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GSO 1.25" 2.5x Apochromatic Barlow Lens # BL251

4.8 (38 Reviews) Read Reviews Write Review
Brand GSO
Part Number BL251
Availability available

Product Info

Manufacturer Description

If you need more power than your eyepieces alone can provide, we offer a new apochromatic 2.5x Barlow lens from GSO (Guan Sheng Optical) to give a big magnification boost to any 1.25" eyepiece it's used with.

Nothing has been compromised in GSO's latest and finest offering. This Barlow features an air-spaced, three-element, apo design with fully multicoated optics. The housing is precision machined from aluminum stock and black anodized to a hard finish. The lens edges and inner barrel are blackened to provide maximum contrast. The Barlow body includes a brass compression ring so that your eyepiece barrels are not marred by the captive set screw. The 2.5x model has a clear aperture of 23mm. For those who need a very high quality Barlow for all-round use, the 2.5x barlow is a very nice step up from the typical 2x achromatic barlows commonly found on the market.

Specifications:

  • Barrel size = 1.25" (31.7mm)
  • Magnification factor = 2.5x
  • Weight = 3.5oz (99gm)
  • Total height = 2.95" (75mm)
  • End caps = 2
  • 1.25" filter threads on bottom of barlow: No
  • Made in Taiwan

Reviews

4.8 (Based on 38 Reviews) 95% of reviewers recommended this product.
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    1. Collin

      Collin New Member

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      Review by Collin S.
      1549864713
      Feb 10, 2019

      5.0 Excellent value!

      Pros:

      Cons:

      Comments:

      I compared the GSO 2.5x apo barlow to a TeleVue 2x I had. First, this barlow functions as a 2.1x barlow, not a 2.5x. In any event, on Almach, the beautiful pair was easily separated in my 17mm Sterling Plossl and looked simply beautiful, orange primary and light blue secondary. But with the same eyepiece, the TV 2x barlow put up two dull, barely colorful stars. Maybe they were sharp, but dull and washed out doesn't cut it for colorful double stars. Sold the TV 2x and the GSO 2.5x apo barlow has a permanent spot in my eyepiece case now.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    2. Guest

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      Review by John G.
      1526249695
      May 13, 2018

      5.0 GSO barlow

      Pros:

      Cons:

      Comments:

      Fit and finish as good as any higher priced brand barlow.
      Optically does a quality but not premium quality job.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by PATRICK L.
      1523430894
      Apr 11, 2018

      5.0 Je suis très satisfait de

      Pros:

      Cons:

      Comments:

      Je suis très satisfait de cet achat.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    4. Guest

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      Review by David L.
      1522884144
      Apr 4, 2018

      5.0 GSO Barrlow

      Pros:

      Cons:

      Comments:

      Very good glass and build quality.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    5. Guest

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      Review by Jason H.
      1496161022
      May 30, 2017

      5.0 Very satisfied

      Pros:

      Cons:

      Comments:

      This piece makes a big difference in the size of the planets, very impressive.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    6. Guest

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      Review by Sergio M.
      1490928700
      Mar 30, 2017

      5.0 Barlow Lens

      Pros:

      Cons:

      Comments:

      Excellent product. I am very satisfied.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Jason H.
      1484772113
      Jan 18, 2017

      5.0 Good Barlow

      Pros:

      Cons:

      Comments:

      I have compared this barlow with a 2.5X powermate and it compares very favorably. The powermate performs a little better but not enough to warrant the extra cost. I use it with my mak to get good planetary views with my plossl eyepieces.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    8. Guest

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      Review by Blowfeld of Liverpool, UK.
      1463356800
      May 15, 2016

      5.0 Fantastic!

      Pros:

      Accurate,Compact,Lightweight,Quality Lenses,Strong Construction,Easy to Use

      Cons:

      Comments:

      Very easy to use and, when combined with a 10 mm eyepiece, the Barlow excels in fine focus. Best additional purchase to my new 6" Dobsonian.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    9. Guest

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      Review by registered alien of Registered alien Osaka Japan.
      1459814400
      Apr 4, 2016

      5.0 How wonderful Barlow great optical quality

      Pros:

      Quality Lenses,Lightweight,Accurate,Compact,Strong Construction,Easy to Use

      Cons:

      Comments:

      This is a really great Barlow. I've had much more expensive models which are very good but I think this one is better optically and its more compact, lighter weight, so easier to use ....the screw is a little bit funky but it works very well and at least it has the brass band inside so it doesn't scratch up eyepieces.... I use this with my 58

      Bottom Line: Would you recommend this item? No
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    10. Guest

