Orion Expanse Wide-Field 20mm

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Brand and Model:Orion Expanse Wide-Field 20mm
Price ($USD):$49.95
Type:Misc Wide Angle
Focal Length:20 mm
Barrel Size:1.25
Apparent FOV:66.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:17 mm
Elements:4
Weight (lbs):
Description:Eyepieces for Those Extra Wide Open Celestial Spaces
With their 66 deg. apparent field of view, our Expanse wide-field eyepieces will definitely turn up the Wow! factor in your deep-sky observing experiences! Imagine taking in objects like the Andromeda Galaxy, the Double Cluster, or the star clouds in Sagittarius in one sweep! With an Expanse in your focuser, you can!

Expanse oculars have big eye lenses and great eye relief (13mm to 17mm). Eyeglass wearers can view the entire field without removing their glasses. All eyepiece elements are fully coated, with the outer lens multi-coated for additional light transmission. Each 1.25" aluminum barrel is threaded for filters and internally blackened to eliminate internal scattering. And their fold-down rubber eyeguards enhance contrast by blocking stray light.

With our Expanse eyepieces you get a super wide field of view and superior optical performance. And check out the price. You also get a bargain!


Orion Expanse Wide-Field Eyepieces Page

Vote Highlights Vote
Orion Expanse Wide-Field 20mm
Some coma in faster scopes, but very good contrast. Excellent for the price, they beat out many of my more expensive EP's.

Overall Rating: 8
Optics:7 Value:10
Weight: 7 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=419915

Orion Expanse Wide-Field 20mm
Very nice eyepiece for the price. I got mine from scopestuff.com who sells the same eyepiece for ALOT less money.

Optics in mine were reasonably sharp in both a 90mm f/11 refractor, and in an 8" f/5 newtonian. In the newtonian there is more curvature towards the outer edge, but no seagull effect until the very edge (outer 5% or so.) Is it a Nagler? Of course not, but it is a very nice eyepiece for the price. I much prefer it over any Plossl in this focal length just for the sheer wide FOV.

Overall Rating: 7
Optics:8 Value:9
Weight: 6 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=241938

Orion Expanse Wide-Field 20mm
Very good introductory wide-field eyepiece. It was the 20mm that got me hooked. I've moved on to more expensive designs, but these are still a very good value. Yes there is coma in faster scopes, but it's not overpowering at f4.7 or less.

Overall Rating: 9
Optics:8 Value:10
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=595166

Orion Expanse Wide-Field 20mm
Just received it the other day. Nice looking and size and weight are very managable. The afov is almost identical to my 15mm Panoptic so the advertised value is correct.
First used with my 8" f/6 dob. Initial view of Vega was very sharp in the center with good contrast, but the outer 50% is commatic, and not totally due to my f/6 optics. Next I barlowed it on the Double-Double and the pairs split nicely. The outer fov was expectedly sharper with the barlow.
Next I drug out my 4" f/10 refractor. As expected the images were sharper at the edges but not by much. The only other eyepieces of a longer fl that I have are both plossls and neither are very sharp as well. I was hoping the 20mm Expanse would be much better than it is. I will probably keep it for the time being as I do like the wider fov as compared to the plossls.
For 50 bucks it is a reasonable value but I guess I'm going to have to bite the bullet and get a wide field 2" in the Televue or Konig variety to get the edge sharpness that I want

Overall Rating: 7
Optics:7 Value:7
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=146264

Orion Expanse Wide-Field 20mm
Comparable to a Sirius Plossl but with a wide view. From $39 to $55 price range, these are the best deals in ameatur astronomy. On my f4.5 there is comma at about 70% out but I use the edges just to locate objects.

Overall Rating: 9
Optics:8 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=348068

Orion Expanse Wide-Field 20mm
Nice eyepiece. I won it at a star party raffle. I also have the 15mm. I probably would not have bought it since I have a 19mm panoptic and it is more or less a duplicate. That said, it barlows very nicely and works well on planets and for deep sky observing. I will keep it to use at star parties and public nights. Larger field makes it a winner over plossels.

Overall Rating: 8
Optics:7 Value:9
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=313114

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