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Using advanced computer design, combinations of low dispersion and high refractive index optical glasses, and durable multilayer deposition coatings, Explore Scientific 52° Series Argon-Purged Waterproof eyepieces are optimized to produce high contrast, high resolution, and superior flat field characteristics. The 52° Series eyepieces are par-focal (meaning they focus at near the same point regardless of the focal length you select) and come with a removable and foldable soft silicone rubber eyecup for the comfort of the observer, and as experienced astronomers know, eye comfort is critical when trying to observe at the visual limits of the telescope.
Protection from the Outdoors - By making the eyepiece body Argon-purged, the waterproof eyepiece internal elements will remain as pristine as the day they were assembled.
Argon atoms are larger than that of Nitrogen and therefore they are less likely to leak or diffuse their way through the seals over the life of the eyepiece. The atomic radius of Argon is larger than Nitrogen by 0.13 angstroms and has a larger atomic volume by 11.2 cubic centimeters/molecule. Argon also has superior inertness vs Nitrogen (i.e. forming few or no chemical compounds with other elements) that prevents adverse reactions with eyepiece components and therefore extends the longevity of the internal components, and also prevents chemical reactions with other elemental contaminants that may be introduced through a weakened seal. And, finally because Argon is less conductive of heat than Nitrogen, Argon cools slower thereby buffering the effects of rapid temperature changes of the optics.
The sealed, dry environment is impervious to internal fogging and contaminants such as fungus growing in between the lens elements. Our waterproof eyepiece is easier to clean, and there is no risk of cleaning solution migrating from the top of the lens and seeping around edges to be trapped in between elements. To insure a perfect seal we test every eyepiece in one meter of water for 30 minutes.
High power eyepieces (e.g. 3mm to 10mm) are used not only for obvious observations of planets and double stars, but can be employed for bright, compact deep sky objects. Not only will the scale of an object like a planetary nebula or globular cluster be impressive as it fills the eyepiece FOV, but the background sky will be very dark as the contrast effect increases with added magnification, provided that the atmospheric seeing conditions are favorable enough to reveal a sharp image. The 3mm is a popular choice for certain telescopes, producing some of the highest magnification views that most astronomers will observe at.
A new focal length joins the Explore Scientific line of inert gas-purged Waterproof Eyepieces with the 3mm 52° Series Eyepiece. A logical companion for the "grab-and-go" ED80mm f/6 Air-Spaced Triplet, this eyepiece produces 160X which will perform very well with good seeing conditions on planetary objects, and to split double stars. On the ED152 at f/8, 405X is achieved without the use of a Focal Extender or Barlow for those nights of near perfect seeing, with a very comfortable 15mm of eye relief.
Comfort, Quality, Value. Most short focal length eyepieces are excellent flat-field multi-element oculars that can transform your visual astronomy experience. With an apparent field of view of 52 degrees, these eyepieces offer incredible value in a very nice eyepiece. Expect exceptional quality and value versus a comparably priced Plossl.
Another great benefit of these eyepieces is the excellent contrast and 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.
|Description||3mm 52° Series Argon-Purged Waterproof Eyepiece|
|Weight||204.1 grams; 7.2 oz.|
|Barrel Size/Type||1.25? O.D. / Double Taper|
|Field Stop Diameter:||2.7mm|
|Coatings:||EMD (Enhanced Multi-Layer Deposition) on all lens-to-air surfaces|
|Lens Elements/ Groups||6 Elements in 3 Groups; Edge Blackened|
|Filter Thread||Fits Standard 1.25-inch Dia. Thread in Filters (1.125-inches x 42 TPI)|
|Waterproof||O-Ring Sealed Argon Gas Purged; Tested Under 1 Meter of Water for 30 Minutes|
|Eyecup||Removable Flip-Down Style Soft Silicone Rubber|
|Lens Caps||Slide-on Top and Bottom|
|Materials||Optical Glass; Aluminum; Steel; Silicone Rubber|
|Markings||Laser Engraved: Focal Length; Series; Serial Number; Brand|