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      Review by TomH of Crossville, TN.
      1454630400
      Feb 4, 2016

      4.0 Great Price

      Pros:

      Strong Construction,Quality Lenses,Lightweight,Easy to Use,Accurate

      Cons:

      Comments:

      Good three element barlow for the money.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    11. David Keller

      David Keller New Member

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      Review by Dewi of Alexander, NC.
      1427500800
      Mar 27, 2015

      5.0 Clear and sharp magnification

      Pros:

      Lightweight,Compact,Quality Lenses

      Cons:

      Comments:

      This GSO barlow is the best I have found for general use. I use Explore Scientific and TV eyepieces and this barlow magnifies without significant reduction of brightness or clarity. For the price you can't beat this barlow.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Ray the StarGeezer of Modesto, CA.
      1427500800
      Mar 27, 2015

      5.0 Very Good Barlow

      Pros:

      Lightweight,Easy to Use,Strong Construction,Accurate,Compact

      Cons:

      Comments:

      I call this a very good barlow. If I could, would give it 4.5 stars for performance (but I rounded up, so it gets 5). Not perfect on all targets with all eyepieces but very satisfactory on nearly all. The ergonomics are very good, fit and finish excellent. No gripes for the price. Used in a 5.5" refractor.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Herb of Irvine CA.
      1413763200
      Oct 19, 2014

      5.0 Excellent Barlow for the Price!

      Pros:

      Accurate,Quality Lenses,Compact,Strong Construction

      Cons:

      Comments:

      Very nice Barlow.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Jeff of Conroe, TX.
      1408320000
      Aug 17, 2014

      5.0 Good quality

      Pros:

      Easy to Use,Quality Lenses,Lightweight

      Cons:

      Comments:

      I use this on my refractor and my MAK. It has nice glass and pulls in the views. No need to pay more.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    15. Guest

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      Review by Herb of Irvine CA.
      1408147200
      Aug 15, 2014

      5.0 Excellent Barlow!

      Pros:

      Compact,Strong Construction,Quality Lenses

      Cons:

      Comments:

      Excellent quality ... compared it to several more inexpensive Barlows (including an Omni 2x) and this one is the best and sharpest. Very happy and well worth the money!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    16. Rdamer726

      Rdamer726 New Member

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      Review by rd726 of Indiana.
      1386374400
      Dec 6, 2013

      4.0 Nice

      Pros:

      Easy to Use,Quality Lenses,Compact,Lightweight,Strong Construction

      Cons:

      Comments:

      Nice shorter Barlow that works great. For most of my eyepieces it more along the lines of 2.2x than the listed 2.5x but that is what happens with most Barlows.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    17. dogstar

      dogstar New Member

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      Review by Starthrower of NH.
      1374969600
      Jul 27, 2013

      4.0 Great quality, performance and price

      Pros:

      Strong Construction,Easy to Use,Lightweight,Compact,Quality Lenses

      Cons:

      Comments:

      This barlow offers a quite useful alternative to the 2x and 3x standards. Very nice build quality and so far great performance. I may have rated it five stars had I used it more, but so far on lunar work its seems to offer no apprecialble loss of clarity or color fidelity. Agena's delivery was breathtakingly fast, as usual, which is why I try to order from them whenever I can. In short, excellent product for the price, with fast delivery.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    18. Guest

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      Review by Dan of Gaithersburg, MD.
      1369958400
      May 30, 2013

      5.0 Great Barlow for the price

      Pros:

      Quality Lenses,Strong Construction,Easy to Use

      Cons:

      Comments:

      I use this a bit for visuals on planets, but where it's really helped is with planetary imaging. I use this in my 900mm focal length refractor and an imaging source planetary cam and have been really impressed with the images I've been able to get. I've shot Saturn with that set-up, and get clearly defined bands on the planet as well as a very clear Cassini division in the rings. Very happy with this barlow!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Eddie of Brazil.
      1363996800
      Mar 22, 2013

      4.0 Good Barlow for the price

      Pros:

      Cons:

      Comments:

      Nice Barlow, with good contrast at low to medium magnifications. The barrel is very well machined. In summary, very good value..

