Does the Celestron binoviewer come with eyepieces?

No. It needs a matched pair of 1.25 inch eyepieces, sold separately; the In use photographs show mine with two Celestron 40 mm Plossls.

Will it reach focus on my telescope?

Celestron says it uses about 3.5 inches of back focus and suits catadioptric telescopes and other designs with enough back focus, so check your telescope's before you buy.

Can you put two zoom eyepieces in it?

You can. With two in mine the view of the Orion Nebula was immersive, but I could not get two perfectly aligned images, likely because the two zooms were not at exactly the same magnification.

Where can I buy the Celestron binoviewer?

The prices I recorded: £242 at Widescreen Centre (UK), listed; $260 at Agena Astro (US), in stock; $92 at AliExpress (Global), listed.

What have I not tested on the binoviewer?

I have not measured how much light reaches each eye or tried it on a Schmidt-Cassegrain.

Celestron Stereo Binocular Viewer review: both eyes on the sky

Where does it rank on our leaderboard

Nine of the 46 accessories on my board, against price
Rank	Accessory	Stars for Your Buck	Recorded UK price
1	GEMINI EAF	100 out of 100	£42
2	Generic Dew Heater	93 out of 100	£9
9	SVBONY Dew Heater	85 out of 100	£19
13	ASIAIR Plus 256GB	81 out of 100	£399
32	ZWO PE200	53 out of 100	£219
36	Celestron 2x Barlow	46 out of 100	£135
42	Celestron Binoviewers	40 out of 100	£242
45	SKY ROVER 2x54 Binoculars	28 out of 100	£139
46	365 Solar Telescope Cover	5 out of 100	£73

Contents

01 Where does it rank on our leaderboard
02 Specifications and features
03 In use
04 In my words
05 Watch it in my videos
06 Should you buy it?
07 Questions and more about this review

In 30 seconds

Stars for Your Buck 40/100

Reviewed 13 Dec 2023 Updated 25 Sep 2026

Rank: #42 of 46 accessories
Verdict: With reservations

Written by Damon Scotting 3 min read

Buy it if

You observe visually and want to use both eyes
You have, or will buy, a matched pair of 1.25 inch eyepieces
Your telescope has about 3.5 inches of back focus to spare

Skip it if

You want the brightest possible view of faint galaxies and nebulae
You want to use it with two zoom eyepieces: both must sit at exactly the same magnification to give one clean, aligned image
You image with a camera rather than observe

“The view you do get though is extremely immersive; it's such a relief not having to squint your non-viewing eye whenever looking through a telescope.”

Specifications and features

Celestron Binoviewers reviewed #42 of 46
Recorded UK price	£242
Model	Celestron 93691
Barrel and holders	1.25 inch
Clear aperture	22 mm
Prisms	BaK-4
Coatings	Fully multi-coated
Interpupillary distance	54 to 75 mm
Back focus used	About 3.5 inches
Focus	Each eyepiece holder, with marked diopter settings
Filter threads	Yes, on the 1.25 inch barrel
Eyepieces	Not included (a matched pair needed)
Weight	510 g
Case	Aluminium, foam-lined

In use

Both eyes lit by the view

On the ZWO FF110

With two Celestron 40 mm Plossls

The twin eyepieces

The whole rig with the binoviewer

At the eyepieces

In my words

“Perhaps the first thing to note when using binoviewers is that you are merely looking at the same view twice, with the light from the telescope being split between two avenues.”

From my 9 coolest accessories video

“One difficulty that I did suffer from unfortunately was I couldn't get two perfectly aligned clean images. This is likely due to the zoom eyepieces not being of the exact same magnification.”

From my 9 coolest accessories video

“In a video that I made a while back, I suggested combining two zoom eyepieces with a binoviewer to use with a telescope. I've never seen anyone attempt this before or since the video, but I was actually very surprised to find that it worked really well. Observing the Orion Nebula was a fairly surreal experience, it really gave the deep sky object a sense of depth.”

From one of my videos

Watch it in my videos

The 9 COOLEST Accessories for ASTRONOMY! · published 13 December 2023 · 17:00 · Watch on YouTube · 19,597 views, 974 likes on 2 Oct 2026

Jump to

3:06 Two zoom eyepieces in a binoviewer
3:40 The view through the binoviewer

Should you buy it?

40/100 Stars for Your Buck

Pros

Both eyes at the eyepiece, with no squinting of the other eye.
22 mm BaK-4 prisms, fully multi-coated, and each eyepiece holder focuses on its own, with marked diopter settings.
It takes any matched pair of 1.25 inch eyepieces, from Plossls to zooms.
Interpupillary distance from 54 to 75 mm, and a foam-lined aluminium case comes with it.

Cons

The light is split between two eyepieces, so each eye gets a dimmer view than one eyepiece would give.
No eyepieces in the box: you need a matched pair of 1.25 inch eyepieces.
It uses about 3.5 inches of back focus; Celestron pitches it at catadioptric telescopes and other designs with enough to spare.

Zoom eyepieces plus binoviewers is a cool concept but not actually very practical.

Three alternatives I have reviewed

Questions and more about this review

Reviewed by

Damon Scotting

The Telescope Man Verified

BSc (Hons) Physics with Astrophysics and Cosmology, Loughborough University PGCE / QTS, University of Nottingham

About Damon About Damon Damon Scotting is The Telescope Man. He holds a BSc (Hons) in Physics with Astrophysics and Cosmology from Loughborough University and a PGCE with QTS from the University of Nottingham, and taught physics in secondary schools before becoming an astronomy creator. He is a contributing writer for BBC Sky at Night Magazine and the author of 42 Wonders of Our Night Sky, and his photograph of the galaxy M100 with the dwarf planet Ceres was Highly Commended in the Astronomy Photographer of the Year 2024 competition run by Royal Observatory Greenwich. He has appeared on the BBC's Blue Peter. More than 750,000 people follow his astronomy channels on YouTube, Instagram and TikTok, and he has reviewed more than 140 telescopes, mounts, cameras, filters and accessories hands-on for this site. More about Damon · How I test · Damon's book

I review all kinds of gear: most of it I buy, some is gifted and some is loaned, and all of it is reviewed the same way. How this site is funded

Five questions, answered

Questions about the Celestron Binoviewers

Reviewed 13 December 2023 ·Updated 25 September 2026

I review all kinds of gear. Most of it I buy, some is gifted and some is loaned, and all of it is reviewed the same way: no company sees or approves a review before it is published. Shop links marked Ad are affiliate links: I earn a commission when you buy through them, at no extra cost to you. How this site is funded

Does the Celestron binoviewer come with eyepieces? No. It needs a matched pair of 1.25 inch eyepieces, sold separately; the In use photographs show mine with two Celestron 40 mm Plossls. In use ↓
Will it reach focus on my telescope? Celestron says it uses about 3.5 inches of back focus and suits catadioptric telescopes and other designs with enough back focus, so check your telescope's before you buy. The specifications ↓
Can you put two zoom eyepieces in it? You can. With two in mine the view of the Orion Nebula was immersive, but I could not get two perfectly aligned images, likely because the two zooms were not at exactly the same magnification. In my words ↓
Where can I buy the Celestron binoviewer? The prices I recorded: £242 at Widescreen Centre (UK), listed; $260 at Agena Astro (US), in stock; $92 at AliExpress (Global), listed. A record, not a live price The verdict, the readers and the sellers ↓
What have I not tested on the binoviewer? I have not measured how much light reaches each eye or tried it on a Schmidt-Cassegrain.