Orion Expanse Wide-Field 9mm

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Brand and Model:Orion Expanse Wide-Field 9mm
Price ($USD):$49.95
Type:Misc Wide Angle
Focal Length:9 mm
Barrel Size:1.25
Apparent FOV:66.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:16 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

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Orion Expanse Wide-Field 9mm
Some coma in faster scopes, but very good contrast. Excellent for the price, they beat out many of my more expensive EP's. This and the 6mm are the best of the line.

Overall Rating: 9
Optics:9 Value:10
Weight: 7 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=419917

Orion Expanse Wide-Field 9mm
I wanted to replace my venerable 9mm UO ortho with something with longer eye relief. Based on the low price and mixed reviews of this eyepiece, I was wary. So, I picked up both this unit and a 9mm Vixen Lanthanum.

In a side-by-side comparisons with the 9mm Vixen and 9mm UO ortho (all barlowed in a 6" f/5 Newtonian), the Expanse has held its own quite admirably. It's images nearly as bright as the orthos and sinificantly brighter than the Vixen's (lots of glass there). It was sharp over just about 80% of the field - but this is similar to the smaller usable fields of view in the ortho and LV. Eye relief is generous, although this makes positioning your eye a little tricky compared to the Vixen with its larger eyecup. The only place it slipped was in contrast, which was lower than both the ortho and the Vixen.

What did this mean in practical terms? The Expanse excelled on deep sky, particularly the Lagoon, Swan, Dumbell and Ring nebulas and also did well on globulars and open clusters. Contrast was not as good as the LV, but the images were significantly brighter and the FOV wider. For example, the LV resolved individual stars in globulars more precisely, while the Expanse was slightly less sharp but brighter. On nebula, the dimmer LV with better contrast and brighter Expanse with less contrast were very close. With a nebula filter added, the brighter and wider Expanse image equalled the LV.

I was also surprised with the Expanse's on-axis planetary performance. Off axis it does ghost, and there is significant ghosting on the Moon. But on axis it is sharp and clear. Both the ortho and the LV are supposed to be much better planetary eyepieces, but try as I might, I couldn't make the Expanse fall far behind them. Detail on Jupiter was just as sharp and the shadow of a Europa transit actually was blacker and sharper in the Expanse. Then I turned them on Mars over several nights in late June. I kept trying to convince myself that I could see more in the LV than in the Expanse, but it just wasn't so. In fact, I could consistently see equal or a little more detail in the Expanse.

Bottom line - I was planning to keep the LV, but I'm going to hang onto the Expanse into the fall to test the two on Jupiter and Saturn. We'll see who's the keeper then. Until then, at $49 new and $40 used, you can't go wrong with the Expanse.

Overall Rating: 8
Optics:8 Value:9
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=258109

Orion Expanse Wide-Field 9mm
Again, the 6 and 9 mm versions of this eyepiece are far superior to the 15 and 20 in fast scopes. I own a 13.1 coulter and a Nexstar 5 and need a widefield that is useable, and affordable in each scope (an f/4.5 and an f/10). finding decent affordable widefields is tough and these do well. Not as contrasty as plossls or otrhos but a wider field. Mine are from Burgess Optical and I needed a filter extender on the 9 to prevent the lowest element from scratching the filter when screwed in. Good all around but some ghosting on bright objects.

Overall Rating: 8
Optics:7 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=329348

Orion Expanse Wide-Field 9mm
Great eyepiece. Great for DSO. There is glare on planets and the moon. Also some blackout whick may be annoying if you wear glasses. Never use my siebert standards any more.

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=274301

Orion Expanse Wide-Field 9mm
Not as sharp anywhere as an equivalent plossl. Difficult to hold view due to blackouts. Was never able to find a position to wholly eliminate edge kidneybeaning. Field doesn't seem like it is 66 degrees due to difficulty in holding view.

Overall Rating: 7
Optics:7 Value:7
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=221208

Orion Expanse Wide-Field 9mm
great eyepiece... i also have onde meade series 4000 (15mm) and the orion gives me the same field in the sky but with the double of the amplif.

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=174970

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