University Optics Super Erfle 25 mm


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Brand and Model:University Optics Super Erfle 25 mm
Price ($USD):89.95
Type:Modified Erfle
Focal Length:25 mm
Barrel Size:1.25
Apparent FOV:60.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:0 mm
Elements:5
Weight (lbs):~12 oz
Description:

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University Optics Super Erfle 25 mm
Unlike Mr. Gibson's review I wasn't as pleased with my 25mm Super Erfle. Color correction is very good, better than a average plossl. However, my biggest complaint is the astigmatism starting at around 70% at the edge of FOV in my F11 refractor - and it's worse in my F6 MN56 Mak-Newt and F7 APO. The stars aren't pinpoints, but starting to look either squashed or like crosses. I didn't find the field as flat as Mr. Gibson stated in his review of his sample.
Overall, an average value knowing that some of my comparable plossls work much better with almost wide FOV. I just expected a bit more.

Overall Rating: 6
Optics:7 Value:5
Weight: 5 (Veritable Vote)
Date:
By: wprince
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=452878


University Optics Super Erfle 25 mm
[Note: Vote moved from description by webmaster]

I took the time last night (6/12/04) to compare the 25 mm UO Super Erfle EP with my 24 Tele Vue Wide Field, as it's close in focal length to the 24 mm TV WF. The TV WF's are said to be the "poor man’s Pan Optics". I find I use my 3, TV WF’s 15 mm, 19 mm, and 24 mm the most for DSO’s. I’ve been very happy with them for several years now.

Again, I like the look and feel of this UO Super Erfle as I’ve compared the 16 mm & 20 mm Super Erfles prior to this 25 mm UO Super Erfle. It's well made and solid, and a bit larger than the 16 mm, and 20 mm Super Erfles. The UO Super Erfles are made by the same folks in Japan that make both lines of the UO Ortho's. It’s fully multicoated and uses “better optical glass”. It's about the same heft as the 24 mm TV WF but not in girth or as heavy. It also comes with 2 dust caps. There is no field stop on this EP the same with the 16 mm, 20mm Super Erfles, and putting it in the focuser and looking threw it showed it doesn't need one either. There is a clear and clean definition of the end of the FOV. The scope I used for this test was a 4" f/13 refractor. M13 was the target object in the EP. The UO Super Erfle 25 mm comes to a razor sharp focus with crisp pinpoint stars. The edge of the FOV looks sharp and centering a brighter star in the FOV. I slowly slewed the star to the edge of the FOV. It got slightly soft in the very last 1-3% of the FOV. I saw no field curvature, no ghosting, or sky glow reflected in the eye lens. I saw no black out either. It's a very comfortable EP to use with about 14-17 mm of ER. I'm an eyeglass wearer; with my glasses on I could see the entire 65* FOV.

OK now the Tele Vue Wide Field 24 mm goes in the focuser. A slight refocus and the same razor sharp focus with crisp pinpoint stars as the 25 mm UO Super Erfle all though it does yet again seem slightly dimmer across the FOV compared to the UO 25 mm Super Erfle. The edge of the FOV looks sharp and centering a brighter star in the FOV. I again slowly slewed the star to the edge of the FOV of the 24 mm TV WF. It got slightly soft in the very last 3-5% of the FOV. I saw no field curvature, no ghosting, or sky glow reflected in the eye lens. I saw no black out either. My trusty 24 mm TV WF’s has been my observing standard EP’s due to its very comfortable views. It’s got about 14-17 mm of ER and is great for eyeglass wearers as you can see the entire FOV. Only drawback is folks don’t put them up on astromart often so getting one is hard, as they are no longer made.

Conclusions:

I’ve found a worthy EP that compares to my beloved 24 mm TV WF. I have no qualms recommending this EP to anyone that wants a comfortable EP to use that is very made well and provides high quality views like a 24 mm TV WF. Also, it’s currently a bargain at $89.95. I’d be interested in reading about some ones comparison to a 24 mm Panoptic.


Clear skies,

Mark Gibson
President ASSNE
Owner ClearVue Optics

Overall Rating: No Vote
Weight: 5 (Veritable Vote)
Date:
By: Anonymous (xxx.xxx.104.101)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=365156

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