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Baader Planaterium Hyperion 13mm Eyepiece

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I am relatively new to astronomy but wanted to add some capability to my Orion XT8 scope. The Orion comes with two moderate quality Colossal lenses, a 25mm and a 10 mm. While the views through the 25mm were generally satisfying the 10mm had a very narrow field of view and was not at all sharp near the edges. After some research I decided on the Hyperion series of lenses and the 13mm seemed to be about the right focal length for my viewing. These are 68 degree FOV lenses and claim to very superior coatings. If you are familiar with the Orion Stratus Series of Eyepieces these appear to be very similar but with two important differences. One is the previously mentioned improved multicoatings. The second is a good selection of afocal camera adaptors and extension rings. These extension rings allow you to fine tune focal length over the range of 19.7 to about 30mm. The lens is basically composed of 8 elements in 6 groups. The last group functions much like a Barlow lens improving the power of the eyepieces without much downside.

These are large eyepieces. The 13mm weights about 13 ounces. As a visual eyepiece, I have found the Hyperion's deliver superb sharpness and color fidelity across their 68° wide, flat-field, even in faster telescopes. In my comparisons to the Orion Plossls the Hyperion excelled in every regard. From their superb on-axis and off-axis sharpness, to their pitch-black high contrast field, the Hyperions really work. Viewing through a Hyperion is notably comfortable and relaxing, due to their forgiving eye-position, 20mm of eye-relief, extra-large eyelens, and an optical design that is free of annoying 'kidney-beaning' and blackouts. This has become my favorite lens for most viewing and the wide field of view allows me to use it where I would ordinarily have to use the 25 mm Plossl to get adequate coverage.

The eyepieces are not very expensive either- right now they are going for $119 in most focal lengths.

The only downside that I have found is that the weight means the scope will sometimes settle a little since it is not balanced as well. I solved this by tightening the springs on the XT8 slightly.


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