Celestron Cheshire Collimation Eyepiece for Reflector & SCT Telescopes | Cheshire Alignment Tool, Precise Newtonian & SCT Collimation/Alignment, Improves Optical Performance, Fits 1.25" Focusers

Maybe this is not recommended to collimate a RC telescope, but it worked for me and with the simple design there is nothing needed to check the accuracy of this eyepiece.

Very well made. I bought this to have one more way to collimate our telescope. I tested collimation with the ring around a star and with the cheshire and had the same results.

If you have a Newtonian or Dobsonian telescope, you can purchase all manner of complex thingy me do's to align your primary and secondary mirrors, (many of which often work poorly) or you can just buy this combo tool for a great deal less. This eyepiece is a both a sight tube and a Cheshire eyepiece rolled into one. You then simply align your secondary mirror under the sight tube and then align the crosshairs reflection on the primary with the crosshairs at the bottom of the sight tube and bang, you are done. If you have never done a collimation before it might take up to ten minutes the first go, but after that, it takes less than two minutes. Absolutely essential tool that just flat out works. Five stars.

I purchased this to help with the collimation of a few telescopes I have, thought it would improve the process. Was hoping to be able to take this out of the package and with a few directions it would be a simple task. Unfortunately the directions were a little hard to follow for the first timer that I felt like I was. After finding some internet help, I was able to Collimate my scopes and the tool does make it a simple process. I shared this with some of my friends who have experience in this. They found the eyepiece to be very helpful. If you know what you are doing it is out of the box great, if you are a novice like myself it takes a little playing. While I ultimately managed to complete the process, it was a little frustrating at first. If you are planning on transporting your scope regularly, I would recommend this tool. When finally completed, it did a great job.

Using this collimator to align the mirrors in a reflector scope is a must-have item. After the procedure, images are crisp and clear across the field of view, even with my relatively small (3" F9) Celstron reflector. Frankly the instructions for me especially as a first time user are not easily understood, especially in discerning between various images seen through the eyepiece. I researched "collimation" on the web, and pieced together sufficient info to understand all the images fairly well. Also placed a small, stick-on center dot on the main mirror for convenience during alignment. Definitely recommend this eyepiece - quality built for the money - it will be used periodically to keep the scope in tune, and it can be used as one graduates to larger reflector scopes. I never tried a laser collimator, but with the excellent results from this piece, not sure that a laser is necessary, at least with an F9 scope - perhaps it might make a difference on an F5 or lower, just guessing.

Just fairly disappointed with the level of play of this tool - inside Orion XT8 Crayford (2 in. with 1.25 inch adapter in place) focuser... Still decided to keep it (and will remedy the issue myself, by some sort of all-round shimming for a tight fit) since I guess at this price range they are all pretty much the same, just branded differently. The overall quality of the build is OK. I got mine real cheap from amazon warehouse deals, and it just came in less than adequate packaging. On the initial use, I was just surprised to see that my initial collimation (done with just the cap that came with the scope) was pretty much spot on, so cannot really comment about the ease of use for this device. Clear skies to all! Edit: just wrapped a piece of "stick it" paper note (sticky area goes across the length of tube, vertically; make sure there is no overlap - cut it so there is a few mm gap between the glued beginning and the end of paper), and it fits very snug and perfect iside 1.25 in. adapter. Made my colimation spot on!

THANKS GREAT ITEM

Can't live without this tool now. Followed the steps recommended by other Amazon reviewers on how to do collimation. 1st, you've got to adjust the secondary mirror, per instructions. I recommend viewing several YOUTUBE videos on collimation to get an idea. 2nd, adjust the big rear mirror and line up the crosshairs. Good to go afterwards. My 114mm Newtonian reflector takes only a few minutes to adjust, once I got the hang of it. EXCELLENT viewing results every time. Have been tracking the planets, Andromeda galaxy, and star clusters all summer and fall. Happy star gazing to all.

Quality is good. The wires that form the X on mine were about a 1mm off center, but you can try bending, although im hesitant to do so, afraid of breaking them off. But most importantly, it does what supposed is supposed to do, which is to center the secondary in the focuser, collimate the tilt of secondary and primary. If this is your first collimation device, then this is what you need. Dont buy a laser first, youll mess up more than fix your accuracy.

Perfetto per collimare tutte le parti del telescopio riflettore: focheggiatore, specchio secondario, specchio primario. Naturalmente occorre saperlo utilizzare a dovere, ma una volta presa confidenza con esso, è veramente preciso. La collimazione dello specchio primario, la più frequente, è un attimo.

Muchas Gracias, llego en excelentes condiciones y en el tiempo estimado. Le quedo perfecto al telescopio Celestron 76EQ, al principio fue complicado collimar ya que es el collimation es el básico(sin láser) pero con unos cuantos tutoriales ya le vas entendiendo, pero si buscas comodidad, es mejor el laser

Made from quality materials does exactly as a state recalibrates the eye peace

Après avoir réalisé la colimation sur tube newton le résultat est parfait. Environ 30 minutes pour un réglage optimal. Beaucoup plus efficace qu'un colimateur lazer.