Explore Scientific 8.8mm 82° field argon-purged waterproof 1.25" eyepiece


Availability: More on the way

This 8.8mm Explore Scientific 82° field argon-purged waterproof eyepiece is the right focal length to give you very useful exit pupil sizes and magnifications with all scope types and focal ratios - f/10 Schmidt-Cassegrains, short focal length f/6 refractors, and f/4.5 Dobsonian reflectors alike.
Our Product #: ES8208A
Explore Scientific Product #: EPWP8288-01

Product Description

This 82° 8.8mm Explore Scientific is an excellent medium focal length/ultra wide field eyepiece with an unusual benefit. 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 seven 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 a very wide 82° field of view. The lens edges have been blackened to improve contrast.

The 8.8mm 82° Explore Scientific works with any telescope, from a fast focal ratio reflector, to a catadioptric, to a long focal length refractor. With an 8" Schmidt-Cassegrain, for example, it gives you 227x, a 0.88mm exit pupil (very close to the 1mm exit pupil recommended for high magnification observing under average to good seeing conditions), and a 0.36° field of view (about three-quarters the diameter of the full Moon). With a 10" f/4.5 Dobsonian, it gives you 129x, a generous 1.95mm exit pupil suitable for nebula observing, and an equally generous 0.64° field of view (more than one and a quarter times the diameter of the full Moon). You can use the calculator in the "formula" tab above to see just how wide the field will be with your particular telescope.

At 14mm, the eye relief is surprisingly good for an eyepiece in this focal length range, although eyeglass wearers will still see a somewhat vignetted image. This isn't as much a problem as you might think, as the 82° field of view is so wide that even non-eyeglass wearers have trouble seeing the whole field at once. This is an eyepiece that shows you a "picture window view" of space for a true full-immersion observing experience. With its unconstricted view, your eye relaxes, allowing you to easily use the "averted vision" technique to study faint details across a huge field of view.

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. This link will take you to full details on this unique transferable lifetime warranty.

Tech Details

Barrel Size 1.25"
Eye Relief 14mm
Field of view 82
Focal Length 8.8mm
Number of optical elements 7
Weight 8 oz.
Warranty 1 year, extendable to lifetime


Review by:
I used this all last summer to observe planets. With my 12.5" f4.8 dob (173x), I didn't need to bump the tube as often, because of the wider field of view. Good for double stars also.
(Posted on 1/4/2019)
Review by:
I used this all last summer to observe planets. With my 12.5" dob, I didn't need to bump the tube as often, because of the wider field of view. Good for double stars also. (Posted on 1/4/2019)
Review by:
This was my first wide angle eyepiece. I've been very happy with it. I mostly use it for lunar and planetary viewing on my Mak-Cass. It also provides good views of binaries. The colors seem to be accurate. My location is urban, so those are the most interesting things I can regularly view. (Posted on 12/22/2018)
Review by:
This is one of my most useful EPs. It gives me high magnification planetary views in my C8 and is a good midrange length for my refractors. (Posted on 11/28/2018)
Review by:
This is one of my most useful EPs. It give me high power planetary magnification in my C8, and is a great midrange length for my 80mm APO. Good eye relief and wide apparent FOV. (Posted on 11/28/2018)
Review by:
This eyepiece fit nicely into my eyepiece line between a 10mm and 7mm. I was surprised by the quality - both the build and the performance. Both excellent. Yielding 70X in my 110mm refracter, I use it mainly on open & globular cluster. Stars are pinpoint across the field and the excellent contrast contribute nicely to the view. Very pleased. (Posted on 11/18/2018)
Review by:
Excellent eyepiece for the money. Wide field of view with crisp image and no internal reflections. My only complaint is 8.8mm makes the math harder than 9mm would. But I can live with it. (Posted on 10/6/2018)
Review by:
I bought this eyepiece to replace my old 9MM Nagler type 1. This eyepiece offers every bit as good performance in a smaller package as the old eyepiece. It also cost considerably less cost than a new Nag. This my favortie ep for medium high power in my 16" dob. (Posted on 10/6/2018)
How do you rate this product? *