Product Description
This 82° 7mm Astro-Tech UWA eyepiece is an excellent short focal length/ultra wide field eyepiece with an outstanding price.
The optical designers used the latest computer design programs to optimize its performance. Its seven element/four group design uses low dispersion and high refractive index lenses and full multicoatings for high contrast, high resolution, and flat field images across a very wide 82° field of view. The lens edges have been blackened to improve contrast. The eyepieces are parfocal within the UWA series.
The 7mm 82° Astro-Tech works with any telescope from a fast focal ratio reflector to a long focal length refractor or Maksutov. It's particularly good with Dobsonians and fast focal ratio refractors, providing high magnification with a very wide field of view for observing smaller globular clusters and compact nebulas.
At 12mm, the eye relief is good for such a short focal length eyepiece, although eyeglass wearers will still see a somewhat vignetted image. This isn't as much a problem as you might think, as the 82° field of view is so wide that even non-eyeglass wearers have trouble seeing the whole field at once. This is an eyepiece that shows you a "lost in space" view of space for a true full-immersion observing experience. With its unconstricted view, your eye relaxes, allowing you to easily use the "averted vision" technique to study faint details across a huge field of view.
The eyepiece has a soft fold-down rubber eyecup and comes with dust covers for both ends of the eyepiece.
Tech Details
| Barrel Size | 1.25" |
|---|---|
| Eye Relief | 12mm |
| Field of view | 82 |
| Focal Length | 7mm |
| Number of optical elements | 7 |
| Warranty | 1 year |
Reviews
I spent an evening using this in my AT102ED, also from Astronomics. My main concern was the sharpness of stars across the entire field in this f/7 scope. I was not disappointed; edge-edge the stars were pinpoint. I could also just get the entire Double Cluster in one view @102x. The Moon almost filled the view and also was sharp across the face. I was just barely able to split the Double Double in Lyra at times. This eyepiece gives me a 49' FOV at 102x and I plan to sell two other eyepieces that this replaces.
Seeing improved a bit so I opted to put this in a 2x Barlow, giving me 204x; really the limit for a 4" scope. Again, looking at the Double Double I could easily see gaps in both binaries and nice round stars anywhere in the view. M57 was faint because of the almost-full Moon, but I readily saw the smoke ring shape with the center hole.
My only complaint is the lack of an adjustable eyecup. But, I found that the position of the fixed one was good for 90% of the time. Is this on par with the Green Goodies that are an informal benchmark...not quite. But, for the price of one excellent eyepiece you can get 3 very good ones in this series and be quite happy with them. I am now looking at another one to fill a gap in my eyepiece spectrum. (Posted on 10/10/2022)
