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Agena 1.25" Cheshire Collimating Eyepiece for Refractors

4.8 (22 Reviews) Read Reviews Write Review
Brand Agena AstroProducts
Part Number -
Availability available

Product Info

Manufacturer Description

Is collimating your refractor a real chore? Collimating your refractor is quick and easy when you use this 1.25" Cheshire collimating eyepiece.

To use this eyepiece, simply cap the telescope, remove the diagonal, and place the eyepiece directly in the focuser. Use natural daylight or shine a flashlight into the side opening with the 45-deg angled silver plate. Look into the small opening at the top of the eyepiece. You will see one or more small faint circles (usually overlapping) near the center. Adjust the objective cell's push-pull bolts until the small circles merge into one. Thats it! With precise collimation, your refractor telescope will deliver the best image it can.

No additional instructions are included with this product, but you can easily find additional information about Cheshire eyepieces and their use on the internet. The dual images can sometimes be hard to see (especially in very bright or very faint light) but you will see them. As with most other telescope collimation/alignment procedures, use of this accessory requires patience and experience.

This Cheshire eyepiece fits in 1.25" focusers or in 2"-1.25" adapters. Weight = 2.8oz.

Please also note the following:

  • Use of this item assumes that your focuser is aligned properly with your telescope tube.
  • This item can only be used if your refractor telescope cell has a push-pull or other mechanism to adjust the lens elements. It will be of no use with fixed cell objectives that cannot be adjusted. 
  • You may notice a small dimple on the angled silver plate. This is a manufacturing artifact and not a defect. This will have no impact on its performance.

Reviews

4.8 (Based on 22 Reviews) 100% of reviewers recommended this product.
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    1. Guest

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      Review by David H.
      1549923915
      Feb 11, 2019

      5.0 Works well

      Pros:

      Cons:

      Comments:

      Worked well for my refractor. Unscrew the crosshairs and the lens reflections are easy to see.

      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 Michael L.
      1544895693
      Dec 15, 2018

      5.0 refractor colimation eypiece

      Pros:

      Cons:

      Comments:

      Very good. Works as described.

      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 harold h.
      1532399232
      Jul 23, 2018

      5.0 great tool

      Pros:

      Cons:

      Comments:

      I was able to use this eyepiece to align a focuser that was out of alignment.
      I thought I had to collimate the lenses but this eyepiece saved me the extra effort.

      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 Francesco M.
      1528869291
      Jun 12, 2018

      5.0 Works very well, the reflection

      Pros:

      Cons:

      Comments:

      Works very well, the reflection is clear and well centered. I found that the crosshairs do get in the way, but they're very easy to remove by unscrewing the ring that carries them.

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

      This review was provided courtesy of AgenaAstro.com

    5. Dr. Ski

      Dr. Ski Well-Known Member

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      Review by Dr. Ski of Obscure Philippine Island.
      1443225600
      Sep 25, 2015

      5.0 Slick!

      Pros:

      Accurate

      Cons:

      Comments:

      They say that the focuser needs to be properly aligned to the optical tube, but I found this not to be the case. I used this on my ES 102 Achro and had no problem aligning the circles by adjusting the push/pull bolts on the objective lens. The aligned image was slightly off-centre in the crosshairs of the eyepiece so I loosened and tightened the 3 screws which attach the focuser to the tube until the circle was centered with the cross-hairs. CA was greatly mitigated! I no longer need to use my #11 filter to remove purple fringing at high x. What a great gadget!

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

      This review was provided courtesy of AgenaAstro.com

    6. rmscott59

      rmscott59 New Member

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      Review by RMS of NorCal.
      1414886400
      Nov 1, 2014

      5.0 Simple, effective!

      Pros:

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

      Cons:

      Comments:

      If you own a refractor and want to squeeze every drop of performance out of it, you need this product to ensure it's collimated precisely! Improved the views in my 120mm and 150mm refractors!

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

      This review was provided courtesy of AgenaAstro.com

    7. Paul Schofield

      Paul Schofield New Member

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      Review by Paul of North Carolina.
      1402358400
      Jun 9, 2014

      5.0 Worked fine

      Pros:

      Strong Construction,Accurate,Lightweight,Easy to Use

      Cons:

      Comments:

      I was able to check the collimation and correct the focuser alignment on both my refractors. It was easy to use and the instructions were given right on Agena's website. Thanks again Agena Astroproducts.

      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 gunfighter48 of Mill Creek, WA.
      1397001600
      Apr 8, 2014

      5.0 Cheshire Collimation Eyepiece and ES AR1

      Pros:

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

      Cons:

      See Review

      Comments:

      I bought a ES AR152 6" refractor about a month ago. When I got it one of the push screws in the lens cell had fallen out inside the dew shield.

      I bought the Agena Cheshire Collimation Eyepiece to check and make sure that it was still collimated. I tried it but was having a hard time seeing the donut becuase of the crosshairs in the eyepiece. I found a post on the internet that said just unscrew the crosshair piece and it would work much better. I did and it does.

      I have no trouble seeing the donut now. When I put the screw back in inially I tightened it down to the same level as the other two push screws. I found that I had to back out the screw I put in by about a 1/32 turn. Took a look and it was perfect.

      Saved me from buying another Cheshire with out the crosshairs. It works great now.

      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 Phil Barker of Hokitika New Zealand.
      1390608000
      Jan 24, 2014

      5.0 Agena Cheshire refractor Collimator

      Pros:

      Easy to Use

      Cons:

      Comments:

      Well made, easy to use, really useful

      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 LSMFT of Desert USA.
      1381104000
      Oct 6, 2013

      5.0 Easy as.. pie!

      Pros:

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

      Cons:

      Comments:

      Although I'm a 'casual-recreational' astronomer - I've been at this hobby for a long time and have quite a collection of scopes, so I bought this to check out my refractors. It is very easy to use and quickly shows how well collimated your telescope is.

