Agena 1.25" Starguider Dual ED Eyepiece - 25mm

Quite possibly the best series of eyepieces in this price range. Stars are sharp across the field. I've been very involved in amateur astronomy for over 40 years. I've owned 9 different telescopes of all types and quite a number of eyepieces, (I won't even hazard a guess on how many) from inexpensive Erfle's and Kellners to high quality Naglers. In my opinion this series of eyepiece is a top performer and a great value .

Greetings,I spent a good amount of time and research looking for a new, high quality set of eyepieces to replace my older sets from the 1980s. I wanted a first-class, "general purpose" eyepiece set that offered a wide field for DSOs (deep sky objects) and high contrast, well-corrected images for planetary and binary star observing. It was a difficult demand to fill at any price.After months researching optics, I had pretty much settled on a lesser known 5-element design by a Dr. Masuyama. Basically, a refined Plössl or symmetrical eyepiece design with a fifth element interposed between the two doublet lenses. Restricting the number of lens elements is highly desirable in keeping light loss and lens scatter to an absolute minimum for planetary observations, while keeping the design at an economical price. Multi-element, wide field oculars (like Naglers) were specifically designed and corrected for fast f/4.5 ratio Dobsonians. But they are large, heavy, dreadfully expensive and optical overkill. That is to say, over-corrected for more moderate f/ratio Newtonians, slow Catadioptrics, well-corrected apochromats and f/8 to f/15 classical achromatic refracting telescopes.While I found the Dr. Masuyama design (Parks Gold oculars) indeed had superb optics for planetary and binary star work, their 52° fields of view were not much of an improvement over my older 42° Vernonscope Brandon and Unitron orthoscopic oculars. I wanted a less constricted view for DSOs in an effort to enjoy a one "general purpose" eyepiece design of exceptional qualities. It was then that I stumbled onto the Agena Dual ED Starguiders. This 5 & 6-element eyepiece immediately impressed me with its first-class fit and finish, weight and design. Its out-of-the-box quality promised good things to come at the eyepiece and it did not fail.Testing the Agena Dual ED 8mm against an 8mm Vernonscope Brandon ($235) and a 7mm Parks Gold ($140) under the severest binary star tests with a Celestron 6" AVX refractor, the Agena proved to be of equal optical performance with the bonus of a much greater 60° apparent field of view. The Agena 60° field is wide enough for impressive deep-sky observations, and imposing lunar landscapes. The optical quality of the Agena meets all of my observational requirements whatever the astronomical target. Globular clusters are well-defined with stars sharply resolved to the core even at 8mm and 6mm. Orion's Nebula displays wispy tendrils and a wonderful, ghostly 3-D appearance, while its Trapezium E and F stars are easily snared. The most delicate binaries are readily detected. Saturnian moons that might, otherwise, be lost in light scatter are easily detected in a black sky.To quote an optician's review of the Agena Dual ED design:"Each Starguider uses two separate ED (Extra-low Dispersion) glass elements of different glass types in its optical system to provide exceptional color fidelity (with vanishingly low levels of chromatic aberration) so that the true color differences between binary star pairs and planetary surface details are easily visible. Their 60° field of view is very flat, particularly with telescopes f/5 and above in focal ratio. They are uniformly sharp edge-to-edge, with markedly low astigmatism. Barrel distortion is essentially non-existent, eliminating the annoying “goldfish bowl” distortion of the image seen in some eyepieces when panning across a star field.Each air-to-glass surface in a Starguider eyepiece is fully multi-coated for high light transmission and exceptional contrast. The high contrast makes them a good choice for splitting close binary stars, for examining low contrast lunar and planetary detail, and for ferreting out small and faint planetary nebulae against a truly dark sky background. The lens edges are blackened to eliminate internal reflections and further improve contrast."As serious observer of 37 years and a hardcore refractor owner, I demand the best in optics. Agena's Starguider Dual ED eyepieces are truly a "dark horse" ocular design that deserves the highest praise. You will NOT regret owning a set of Agena Dual ED eyepieces. This is an outstanding high resolution design at a very affordable price.Steve Franks