      Bottom Line: Would you recommend this item? No
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Gustavo of Isabela, Puerto Rico.
      1348272000
      Sep 21, 2012

      5.0 Great for planetary imaging

      Pros:

      Quality Lenses,Compact,Accurate,Easy to Use,Lightweight,Strong Construction

      Cons:

      Difficult To Focus

      Comments:

      I use it for imaging planets with my C8 SCT and NexImage CCD. It gives a focal ratio of F/25, which I think is about the maximum that I am willing to go with that scope. The barlow looks like a quality item, and performs perfectly.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by Bob the Burglar of Petaluma, CA.
      1340755200
      Jun 26, 2012

      4.0 Better than Expected

      Pros:

      Lightweight,Compact,Quality Lenses,Accurate,Easy to Use,Strong Construction

      Cons:

      Comments:

      The seeing conditions on 6/23/2012 were great where I live, so I took my C8 out and aimed it at Saturn. I checked this Barlow out with every eyepiece I have and the results were fantastic. I even used it with my Televue 8 mm EP and the view of Saturn was still fantastic. I decided to aim at Arcturus and see if I could get an Airy disk, but seeing was not quite good enough to get a stable image. There is only one drawback. My Celestron 26 mm Plossl (made in Taiwan) wouldn't fit into this Barlow (also made in Taiwan) but my 32 mm Omcon Plossl (made in the same factory as the Celestron EP) did fit. Well...nothing is perfect, but this Barlow is a great deal, and great service from Agena.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    22. Guest

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      Review by Jim of Colorado.
      1335744000
      Apr 29, 2012

      5.0 Fantastic value!!

      Pros:

      Quality Lenses,Easy to Use,Accurate,Strong Construction

      Cons:

      Comments:

      I got this for my Astroscan. The rings of Saturn look fantastic. Great product,

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    23. spit

      spit New Member

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      Review by jonastro of Greensburg, PA.
      1320451200
      Nov 4, 2011

      4.0 GSO 2.5X barlow

      Pros:

      Strong Construction,Accurate,Easy to Use,Lightweight,Quality Lenses,Compact

      Cons:

      Comments:

      I have a 2X antares APO barlow (celestron ultima clone)- I needed a bit more image size to image the planets, I had a 2.8X klee that worked great at the right EP power for visual, but was too much imaging and never gave a sharp focus, I was leary at 1st about this barlow and the price, but I ordered it anyway - agena shipped it immediately, upon arrival the barlow and coatings looked great!- I hear say the ultima is more a 2.2X ( though I cant say)- however the GSO does gives a larger image scale as a 2.5X would, what surprised me is- it has better color correction and is sharper than my antares- this barlow is truely a fantastic buy!- the only reason I gave it a 4 star is because it's not a powermate, don't take it the wrong way about the barlow, I'm so satisfied with the quality, I wont even consider spending over 3X the cost for the televue

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    24. Guest

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      Review by Philippe of Meaux - France.
      1319846400
      Oct 28, 2011

      4.0 Lens and design quality for a good price

      Pros:

      Strong Construction,Quality Lenses

      Cons:

      None

      Comments:

      This item is a good complement to the 2" ED barlow when watching planets with a 2" crayford focuser. The strong construction allows to mount a digital camera.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    25. Guest

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      Review by astro dj of St. Louis, MO.
      1313884800
      Aug 20, 2011

      5.0 Can't Go Wrong Here

      Pros:

      Compact,Easy to Use,Nice build and feel,Quality Lenses

      Cons:

      Comments:

      I have an early Televue 2.5x barlow I use, and I wanted another less expensive 2.5x barlow for my young sons to use with their scopes (80mm f/5, 130mm f/5). This is a great barlow! We looked at M13 with the 130mm scope, and M57 with 80mm as test objects. Limiting magnitude for the unaided eye was 4.5 due to light pollution.

      A Meade 13.8mm series 4000 eyepiece (early 90's, Japan) with a 68 degree apparent field was used on both objects. With the barlow this provided magnifications of 72x for the 80mm, and 117x for the 130mm scope.

      No image degredation could be detected in either case. Both objects were sharp and clear with pinpoint stars. The barlow did its job of increasing power enough to render a more pleasing size to the objects with out any noticable loss of sharpness at all.

      I would say it performs as well as my old Televue, at less than half the cost.