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

      This review was provided courtesy of AgenaAstro.com

    11. Guest

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      Review by Grif of North Carolina.
      1375056000
      Jul 28, 2013

      5.0 Very easy to use

      Pros:

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

      Cons:

      Comments:

      This is easy to use, can collimate my refractor in the daytime. Just cover the objective, put the collimation eyepiece in the drawtube, and fix a light source to shine into the side hole, I used a flashlight. I adjusted the cell a small amount until the two circles were inside each other. A very useful piece of equipment, and for the low price, is an exceptional value.
      Billy

      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 Matty of Melbourne.
      1366329600
      Apr 18, 2013

      5.0 Easy as...

      Pros:

      Accurate,Compact

      Cons:

      Comments:

      So easy to use. I knew from star tests that my optics were in great alignment and this proved it. According to a laser collimator I have the optics are out of alignment...yes sometimes can't beat the old methods.

      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 Oz of Hopkinsville, KY.
      1363996800
      Mar 22, 2013

      5.0 Refractor must have

      Pros:

      Compact,Accurate,Easy to Use,Strong Construction

      Cons:

      Comments:

      If you own a refractor buy this eyepiece. It works just as described. Easy to check your collimation, just slip the eyepiece in with the objective lens covered and the paterns are obvious. I was able to improve the collimation on a 80mm refractor without a collimatable lens cell at the focuser. Not as easy to do but it worked well all because of this great little collimation tool. Its real easy if your lens cell is adjustable. Any refractor can benifit from this eyepiece.

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

      This review was provided courtesy of AgenaAstro.com

    14. spongebob

      spongebob New Member

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      Review by Spongebob of New Jersey.
      1354320000
      Nov 30, 2012

      4.0 Easy as a first check.....

      Pros:

      Compact,Easy to Use,Lightweight

      Cons:

      Comments:

      Once you realize how to use it, its a good beginning to test your refractor. You can see a very small concentric ring, but there after you should do a star test for best results. It's very light and inexpensively built.

      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 MawkHawk of Detroit, MI.
      1348358400
      Sep 22, 2012

      4.0 Agena 1.25" Collimating Eyepiece for Refractors

      Pros:

      Lightweight,Easy to Use,Accurate

      Cons:

      Difficult To Focus

      Comments:

      I have been told many times that it is very difficult, if not nearly impossible, to collimate a refractor and that I should not even try. That is until someone told me about this product. It is an inexpensive and pretty easy way to collimate. I needed an easy way to collimate after cleaning my filthy lense and this product allowed me to do that. I didn't give it 5 stars because I can't get the crosshairs to focus well. Not sure if it is just mine or an issue with the product. But all in all it made a huge difference on my scope.

      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 Max Headroom of Vail, AZ.
      1348358400
      Sep 22, 2012

      4.0 Useful tool

      Pros:

      Lightweight,Easy to Use,Compact

      Cons:

      Comments:

      I have used this to check collimation on 4 refractors, with results that correlate with the image quality in each. It helps in making adjustments. Make sure the reflective part is square with the hole in the side. It can move if the top gets loose, but it's easy to fix.

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

      This review was provided courtesy of AgenaAstro.com

    17. Guest

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      Review by Greg of Upstate, NY.
      1330128000
      Feb 24, 2012

      4.0 Works well

      Pros:

      Cons:

      Comments:

      This product works well for collimating a refractor. The reflective surface could be larger to add more light for collimating.

      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 voyager of Japan.
      1320624000
      Nov 6, 2011

      5.0 Simple to use

      Pros:

      Easy to Use

      Cons:

      Comments:

      It's useful. And works well with my 5" Refractors.

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

      This review was provided courtesy of AgenaAstro.com

    19. dvoprvb

      dvoprvb New Member

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      Review by dvoprvb of Plainville, CT.
      1313107200
      Aug 11, 2011

      5.0 Hey! Give it a try

      Pros:

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

      Cons:

      Comments:

      Easy to use. If you have push pull collimation on a refractor this is the item for you!

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

      This review was provided courtesy of AgenaAstro.com

    20. Guest

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      Review by eyeball of Australia.
      1306627200
      May 28, 2011

      5.0 Simple Fast and Accurate Collimation

      Pros:

      Simple,Quality Lenses,Accurate,Compact,Use by Beginner,Strong Construction

      Cons:

      None

      Comments:

      After hours of frustration, couldn't collimate an 8 inch Reflector using a "popular" laser collimator...better results came from setting up by "eye"...tried this collimator (bought to collimate a Refractor!) Simple, easy, did the job in 5 mins...very easy when you know how.... AND have a good Collimator.
      Thanks Agena Astro....a very happy customer.

      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 Larry of Texas.
      1306627200
      May 28, 2011

      5.0 Razor sharp alignment tool

      Pros:

      Easy to store,Day time use,Strong Construction,Accurate,Simple to use,Compact

      Cons:

      None

      Comments:

      This works great on Refractors that allow collimation and fits easily in a standard eyepiece holder.

      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 CN user of Wisconsin.
      1294012800
      Jan 2, 2011

      5.0 Agena 1.25" Collimating Eyepiece for Refractors

      Pros:

      Accurate,Compact,Quality Lenses

      Cons:

      Comments:

      Worked well with my 2 classic refractors.

      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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