52° Series 4.5mm Waterproof Eyepiece

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 4.5mm is a popular choice for a wide variety of telescopes, producing some of the highest magnification views that most astronomers will observe at. Explore Scientific Waterproof Eyepieces - Comfort, Quality, Value. The Explore Scientific 52° Series 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. Item Number EPWP5245–01 Focal Length 4.5mm Length 83.5mm Width 43mm Weight 181.4 grams; 6.4 oz. Barrel Size/Type 1.25" O.D. / Double Taper Eye Relief 15mm Field Stop Diameter 4.1mm 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