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Blue Fireball 1.25" Eyepiece Extension Tube with 1" Extension # X-01

5.0 (25 Reviews) Read Reviews Write Review
Brand Blue Fireball
Part Number X-01
Availability available

Product Info

Manufacturer Description

Description/Uses:

  • Adds 25.4mm (1") of back-focus travel to your telescope focuser *
  • Fits standard 1.25" eyepiece tubes in telescopes and accessories like diagonals
  • With this, eyepieces and accessories that you may not have been able to use because your telescope tube was too short are usable again

Features:

  • Precision machined from aluminum and black anodized
  • Threaded to accept standard 1.25" astronomy filters
  • Features a brass compression ring so the inserted accessory will not be scratched or dented by the locking thumbscrew

Specifications:

  • Total Length = 1.98" (50.4mm)
  • Outside Length of Upper 1.25" Barrel = 1" (25.4mm)
  • Inside Length of Upper 1.25" Barrel = 0.92" (23.4mm) *
  • Length of Lower 1.25" Barrel = 0.91" (23mm)
  • Maximum Outer Diameter (Excluding Thumbscrew) = 1.5" (38mm)
  • Thread Specification (Telescope End) = M28.5x0.6 Female
  • Thread Specification (Thumbscrew) = M4x0.7 Male
  • Weight = 1.2oz (34g)

Additional Information:

* If the inserted eyepiece does not fully slide into the upper 1.25" barrel, additional in-focus travel will be required by the amount the eyepiece extends out

Reviews

5.0 (Based on 25 Reviews) 96% of reviewers recommended this product.
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    1. Bigfoot

      Bigfoot New Member

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      Review by Robert Z.
      1537870596
      Sep 25, 2018

      5.0 Satisfied my need

      Pros:

      Cons:

      Comments:

      As with the other Fireball extension tubes that I ordered, this one did its job perfectly. Looks good, I like the large tightening screw knob.

      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 Dave A.
      1520981225
      Mar 13, 2018

      5.0 Solid extension

      Pros:

      Cons:

      Comments:

      Bought the 1", 1.5" and 2" extension tubes to use with a 102mm refractor. All work amazingly.

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

      This review was provided courtesy of AgenaAstro.com

    3. Guest

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      Review by David F.
      1516492000
      Jan 20, 2018

      5.0 1 1/4" Extension

      Pros:

      Cons:

      Comments:

      Very high quality product and the usual expert service from Agena Astro!

      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 JOSEPH D.
      1512010918
      Nov 29, 2017

      5.0 Excellent in all respects. Good price.

      Pros:

      Cons:

      Comments:

      The Blue Technologies 1.25", 1" extension tube is excellent. It is machined to exacting standards and the eyepiece ring holds all eyepieces firmly without marring the metal. The price is right and it surely does the job intended.

      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 MARK S.
      1511576316
      Nov 24, 2017

      5.0 Extensions are great.

      Pros:

      Cons:

      Comments:

      I have upgraded two of my telescopes with new focusers and 1" extensions are just the thing to optimize the new travel positions. I commonly extend the focus point further outside the tube to enable more accessory function.

      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 SG-0029-8810 C.
      1509098003
      Oct 27, 2017

      5.0 Blue Fireball 1.25" Eyepiece Extension Tube

      Pros:

      Cons:

      Comments:

      The 1.25" filter thread in the extension tube allows me to have the Baader Solar Continuum Filter and Baader UV/IR Cut / L-Filter cascaded together before the diagonal for solar imaging.

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

      This review was provided courtesy of AgenaAstro.com

    7. Guest

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      Review by Robert F.
      1504293490
      Sep 1, 2017

      5.0 Eyepiece tube extension

      Pros:

      Cons:

      Comments:

      My new Blue Fireballs tube extension is perfect. The knurled knob to tighten the eyepiece in place in near the end, which my old one is not. It also is nicely blackened inside and threaded for filters, which my old one is not. Looking forward to using it.

      I would like to commend Agena again for their super fast delivery.

