Baader 1.25" & 2" Hyperion Eyepiece - 5mm # HYP-5 2454605

Update 1/15/19I recently spent an entire evening looking at the moon, M42, Betelgeuse, Rigel and Mars with a variety of eyepieces, my fantasy of looking elsewhere shattered by clouds. I compared the Baader Hyperion Aspheric with shorter focal length eyepieces with comparable fields of view, an unfair comparison, but so be it. The telescope was a well-calibrated f6 8" with a finely honed Pegasus primary (Strehl ~ 0.99) and a 1/30th wave secondary from Protostar. The scope and EPs cooled outside from late afternoon. Seeing was average from my relatively dark backyard site.On axis, the 31mm Hyperion was as good as the best of them. When a very bright object (mpon, Rigel) was placed just out of view, there was perhaps a bit more scatter than in much more expensive eyepieces. I noticed the slightest bit of coma for objects at the extreme edge of the field of view that was absent from the other shorter focal length EPs, but this is to be expected. If I focused on an object nearthe edge of the FOV, it appeared sharp and contrasty right across the field of view.Equal to a 31mm Nagler? No. A great value for a "finder" EP? Very definitely.Original post:I used to own Televue and Pentax eyepieces, but the case containing them mysteriously disappeared during a house move. Freed from all that pricey glass, I decided to explore less expensive options to rebuild my collection, hoping that the originals would eventually re-appear. The Baader Hyperion 31mm aspheric replaced a 35mm Panoptic, and honestly, I don't miss it. The Hyperion is lighter, requires no coma correction on scopes f/6 or greater, has a somewhat wider field of view, throws up very bright, very contrasty views even in my somewhat light-polluted back yard, has virtually no internal reflections,and has a very sharp fieldstop. The image quality is notably better than standard Baader Hyperions (which, it should be said, are still an excellent value), more like a Baader Morpheus, IMHO. I experienced a bit of kidney-beaning on first use, but never since, whereas this was a constant challenge with the Panoptic. And it is 1/2 the price! Highly, highly recommended.

At last, I have a full set of these. Been using Hyperion eyepieces for well over a decade 5mm is heavy and tall and it's too much magnification for my small refractor unless conditions are really good, but it is excellent for my larger scope. Unlike my other eyepieces, the 5mm does not break down to be used in my 2inch focuser. Not a deal breaker as I rarely breakdown the others.

I wasn't expecting a tremendous lot from a $200 eyepiece, but this eyepiece is a very pleasant surprise. I got it on the recommendation of an acquaintance who raved about it. He mostly uses TeleVue Ethos eyepieces, and when he told me about this eyepiece, I had to check it out. Once I saw the price, I was ready to be let down, but I ordered it anyway. I have a 9.25" Celestron SCT with a 2" TeleVue diagonal. This eyepiece maintains clarity and chromatic consistency all the way to the edge of the field of view. This size eyepiece is excellent for looking at deep sky objects, and, with a light reduction filter, good for looking at the moon. I have also viewed the sun (through a white light filter) using this eyepiece, but there was very little surface activity, so it was kind of... meh. For me, this is a really good low power eyepiece, and I am very satisfied with it.If you usually go out and spend $$$$ on TeleVue and ExploreScientific super-wide AFOV eyepieces, and you need a good low power eyepiece, I think you might want to check this thing out. It is a lot smaller and lighter than 100- to 120-degree AFOV eyepieces, since there is a lot less glass, but it delivers clear and sharp views.

My wife purchased this for me and I was very surprised and excited to use this. I noticed there was grease on the body of the eyepiece which smudged and removed some of the lettering. So I thought the integrity of the 2" lens group was compromised and promptly contacted the seller Agena Astroproducts who said I could have a day to decide whether to replace the eyepiece or receive a $15 dollar off next purchase. After I hung up, I looked at the 1.25 adapter and took the guard off and noticed 2 deep nicks in the center of the lens group. I called Agena back and they are sending another eyepiece out (awesome customer service) however, I used the eyepiece last night in my 8" Orion Dob and feel I was played from false advertising. The eyepiece does not provide the same magnification from 1.25 to 2" which is why I bought this. Also, my dob is an F/4.8 and I have to look through the side of the eyepiece to even see anything at 1.25", and using the 2" portion the view is obscured like a fish bowl.I did research after I noticed the non-magnification using the 2" portion of the eyepiece here:[...]

There was about 1-2 grams of grease towards the bottom of the eyepiece. It was located where the eyepiece narrows from the 2" to the 1.25" profile. The grease had an orange color and was reminiscent of clean motor oil. I wiped this off with a paper towel no problem. Looking at another reviewers comment about oil no damage to the letters and no imperfections to the optics that I can detect.I did look through the eyepiece and felt that the eye relief was not as generous as the rest of the Baader series. Personally like the 10mm and 24mm the best out of the series.Do note that the leather(?) bag is slightly different as are the woven threads. It looks like a nicer material in comparison to the American offerings of the other baader eyepieces. (International product with German manual/info packets).1 star off for the oil/grease. Everything else was as expected.