Explore Scientific 24mm 82° field argon-purged waterproof 2" eyepiece


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This 82° field Explore Scientific 24mm 2" argon-purged waterproof eyepiece makes observing feel like you're relaxing in front of a picture window on the Universe, rather than squinting through an eyepiece.
Our Product #: ES8224A
Explore Scientific Product #: EPWP8224-01

Product Description

This 2" 24mm Explore Scientific is an excellent low power eyepiece with a wide, wide fully-immersive 82° field of view that's particularly well-matched to big Dobsonian scopes and short focal ratio refractors. Viewing through this 24mm Explore Scientific makes you feel like you're floating above the Earth, taking a space walk, rather than looking through a telescope eyepiece. This is an eyepiece that shows you a truly relaxed and unconfined "picture window" view of space.

While the longer focal length 30mm Explore Scientific provides an even wider field of view with an f/4.5 scope, the 30mm also has a very large 6.7mm exit pupil that is larger than many observers' eyes can dilate. That effectively wastes some of a Dob's light gathering capacity, as some of the full light cone falls on the observer's iris, rather than entering his or her eye.

In addition to its wide field, the 24mm Explore Scientific has an extra benefit for you. It is O-ring sealed and argon-purged to be 100% waterproof. This prevents internal fogging in the eyepiece; keeps the interior dust-and fungus-free; and makes it easier to clean, as there is no risk of excess cleaning solution getting trapped between the lenses.

The latest computer design programs have been used to optimize its performance. Its six element/four group design uses low dispersion and high refractive index lenses and full multicoatings for high contrast, high resolution, and flat field images across its very wide 82° field of view. The lens edges have been blackened to improve contrast.

A 12" f/4.5 Dobsonian reflector will have a full 1.43° field at 57x with this eyepiece, able to encompass all of the Pleiades in one field. Even an 8" f/10 catadioptric will have a 0.98° field almost two lunar diameters across, for thrilling views of the larger nebulas, like Orion. You can use the calculator in the "formula" tab above to see just how wide the field will be with your particular telescope.

With 17mm of eye relief, this Explore Scientific eyepiece provides virtually unvignetted views for eyeglass wearers, although the 82° field of view is so wide that even non-eyeglass wearers can't see the whole field at once. All observers have to move their eye from side to side to take in the immense view, so vignetting in the conventional sense is not a problem.

The eyepiece has a soft fold-down rubber eyecup and comes with dust covers for both ends of the eyepiece.

This individually serial numbered Explore Scientific eyepiece is backed by a limited one year warranty, which will be extended to an Explore Scientific transferable lifetime limited warranty when its warranty card is registered with Explore Scientific within 60 days of purchase.  Here's a link to full details on this unique transferable lifetime warranty.

Tech Details

Barrel Size 2"
Eye Relief 17mm
Field of view 82
Focal Length 24mm
Number of optical elements 6
Weight 1.6 lbs.
Warranty 1 year, extendable to lifetime


Review by:
Love this for nebula, globs and clusters. Nice dark back ground with a lot of sky in in the view. One can spend some time just looking around at whit is in the view it gives. (Posted on 10/25/2019)
Review by:
This eyepiece is substantial. It is big. I’m not criticizing it, though. If you’ve never seen it in person, it is bigger than you think it will be. It’s heavy, too. It feels like it’s worth several hundred dollars. It is also one of the greatest eyepieces I’ve ever looked through. The first time I used it was when I borrowed it at a star party. Clear, wide views of the cosmos sold me on this eyepiece immediately and I bought one the next day. There’s great contrast and most of the field is aberration-free. I can’t imagine anyone being disappointed when looking through it. But, be aware that it is huge. I use it primarily on my 10” dob and I have to adjust the counterweights when I put this EP on or remove it. It is far larger than any other eyepiece I own. (Posted on 10/6/2019)
Review by:
The ES82 24mm is a great high performance midfield eyepiece that happens to come at a lower price than its capability might lead you to expect. I use this in my Celestron 8" and 11" CPC's and it gives me great views of galaxies, clusters and nebula's. The stars are pinpoint in focus all the way to the edge of the EP. Very pleased with the quality and finish of the ES EP's. I now own 4 2" ES EP's . Highly recommend this one for nice deep sky viewing. (Posted on 9/10/2019)
Review by:
I purchased the ES82 24mm 2" for both my Orion ST120 f/5 refractor , and my soon-to-be-aquired AT72EDII. FoV with the 24 on the 120 is 3.28*, and will be 4.58* on the AT72EDII.