      Bottom Line: Would you recommend this item? Yes
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      This review was provided courtesy of AgenaAstro.com

    26. Guest

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      Review by hav2tinker of Tennessee.
      1309132800
      Jun 26, 2011

      5.0 Compares to more expensive Barlows!!

      Pros:

      Compact,Accurate,Easy to Use,Does its job well,Excellent multi-coatings,Quality Lenses,Strong Construction

      Cons:

      None period

      Comments:

      I believe you may well come up empty-handed (as I did) trying to catch this Barlow in the act of betraying its presence in the optical train - apparently no matter how good the rest of it may be. My home-built 6", f10.75 Newt uses a 1/21rst-wave primary and a Zygo-tested, 3/4" flat rated at about 1/22 of a wave and, having already rounded up the remaing usual suspects (thermal, stray light control, vibrations, collimation, etc), I was at least prepared to be let down by the GSO stuff. After all, their prices were so low compared to the big boys it almost seemed laughable to expect a lot. But, I still bit because these were the only Barlows I saw on the web that folks were actually raving about. Man, I'm happy I did. These GSO Barlows are for real (also have the 3x ED). But, I find that unless you have downright excellent seeing conditions (and, for me, that means for planetary viewing) you can have some trouble reliably attributing the viewing differences to either all the on-going Barlow-vs-eyepiece comparisons your making or to the variabilities of the seeing conditions. But, before sunset, for me, can be a great time as the seeing typically steadies quite well for some terrestrial viewing of targets of only a half-mile to a mile away. When it's steady enough and at powers of very roughly between 200x to 300x (on my 6"), it's like being there - razor sharp, bright, contrasty views that are better than any photograph. I've compared Tele Vue, Explore Scientific and Brandon eyepieces alone to their longer-focal-length stablemates paired with the GSO Barlows at equivalent magnification. Results were all the same: couldn't tell any difference with my GSO Barlows or without(!)

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    27. Guest

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      Review by MG Noosa of Queensland Australia.
      1308009600
      Jun 13, 2011

      5.0 Double your View

      Pros:

      Accurate,Good price value,Compact,Quality Lenses

      Cons:

      None at this stage

      Comments:

      Great little Barlow used with Vixen SF80 and Celestron C6, very happy, highly recommended, good value for money.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    28. Guest

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      Review by okydoky of Denver,CO.
      1303430400
      Apr 21, 2011

      4.0 I would buy and recommend this product

      Pros:

      Strong Construction,Very well made,Quality Lenses,Compact

      Cons:

      None

      Comments:

      I use this primarily for Astronomy, mainly looking at the Moon with a 10mm and 15mm eyepiece. Barlow is well made and great care has gone into providing a quality product. The views I get while using the barlow are much better than an older barlow...I used to use!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Review by juanirias of Honduras.
      1301961600
      Apr 4, 2011

      5.0 Very nice to have!!

      Pros:

      Strong Construction,Quality Lenses,Compact,Accurate

      Cons:

      Comments:

      I use with my ETX-125, High quality on a budget!!!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    30. Guest

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      Review by Jon of SLC, UT.
      1294272000
      Jan 5, 2011

      5.0 Best barlow for the money.

      Pros:

      Accurate,Compact,Strong Construction,Quality Lenses

      Cons:

      Short Tube

      Comments:

      I bought this in combination with two EWA (UWA) Agena 15mm and 9mm EP. Before I had no barlow and only celestron 25mm and 10mm EP. WOW. The difference is incredible. All the new equipment feels very durable, and well made. It further proves that with how well I am able to see Jupiter (when weather permits ATM). I wish I would have got the set to save some cash, which is nearly the amount of one of the EP's.

      Only thing I've noticed is the shorter tube for the barlow. I tried added two filters on my 9mm EP and I hit bottom before the EP section could go down far enough for the compression ring to hold it properly. Not too big of an issue though. I can always add them to the bottom of the barlow instead.

      Bottom Line: Would you recommend this item? Yes
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      This review was provided courtesy of AgenaAstro.com

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      Review by unitron of Eaton, CO.
      1293408000
      Dec 26, 2010

      5.0 I would buy this product again

      Pros:

      Compact,Quality Lenses,Strong Construction,Accurate

      Cons:

      No cons so far

      Comments:

      Used this product for astro photos and the results equal my Televue

      Bottom Line: Would you recommend this item? Yes
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      This review was provided courtesy of AgenaAstro.com

    32. Guest

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      Review by Bill of Tucson.
      1274572800
      May 22, 2010

      4.0 Sharp barlow

      Pros:

      Strong Construction,Compact,Quality Lenses

      Cons:

      Comments:

      High quality propduct equal to name brand short barlows

      Bottom Line: Would you recommend this item? Yes
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      This review was provided courtesy of AgenaAstro.com

    33. Guest

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      Review by Ken the Lucid of Ontario, Canada.
      1272672000
      Apr 30, 2010

      5.0 Fantastic!

      Pros:

      Compact,Quality Lenses,Accurate,Strong Construction

      Cons:

      None

      Comments:

      This does not have quite the clear aperture of the famous Celestron Apochromatic 2X Barlow, but at 2.5X, it really can't, and I needed that extra 0.5X with my short focal length scope. Truly a great find - you won't be disappointed with this.

