TS Concenter 2'' Adjustment Eyepiece for Newtonian Telescopes

TS Concenter 2" Adjustment Eyepiece for Newtonian Telescopes

  (7 Reviews)
✓ 2 year warranty


Out of stock due 10-15 working days

About this product

Model:  ts_concenter_2z
Part Number:  TSCONCENTER-2Z

TS 2" Concenter - Newtonian Adjustment Tool.

Manufacturers description:

The alternative to all adjustment devices on the market! Here the centre of the secondary mirror is finally perfectly adjusted to the focuser with full illumination (without applying a mark beforehand)! The Newtonian offset is also taken into account. This means that even beginners can achieve perfect adjustment of their Newtonian telescope.

The Concenter eyepiece consists of a closed cylinder, similar to a Cheshire eyepiece. The decisive difference to a Cheshire is the recessed circular disc.

No centre markings on the secondary mirror are required with this product. The adjustment is carried out directly via the edge of the mirror, so that the optical light surfaces match exactly, even taking the offset into account. You adjust much more precisely here than with a laser, above all you can be sure that not only the axis, but also the field are optimally set.

Instructions on how to collimate your Newtonian with the Concenter adjusting eyepiece:

If you hold the adjusting eyepiece in your hand, you will notice a transparent plastic disc with a central hole and concentric engraved circles embedded in the lower end of the telescope. At the other end you will find a central hole, which has been manufactured very small so that the eye has no way of being decentered when looking through it. After inserting the adjustment eyepiece into the focuser, you will see matt translucent rings in front of the optical components of the telescope.

Adjustment of the secondary mirror to the focuser for optimal illumination
This step is done with the main mirror covered. When using the Concenter eyepiece, care must be taken to ensure good illumination. The secondary mirror, assuming the focuser is installed at right angles, can now be adjusted in such a way that it is positioned by moving or rotating it so that it appears circular and without offset between the circles of the adjustment set. With the focus regulator of the focuser you can bring the outer edge of the secondary mirror and the matching circle to cover. Even minor deviations from the ideal position are recognised here immediately. In this way, you can bring the secondary mirror into the optimal position for pull-out, down to the millimeter. This step is only necessary once, after which you can remove the cover of the main mirror.

Aligning the secondary mirror to the main mirror
Look through the small opening of the concentrator and adjust the secondary mirror with the adjusting screws until the bright reflection of the main mirror is concentric with the circles.

Alignment of the main mirror on the optical axis
Now bring the centre marking of the main mirror through the adjustment screws on the main mirror cell exactly in the middle of the concentric circles. You will immediately see the finest deviations. Your Newtonian telescope is then perfectly adjusted.


Customer reviews

Average Rating (7 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Good but flawed concept
21 February 2024  | 

The instructions say to cover the primary mirror, there is zero chance of me getting my hand behind the spider of a 130PDs without removing the spider, therefore defeating the purpose. I tried shoving a sponge through, which worked but smeared the secondary and covered the primary in sponge dust so I had to remove them both to clean them. Sure it would be great on larger OTAs.

Rating (max 5):  
Great collimation without a laser.
30 November 2023  | 

No need for a laser that also needs collimating. Used this with my new 2 inch compression ring and it was easy to get spot on collimation. I was able to verify by de-focusing a bright star. Very quick and simple with great results.

Rating (max 5):  
A mandatory tool for collimation
20 June 2023  | 

It really helps with the alignment of the secondary mirror, it makes the process easier, faster and more accurate. Definitely needed for the complete collimation of a reflector telescope.
It is a little expensive and you will also need a Cheshire to align the primary mirror but this is a very useful and recommended tool to have.
As always, FLO service is magnificent!!

Rating (max 5):  
2Ē concenter
27 January 2023  | 

I find this invaluable in setting up my secondary mirror especially after removal from the spider. Allows you to get your secondary mirror perfectly positioned in all axis of its movement. Definitely a very vital part of of my collimation devices. Fast delivery as expected from FLO.

Rating (max 5):  
Secondary mirror placement
24 November 2022  | 

Great for lining up the secondary mirror to the focuser

Rating (max 5):  
Concentre collimating
08 December 2021  | 

Iíve had a concentre 2Ē eyepiece for a year now having purchased before Flo stocked this item , Step 1 before you even touch the secondary, place the concentre into eyepiece holder , now using a long ruler line the ruler with the spider vane in line with the focuser, the concentre barrel needs to be parallel with ruler edge if it isnít then your focuser isnít aligned 90 degrees to your Ota , shim if required under the focuser to realign ,failing to check this and correct as required you will not be able to align your secondary properly as the secondary will not look aligned whilst looking through concentre, now block the primary and using the concentre collimate the secondary so it is centralised to the circles on the concentre, please note mass produced scopes like my 200pds may need fettling as my focuser wasnít actually aligned centre of the secondary mirror or 90 degrees to Ota (upgraded to a Steel track solved this due to it design)so you may need to elongate holes to suit but once you have checked this process then collimating becomes easier knowing the secondary mirror is setup correctly, now you can collimate your primary, I still use a Cheshire/laser /colli cap to feed my collimating ocd on the primary but the concentre will without error tell you if secondary is aligned, expensive for what it is But it is worth it and I would recommend.

Rating (max 5):  
Vital Simple Tool for Collimation
23 April 2021  | 

I have been using the 2" TS Concenter for a number of years now, much before FLO had them in stock. I use this predominately as a 2" sight tube to collimate my secondary mirror on my 130PDS.
Two items I would recommend for collimation the 2" Concenter eyepiece and good chesire eyepiece to collimate the primary. Forget expensive lasers.


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