      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 George T.
      1493550343
      Apr 30, 2017

      5.0 Just what I needed!

      Pros:

      Cons:

      Comments:

      Alows me to use my homemade astronomical telescope for closer, terrestrial viewing. The tightening mechanism works wonderfully- dont know why all focusers arent made that way!

      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 scott b.
      1492341401
      Apr 16, 2017

      5.0 high quality good price

      Pros:

      Cons:

      Comments:

      I like the Blue Fireball products, I have a few of their extensions and they are well machined, have brass compression rings and are a good price.

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

      This review was provided courtesy of AgenaAstro.com

    10. Guest

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      Review by Mrray of Miami, FL.
      1443398400
      Sep 27, 2015

      5.0 Excellent adapter.

      Pros:

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

      Cons:

      Comments:

      Great adapter. Just the right size to fit those lengths that are in between.

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

      This review was provided courtesy of AgenaAstro.com

    11. Guest

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      Review by Uwe of Germany.
      1438992000
      Aug 7, 2015

      5.0 Works perfectly for my purpose

      Pros:

      Compact,Accurate

      Cons:

      Comments:

      My intended purpose for this product is actually sort of off-label. I do not use this extension tube to extend the back-focus travel of a telescope. Instead, I use it to keep two filters (a Solar Continuum and a Pol filter) permanently mounted within the eyepiece barrel of a Herschel wedge. Thus, I don't have to screw the filters off and on every time I change the eyepiece. Loosening the screw of the wedge's eyepiece barrel also allows to rotate the extension tube within the barrel, to change brightness via orientation of pol filter. And the tube is short enough so that the added back-focus travel is no problem for my telescope.

      Overall rating: Works perfectly for this purpose.

      Also, reasonable shipping costs and very fast delivery for overseas ordering (from the US to Germany in my case).

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

      This review was provided courtesy of AgenaAstro.com

    12. Guest

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      Review by flyndr of Christchurch, New Zealand.
      1424736000
      Feb 23, 2015

      5.0 I recommend this product

      Pros:

      Lightweight,Easy to Use

      Cons:

      Comments:

      This extension tube has a brass strip inside so the position of the eyepiece/camera can be adjusted and clamped without screw marks on the inserted barrel. This allows adjustment of the degree of extension so some extent.

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

      This review was provided courtesy of AgenaAstro.com

    13. Guest

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      Review by miket883 of Upstate New York.
      1424476800
      Feb 20, 2015

      5.0 Great quality at a reasonable price!

      Pros:

      No

      Cons:

      No

      Comments:

      I needed an extender for my eyepieces to reach focus and this did the trick. Quality construction and design uses compression/thumbscrew to securely hold eyepiece without leaving a mark.

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

      This review was provided courtesy of AgenaAstro.com

    14. Guest

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      Review by spinner of Fremont, CA.
      1390780800
      Jan 26, 2014

      4.0 Converts a guide scope to finder scope

      Pros:

      Easy to Use

      Cons:

      Comments:

      I used this on a 50mm guide scope designed for guiding and with this extender, I was able to achieve focus when an eyepiece is placed.

      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 Green Zebra Observatory of North Central Maryland.
      1390694400
      Jan 25, 2014

      5.0 Solid construction

      Pros:

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

      Cons:

      Comments:

      Used with a flip mirror system to allow eyepiece to come to focus at the same time as the camera.

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

      This review was provided courtesy of AgenaAstro.com

    16. Guest

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      Review by JimBr SFAAA of Miami, FL.
      1385769600
      Nov 29, 2013

      5.0 Works great with my 5" SCT

      Pros:

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

      Cons:

      Comments:

      I leave this attached to my 5" Celestron Nexstar SE as the brass compression ring protects eyepiece or diagonal from setscrew scratches.

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

      This review was provided courtesy of AgenaAstro.com

    17. BigZ

      BigZ New Member

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      Review by Stargeezer of Nottingham, NH.
      1370304000
      Jun 3, 2013

      5.0 A perfect solution to a problem

      Pros:

      Accurate,Lightweight,Strong Construction

      Cons:

      Comments:

      This extension tube was needed because I made an innocent error in calculating the position of the focal plane when I was designing my Newtonian reflector. It was easier to add an inch of back focus with the extension tube than to reposition either mirror. This extension tube is nicely finished, and it adds hardly any weight to my rig.

