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Agena AstroProducts UWA 80° 30mm
| Brand | Agena AstroProducts |
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Overview
Reviews
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Nov 19, 2009
Best in medium to slow F ratios
Pros:Affordable wide field views. Lightweight. Great coatings.
Cons:Field curvature gets worse under f/7. Not for the Moon!
Comments:I purchased the 30mm as well as a 16mm Agena Ultra-Wide eyepiece for my new 8" f/5.9 dobsonian which, unlike my old dob, accepts 2" eyepieces. In the 30mm I wanted a "finder" eyepiece (not for an actual finderscope obviously) for widefield views to quickly locate faint fuzzies. Middle aged eyes and a light polluted sky rules out longer focal length eyepieces, so I was hoping to maximize the field of view without washing out the contrast too much.
Bottom Line: Would you recommend this item? Yes
Now, I'm not expecting an aberration-free eyepiece at that price for an f/6 scope, and some forms of aberration such as edge astigmatism which I get using the Antares 25mm W70 are relatively acceptable. I was initially disappointed with the 30mm Ultrawide - it has one particular aberration in fast scopes that would seem to preclude its intended use, and that is field curvature -- where objects near the edge of the field are severely out of focus relative to the center and vice versa. Many would consider f/6 to be considered a "medium" f ratio. This eyepiece will disabuse them of that notion. In this case f/6 is most definitely "fast".
My initial conclusions above were made during twilight tests on the moon which was definitely NOT the best subject for this eyepiece. More recently I was able to put this eyepiece to effective use on the dob, but more on that in a moment. Below are some other initial tests made with other telescopes...
I might have returned the 30mm (and the 16mm), but I own other scopes, including an 80mm f/7.5 ED refractor. And I got to try it on someone else's 80mm f/7 ED (which is a little faster). The experience with the eyepiece on both these medium focus refractors was vastly improved. Field curvature was only slight at these f ratios with really pleasing wide field views both outside and in the city (the latter with a filter). There is a little chromatic aberration that may bother some. In the 80mm f/7.5 the eyepiece gave a true field of view of 4 degrees (just one degree less than the 50mm finder)!
After reading a review elsewhere of someone using an identical dobsonian who was much more satisfied with its performance, I decided to give it another shot with the f/5.9 looking at actual starfields rather than a twilight moon. Field curvature, while still present and more noticeable than in the refractors, does not come across as so harshly. More importantly, star brightness towards the field edge is not seriously diminished. However, real sharpness is confined only to the middle third of the field of view (assuming one focuses on the center of the field, rather than the edge or elsewhere).
As a "finder" eyepiece, I was able to give it a rigorous task, helping me find NGC 188 under my light polluted sky. I had tried in the past to find it but never being sure I had the right starfield. If you aren't in a dark sky it is an extremely difficult object, and I had only seen it once in a dark sky through a 4" refractor. Now the 30mm in my 8" dob gives a 2 degree true field of view. Along with a newly acquired copy of Uranometria 2000 I was confidently able to identify the field stars even at the edge and even detect the cluster's hazy glow (by the way, I was also using an Orion Skyglow broadband filter that I had previously bought for DSLR photography). Once found I used the 16mm UWA to just glimpse some of the cluster's actual stars. Having accomplished this, I am much happier with the eyepiece than I was initially. It has nice coatings too.
Views of brighter star clusters and the Milky Way give the impression of swimming through space. Yes, things get distorted towards the edge, but with so wide a true FOV, most clusters are confined to the center of the field and are well framed. This is the first eyepiece that has allowed me to fully frame the Double Cluster with an 8" with ample field to spare, albeit a little distorted. The Double Cluster itself remained sharp.
Unless I come into possession of a truly premium eyepiece with perfect center-to-edge fast correction, this eyepiece will definitely do.Jun 7, 2008Agena 30 mm UWA 80
Pros:Very good image quality. Not too heavy.
Cons:The rubber eyeguard is rough and irritates my skin.
Comments:This is a good eyepiece for the money! I have similar UWAs such as the Nagler 31 mm, the 30 mm 1rpd and a 30 mm Widescan II. I purchased the Agena 20 mm UWA and removed the barlow element to use it in the 30 mm mode. I compared it with my other UWAs in my Meade AR5 which is F9.3. It is no Nagler but it outperforms the other UWAs. It is supposed to be the same as the 1rpd but it clearly outperformed it in image quality. Maybe there are production run differences.
Bottom Line: Would you recommend this item? Yes
The image begins to distort about 60% out but the distortion is never very great, even at the edge of the FOV. Since it is not as heavy as the 31 mm Nagler, it is more appropriate for use in my smaller refractors. I used it for about three hours last night and hated to stop.Apr 1, 2008Great Eyepiece
Pros:Great Glass; Great Price; Great View
Cons:None
Comments:This is my first wide angle eyepiece and I love it. The difference from using this and then a smaller field is huge. Everything looks so much bigger and it really gives you a Spacewalk feeling. I love it!!!! I would recommend this eyepiece to anyone looking for a wide field view of the stars....
