other zoom here.

Best high-power zoom

Best for: The best high-power zoom

Zoom range

3-6 mm

Apparent field

50°

Eye relief

10 mm

Barrel

1.25"

Parfocal

Yes

Click stops

3, 4, 5, 6 mm

Weight

136 g

Optics

5 elements in 3 groups

Pros

• Constant 50° field and constant 10 mm eye relief
• Parfocal, with click stops at each millimeter
• Weighs 136 g

Cons

• Costs more than any other zoom here
• 10 mm eye relief is short for glasses
• Only useful in telescopes with a long focal length

Weight is 0.3 lb on optcorp.com. Other dealers list 150 g and 200 g.

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Best budget wide-angle zoom: SVBONY SV191 7.2-21.6mm

The SVBONY SV191 gives 65° at 7.2 mm and 42° at 21.6 mm for less than the cost of the SV215. Eye relief is 18 to 20 mm, the longest in the guide, and the twist-up metal eyecups suit eyeglass wearers. It has seven elements in four groups and weighs 167 g. It is not parfocal, so you refocus after each change. The listing and the maker give the field as a range without saying which end is wider, so the guide uses the usual zoom pattern of the wide end at the short focal length.

Best budget wide-angle zoom

Best for: Long eye relief at a low price

Zoom range

7.2-21.6 mm

Apparent field

65° at 7.2 mm, 42° at 21.6 mm

Eye relief

18-20 mm

Barrel

1.25"

Parfocal

No

Click stops

Not listed

Weight

167 g

Optics

7 elements in 4 groups

Pros

• 18 to 20 mm eye relief, the longest here
• 65° field at the short end
• 167 g body

Cons

• Not parfocal: refocus after each change
• Field narrows to 42° at 21.6 mm
• Which end is wider is not stated by the maker

Svbony lists the field as 42 to 65 degrees without saying which end is wider; the guide assumes 65 degrees at 7.2 mm. Weight is 167 g on svbony.com and 0.32 kg on Amazon (shipping weight).

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Zoom eyepiece comparison

All eight zooms side by side. Apparent field is given at the short and long focal length of each zoom. Slide the table sideways on a phone.

Accessories for a zoom eyepiece

A Barlow doubles the range of a zoom. Filters and a case suit a zoom as they suit any eyepiece. For more eyepieces to go with a zoom, see the best telescope eyepiece sets and the best eyepieces for planets.

Zoom eyepiece FAQ