      Bottom Line: Would you recommend this item? Yes
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      This review was provided courtesy of AgenaAstro.com

    34. Guest

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      Review by Surya of Milan North Italy.
      1263859200
      Jan 18, 2010

      5.0 Excellent

      Pros:

      Accurate,Compact,Strong Construction,Quality Lenses

      Cons:

      Comments:

      Excellent

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    35. Guest

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      Review by nMAC of Portugal.
      1249603200
      Aug 6, 2009

      5.0 Quality at an affordable price

      Pros:

      Strong Construction,Compact,Accurate,Quality Lenses

      Cons:

      Comments:

      Using for planetary photos and general observing. Built like a tank! Nice looking.

      Bottom Line: Would you recommend this item? Yes
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      This review was provided courtesy of AgenaAstro.com

    36. Guest

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      Review by S. Firestone of Jackson, MS.
      1230940800
      Jan 2, 2009

      5.0 Excellent barlow, inexpensive price.

      Pros:

      Quality Lenses,Accurate,Brass clamping ring,Apochromatic,Fully multi-coated,Strong Construction

      Cons:

      Comments:

      I ordered this GSO barlow lens to replace the dime-store plastic barlow lens that came as part of a telescope kit I obtained elsewhere. When the package from Agena arrived, the product exceeded my expectations. The all metal construction is top notch. The fit and finish on this barlow lens gives you the impression that it would cost at least twice as much as it does. It is far better constructed than a lot of my DSLR camera lenses that cost 3 to 5 times as much. The improvement over the original barlow lens is apparent at first use. The barlow does not significantly impact the visual quality of the eyepieces used. This is in sharp contrast to the original barlow which degraded even my 30mm eyepiece. This barlow removes one poor link in the optical train. One thing I noticed immediately was that this barlow lens appeared to make my plossl eyepieces parafocal. With this barlow attached, I don't need to refocus when changing eyepieces. That was an expected plus. If the quality of this barlow is any indication of the quality of the GSO line of optics and telescope parts, I will definitely be purchasing more from them. Agena Astro products was extremely easy to do business with. I will definitely do business with Agena again.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    37. AstroGuy1

      AstroGuy1 New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Stargazer of Michigan.
      1227052800
      Nov 18, 2008

      5.0 Excellent compact barlow

      Pros:

      Short and Lightweight,Excellent Views,Well machined,Excellent price

      Cons:

      None

      Comments:

      I picked up the GSO 2.5x Apo Barlow because I was unhappy with the performance of "another" brand that I had been using. Granted, the other brand was a bit lower in price but the difference in quality, in my opinion, was well worth the few extra dollars. The GSO Apo is a real bargain.

      The barlow is well machined, short (3" overall), and light weight. Just handling it gives the feeling of a nicely crafted item. The undercut on the lower barrel is "just right". There's nothing that I hate worse (well, almost nothing) than an eyepiece, barlow, or any accessory getting hung up on the undercut because they're cut too deep. I usually end up with the set screw backing all the way out and falling in the grass. Then I'm crawling around in the dark...looking down instead of up!

      The views using the GSO apo barlow are excellent. Nice wide, clear aperture of 23mm and the barlow becomes invisible in use. That is, you don't even know that there's more glass between the eyepiece and the scope.

      I look forward to more clear nights and a chance to enjoy the barlow even more.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    38. Stargazer

      Stargazer New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      1210420680
      May 10, 2008

      5.0 Excellent compact barlow

      Pros:

      Well machined; Short and Lightweight; Excellent views; Excellent price

      Cons:

      None

      Comments:

      I picked up the GSO 2.5x Apo Barlow because I was unhappy with the performance of "another" brand that I had been using. Granted, the other brand was a bit lower in price but the difference in quality, in my opinion, was well worth the few extra dollars. The GSO Apo is a real bargain.

      The barlow is well machined, short (3" overall), and light weight. Just handling it gives the feeling of a nicely crafted item. The undercut on the lower barrel is "just right". There's nothing that I hate worse (well, almost nothing) than an eyepiece, barlow, or any accessory getting hung up on the undercut because they're cut too deep. I usually end up with the set screw backing all the way out and falling in the grass. Then I'm crawling around in the dark...looking down instead of up!

      The views using the GSO apo barlow are excellent. Nice wide, clear aperture of 23mm and the barlow becomes invisible in use. That is, you don't even know that there's more glass between the eyepiece and the scope.

      I look forward to more clear nights and a chance to enjoy the barlow even more.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No
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      Specifications

      Manufacturer GSO