- Explore Scientific 100° Series Waterproof Eyepieces -


purchase description field stop dia eye relief size weight
Dealer or Buy Now #EP1009-00 - 9mm 100° WP Eyepiece; 2.0-inch 15.7mm 12.5mm L=145mm x W=60mm 602 grams; 21.2 oz
Dealer or Buy Now #EP10014-00 - 14mm 100° WP Eyepiece; 2.0-inch 24.4mm 14.5mm L=157mm x 70mm 836 grams; 29.4 oz
Dealer or Buy Now #EP10020-00 - 20mm 100° WP Eyepiece; 2.0-inch 34.8mm 14.5mm L=156mm x W=70mm 968 grams; 38.1 oz
Dealer or Buy Now #EP10025-00 - 25mm 100° WP Eyepiece; 2.0-inch 41mm 14.5mm L=140mm x W=73mm 1177 grams; 41.5 oz
Summer 2013 #EP10030-00 - 30mm 100° WP Eyepiece; 3.0-inch 52.2mm 19mm L=200mm x W=107mm 2353 grams; 82.9 oz

Go Hyper-Wide & Experience the Vastness of Space Like Never Before


The Explore Scientific 100° Series™ eyepieces are hyper-wide class oculars that can transform your visual astronomy experience. You may be startled at the amazingly wide expanse of inky black sky you behold the first time you bring your eye to a 100° Series eyepiece, and after awhile, you may even forget that you have an eyepiece between you and the universe! With an apparent field of view that is close to the maximum for hyper-wide eyepiece design, objects are not only easier to locate, but for non-driven telescopes the object will stay in the field of view for a very long time before any adjustments need to be made.

Another great benefit of hyper-wide eyepieces is the ease with which you can gaze, not directly at an object, but slightly to either side. This skill, called using averted vision, is especially helpful when observing faint objects, because using averted vision puts the image on a part of your eye that is more sensitive to light, allowing you to see fainter images.


Explore Scientific 100° Eyepiece Highlights


Optimized Optical Design Explore 100° Series hyper-wide eyepieces are optimized through each design, fabrication, and testing process to produce flat-field images that have high contrast and resolution.


Exotic Glass Combinations for Optimum Results Eyepieces are constructed of 8 or 9 lens elements (depending on the focal length) that are fabricated from combinations of Dense Crown, Light Crown, Dense Flint, and Lanthanum optical glass.


Durable Coatings & Finishing Touches Each element in your Explore Scientific 100° eyepiece is fully multi-coated, resulting in bright, sharp images, and every element has blackened edges to reduce internal reflections and increase contrast.


Waterproof, Fog-Proof Housing The internal optics of all 100° Series eyepieces are housed in a gas-purged, waterproof barrel that keeps them as pristine as the day they were manufactured. Cleaning is much easier, and there is no need to worry about water or fluid becoming trapped in between elements due to rain, spills, heavy dew, or getting over-enthusiastic with lens cleaning fluid.


Hyper-Wide Field Experience The 100° experience is different than that of more conventional eyepieces. A hyper-wide field of view means you can see more of the night sky at once, allowing you to observe larger or closer objects in their entirety, or to easily use inverted vision to capture faint photons of light. Also, those using Dobsonians or other instruments without a motor drive will enjoy watching an object drift more slowly across the field of view. Manually moving your telescope to compensate for the rotation of the Earth will be required much less frequently, and that's a good thing.


Tapered 2" Barrel for Extra Security The insert barrel of each eyepiece is double-tapered to allow smooth insertion to, and removal from, a telescope's eyepiece holder or diagonal, however the wide dimension of the taper helps prevent the eyepiece from falling out of the telescope should the set-screw holding it in place become loose. The 2" barrel is threaded to accept standard screw-on filters.


Optional Focal Extenders for Extra Magnification Explore Scientific makes a wide variety of eyepiece focal lengths, allowing a change in magnification for just about any observational study you can think of. However, if you would like to get "double duty" out of the eyepieces in your accessory case, while still retaining the eye relief of that eyepiece, use Explore Scientific Focal Extenders.



Producing optics for amateur astronomers that can be relied upon to deliver research-quality images requires a solid design, careful fabrication, multiple tests, and continued diligence to make sure we are always doing everything we can to produce a cutting edge, quality product. This is what we do at our facilities at Explore Scientific, and to insure your satisfaction, we back each eyepiece with the Explore STAR Transferrable, Extended Life of the Product Warranty, so you can keep exploring!



Explore Scientific Eyepieces are Gas-Purged and Waterproof to Make Cleaning Easy


Cleaning Waterproof Eyepieces


While a few dust particles on optics will not affect visual or photographic performance, there comes a time when your eyepiece will become dusty or dirty enough to affect contrast. When cleaning your standard eyepieces great care must be taken to keep water or other liquids from seeping into the elements, but not so with Explore Scientific Waterproof Eyepieces. Since our eyepieces are completely waterproof and fog-proof (we test them by submerging in one (1) meter of water for thirty minutes), they can be washed under running water, and optical cleaning solutions can be applied directly to the optics without worry. Remove the soft rubber eyecup and use the same techniques that you would use to clean a telescope's primary mirror. After a final rinse in pure distilled water and dried with compressed air, you can clean these eyepieces with professional results to the very edges of the external lens elements.

Explore STAR Extended and Transferrable Life of the Product Warranty


Explore STAR Warranty


We are always striving to improve the quality of Explore Scientific eyepieces and to enhance your experience as a user of our products. This is why we created the Explore STAR Transferrable Extended Life-of-the Product Warranty Program.


For as long as we manufacture a product it is under warranty, no matter how many times it is sold or traded to another individual. And when we stop manufacturing a given model (which is the end of the Life of the Product), we will extend the warranty automatically for another five years.


Learn More about Explore STAR Warranty

Review of Explore Scientific's Focal Extenders


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