Bottom Line: Would you recommend this item? YesFeb 27, 2008A great value in a 2" format, wide angle eyepiece
Pros:Nice fit and finish, flawless coatings, undercut barrel, really big field at reasonable price
Cons:Not at its best on fast scopes, heavy
Comments:I finally got a chance to try out the 30mm UW80 I picked up from Agena last night. This is my second 2" eyepiece, the first is the 32mm "Wide Field" Zhumell/GSO that came with the Z12. (I have no idea what design the 32mm is, I've heard plossl and Kellner as suggested in different places)
Bottom Line: Would you recommend this item? Yes
I must say I love the heft of 2" eyepieces. 1.25" eyepieces are fine and I love their compactness, but there is something cool about plugging in what has the same feel as an old SLR 135mm telephoto and seeing the acres of glass on the eye lens. The UW80 is more massive than the Zhumell 32 in this regard.
I like this eyepiece a lot. The eye position is much more comfortable than the Zhumell/GSO. The field is not as flat as the 32mm is at F/5, however I did not need to constantly move my eye about looking for the sweet spot as I do with the 32mm, which has this weird dead zone of darkness I can't quite see but can see anyway. It drives me nuts.
There is a blackout zone on this one as well if you get too close, but this seems to me to come with most, if not all, wide field eyepieces above a 60 degree or so apparent field of view. With the Zhumell/GSO I am constantly hunting for the sweet spot - with this one once you get your eye in place it just works.
On the UW80, coma begins about 60% out from center, but the apparent field is so huge it didn't bother me unless I actually looked directly at the area where the distortion was. In the Z12 this eyepiece fits all of Orion's sword or the entire Pleiades. Since the F/5's impact on the correction doesn't bother me much, I am pretty thrilled.
In the 8" F/7, the image is sharper across much more of the field. About 75% out from center is where the distortion is noticeable. At this point, it was so far out of where my vision seems to concentrate on detail that it was scarcely noticeable while actually looking at anything which is centered up in the field.
Eye position seemed to matter even less at F/7. Bottom line, I like this eyepiece a lot and am glad I picked it up. It has it's flaws at low F numbers yes; however it's comfortable to use and I love the porthole view. In my Zhumell 12 F/5, you get to see all of Orion's sword and a bit more, with a glorious, high contrast M42 tracing filaments all over the place and nebulosity all over the field. Suuuweeet.
This makes my second UW80 along with the 11mm. I like 'em.Oct 26, 2007Agena Astro 30mm UWA EP
Pros:Value
Cons:Softness at edges of field of view
Comments:This is a great EP for the money and it gives beautiful wide field views in a slow focal ratio scope. I haven't compared it to the TV Nagler 31 or UWAN 28 but I'm very satisfied with it. The only problem with it is some softness towards the edge of the FOV. It's a great choice for anyone looking for a budget rich field EP.
Bottom Line: Would you recommend this item? YesAug 28, 2007A real bargain
Pros:Excellent value for slower scopes; Great value for newbies.
Cons:Gets soft at the edges progressively the faster the scopes get.
Comments:For the modest price, this EP performs well. But keep the price in mind.
Bottom Line: Would you recommend this item? Yes
I was looking for public star party eyepieces and wanted a WOW fov as so many people use plossls for public use and nobody says WOW. This eyepiece is very good almost to the edges at F15, not quite as good at F10 and slightly weaker performance in a F7 FD APO refractor. At F7 the outer 20% is out of focus. But remember the price!!!
This does not compete with a Nagler, Uwan or UWA !!! But at this price and performance I will add more for star party use and would not hesitate to recommend for a low budget observer using slower scopes.Mar 30, 2007AgeenaAstro UW80 30mm
Pros:Image sharpness and Pinpoint stars to the edge of view; Price was great.
Cons:Eye relief is pretty tight
Comments:I bought this after doing some research for a cost effective wide view 2" eyepiece. I found this to be the same e.p. as the the 1rpd and Moonfish for a little less. I purchased it and absolutely love it. I have used it in C11 and C8 SCT scopes. The stars are pinpoint even out to the edge of view. I compared the views with this e.p. and my friends 31mm Nagler in a C11 and was very impressed with the Agena e.p. I really had a hard time detecting any difference in image sharpness. The Nagler image had a slight edge in contrast. The Agenna was close on eye relief as it would blackout if you didn't keep your eye in a certain spot but once you got used to the sweet spot it was not an issue. This has got to be one of the best kept secrets in a UWA e.p. for a SCT or long focal length scope.
Bottom Line: Would you recommend this item? YesSort by