The ES82 24mm 2" is a very good ocular, and does quite well in sharpness and contrast, color is good and edge of field performance is good with the fast refractor.

Eye relief is tight, but I do not wear spectacles while observing so the ER is good enough. Though, even jamming my eyeball into the eye lens of the 24, I still could not see the edge of the image circle; gotta move the head around for that.

I will not knock this ocular for it's weight, because it's a 2" ocular with a lot of glass in it to allow for it's quality 82* AFoV. It's size works well with what it offers, no-bones there.

This ocular is a keeper, and it will retire it's smaller brother, the ES68 24mm 1.25" from duty and to seek a new home.


The Other Jason (Posted on 8/26/2019)
Review by:
This is my widest field EP, so it gets a lot of use on open clusters and diffuse nebulae. It's a perfect match for an SCT with a 0.63x reducer. As noted by others, it's best without glasses but usable with them. (Posted on 7/22/2019)
Review by:
In many ways I like this eyepiece better than the now discontinued TV 26 mm Nagler which I also own. The 24 mm ES/82 costs less than half the price too. The eye relief is good for me as I observe with glasses off. Eye relief will be tight for those that observe with glasses on. No astigmatism noted and an almost completely flat field. Good alternative to the TV Type 4 Nagler 22 for those needed a more economical eyepiece. (Posted on 1/13/2019)
Review by:
This is my starting 'finder' eyepiece. With my 12.5" f4.8 dob I get a 1.3 degree FOV @64x. Excellent optics. Stars are point-like to the edge of the FOV.
(Posted on 1/4/2019)
Review by:
This is my starting 'finder' eyepiece. With my 12.5" f4.8 dob I get a 1.3 degree FOV. Excellent optics. (Posted on 1/4/2019)
Review by:
I use this eyepiece on my 10" f/4.7 (1200mm FL) Dobsonian for 50X magnification and a ~7mm exit pupil. It's definitely my favorite eyepiece out of this and some higher magnification Dual ED Paradigm eyepieces. Personally, although I'm only a beginner, I found the view to be incredibly sharp and free of aberrations all the way out to the edge of the FOV. And it's really quite an impressive FOV.

I did have a QC issue - an O-ring on the telescope side was bulging out, meaning it wouldn't be able to hold that Argon seal. However, Explore Scientific held up their warranty and RMA'd the eyepiece. (Posted on 12/28/2018)
Review by:
I have been using this eyepiece mainly when I am viewing Galaxies and some larger clusters. The thing you have to keep in mind is that this eyepiece is big and heavy so you want to make sure that your telescope can handle this thing. When I use this I always put it on my 10" Dob. Other than the con of the weight, this is a great eyepiece for galaxy viewing from the material of the glass that this eyepiece is made out of and the great 82-degree field view. (Posted on 12/20/2018)
Review by:
This is one of my favorite oculars. I love using it on the Double Cluster in Perseus. Stars are tight, with no apparent aberrations. Only downfall, it's heavy. (Posted on 12/4/2018)
Review by:
Star aberrations seem very sensitive to eye positioning. When I get my eye precisely centered, star images across the field are crisp and reasonably free of aberration. This requirement, however, makes this a little uncomfortable to use. It's also a huge heavy hand grenade, something to contend with in smaller scopes in terms of needing to re-balance the setup. Overall, though, a very good wide field EP that is worth owning. (Posted on 11/26/2018)
Review by:
I purchased this EP as my first 2". I use it primarily with my Celestron 9 1/4" SCT. I've used it for about a year. It's a great eyepiece. Nice immersive experience. I agree with the other reviews that it's best without glasses. I will be purchasing other Explore Scientific EPs in this family because of my experience with the 24mm. (Posted on 11/25/2018)
Review by:
Great eyepiece with a wonderful wide field of view. The eye position is perfect if you don't wear glasses. (Posted on 11/15/2018)
Review by:
Great field of view and very immersive. Nice flat field with very little astigmatism. Eye relief is tight for eyeglass wearers, but you will see at least as much as you would with a longer eye relief ocular with the addition of being able to "look around" the FOV. (Posted on 10/24/2018)
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