      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 Chuck Hunt of Brook Park, Ohio.
      1360368000
      Feb 8, 2013

      5.0 Extension Tube

      Pros:

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

      Cons:

      Comments:

      I bought this to upgrade an old extension tube adapter that didn't have a compression ring.
      The adapter is threaded for standard astro filters.
      I use this adapter on my eyepieces (Brandons) that don't have a standard filter screw thread. Screw a regular filter on the adapter then insert the eyepiece for use. You can also use this adapter if you need more out focus distance on your telscope.

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

      This review was provided courtesy of AgenaAstro.com

    19. Guest

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      Review by geo. of Petaluma, CA.
      1349481600
      Oct 5, 2012

      5.0 Converts a TV 2x barlow to 2.4X

      Pros:

      Lightweight,Compact,Easy to Use,Strong Construction

      Cons:

      Comments:

      Nicely finished, nicely machined product--this is the second blue fireball accessory I've bought. I got the 1" extension in order to use my televue 2x (1.25") barlow as a 2.4X barlow, and it seems to do the trick. Many televue 1.25" eyepieces require out-focus compared to other lines (such as Pentax XWs, various orthos, etc.); the TV 2x barlow is parfocal with TV eyepieces, and so also requires out-focus when used with non-TV eyepieces--but that means the additional in-travel required by this extension winds up bringing those eyepieces pretty close to their native focal position, making it an ideal way to get two great barlows out of one.

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

      This review was provided courtesy of AgenaAstro.com

    20. Rguasto

      Rguasto New Member

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      Review by rguasto of New York.
      1341014400
      Jun 29, 2012

      5.0 Very nice product

      Pros:

      Strong Construction

      Cons:

      Comments:

      Purchased the extension for my ES 68* 24mm eyepiece. The barrel of the eyepiece was machined undersized and could fall out of my slip-fit vintage focuser. The eyepiece just comes to focus and is securely held in the focuser.

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

      This review was provided courtesy of AgenaAstro.com

    21. Guest

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      Review by Moto Bob of Columbus Ohio.
      1335744000
      Apr 29, 2012

      5.0 Does What I Needed It To Do

      Pros:

      Easy to Use

      Cons:

      Comments:

      Well constructed, good price point.

      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 Gquinzi of Voorhees NJ.
      1319846400
      Oct 28, 2011

      5.0 Quality product and free shipping!

      Pros:

      Lightweight,Strong Construction,Compact

      Cons:

      Comments:

      I love the Blue fireball line of accessories. The extension I ordered is well made, lightweight and has a snug fit in the focus tube. It also features a compression ring to ensure eyepiece and accessory barrels are not marred as would if using extensions with setscrews. Another plus was free shipping which you don't find often.

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

      This review was provided courtesy of AgenaAstro.com

    23. Guest

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      Review by Astronomy Junkie of Kalamazoo, MI.
      1292803200
      Dec 19, 2010

      5.0 "A must for any Newtonian Telescope"

      Pros:

      Great value for the price,Strong Construction,Easy to use,Compact

      Cons:

      None

      Comments:

      Perfect for anyone who is serious about Amateur Astronomy. It is great for Newtonian telescope owners who need extra back-focus, especially in Astrophotography! Highly recommended!

      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 Lannding of Granite City, Illinois.
      1265932800
      Feb 11, 2010

      5.0 It looks and works exactly as advertised

      Pros:

      Quality Lenses,Accurate,Compact,Strong Construction

      Cons:

      NO CONS

      Comments:

      A very versital piece of equipment. The compression ring holder centers the eyepiece and doesn't damage expensive eyepieces.

      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 FastJack of Wenham, MA.
      1243382400
      May 26, 2009

      5.0 Eyepiece extension tube by Blue Fireball

      Pros:

      Strong Construction,Accurate

      Cons:

      Comments:

      Very nice clamping ring- works very well and is nicely machined.
      Cheers,
      -J

      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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