Collimation Made Easy Understanding Collimation 

I collimated my 8” Dobsonian with a Cheshire and collimation cap. My friend had a super expensive laser (Howie Glatter) and brought it to mine to check my collimation for me. He was shocked at how precise it was and accused me of using a laser. The Cheshire and cap are the way to go

No need to apologize. Your videos are great.

I have a Newtonian Telescope since more than 1 year and only now I understood collimation and checked mine 😃. Good news is that after many hours outside and travels all over the country the factory collimation still holds perfectly! Thank you very much Jason for the detailed explanation.

I put off collimating my scope thinking that I was going to misalign the optics beyond the point of no return. I just said to myself that "well, I'll mess with this on a day that I knew there was not going to be any clear skies soon", so I just got out the Allen wrench and started turning screws to see what would happen. Not the insurmountable task I thought it was going to be. Practice will make process faster in the field. Your videos are very helpful, Jason, thanks!

Thanks Jason. I have a 5 inch Newtonian and Meade didn't provide a collimation cap. But I followed you through and that's it. Got it through to your second category though, the good collimation. 😅😅

If collimation is a huge thing that is required, youd think that all primary mirrors would be manufactured with a "cetre spot" built into the centre of the primary mirror

Dude, as an enthusiastic noob to astronomy, I love your passion and your generosity in sharing your knowledge on the subject. Thank you so much.

Thanks Jason, amazingly helpful videos mate. Recently got myself a 6" Newtonian, and I have learnt more from your channel than anywhere else. Made my collimation cap and haven't looked back. I would strongly recommend this channel for anyone starting out.

What is your recommendation on installing a upgrade collimation kit from High Point Scientific? The kit includes, 3 secondary collimation "knobs", flocking paper and 3 primary collimation "springs". Is it worth the extra $$? Thanks.

Rather odd tech question about collimation... I have to smaller Newronians, (76x700mm and 114x900mm) both modified by me for use with a dslr with an attached t-ring adapter. My question is, since both are used ONLY for astrophotography, would it be ok to collimate them with the dslr in place using the screen on the camera rather than visually checking down the focuser tube?

Out of all the thousands of you tube videos about telescopes I always enjoy watching yours the most. Even when it is about something I am quite proficient at...lol...thank you I appreciate everything you do for our hobby

Jason, my primary mirror screws are Phillips. Can I switch them out for finger screws? Correct me if I'm wrong, lol. Wouldn't it be easier and more precise with finger screws than Phillips head screws?

How do you get the star exactly in the centre of the primary mirror. Also I have a Sky-Watcher SkyMax-127 which has the eyepiece in the middle of the bottom of the scope. Any idea how to remove this bottom end to get to the mirror?

Hi, I've managed to make a collimation cap and have all 3 clips visible, but there are two other circles (the secondary and the focuser) that are off center, it also seems like no matter what I do, they will not move, do I need them to be centered or is that normal?

Thank you for both parts of this 'tutorial'. I was considering getting rid of my Newtonian for a different style so I didn't need to collimate. I am now more prepared to attempt any collimation if required. Keep up the good information. PS I have subscribed to your channel because of these videos.😀

Hi Jason. I’ve followed all your instructions and have a perfect view but!! The cross hairs are off center . Perfect in the center view with the symmetry in the eye. But it bugs the heck out of me that the cross hair thing. Solutions? Thanks

You know why all of use noobs obsess over collimation? Because every time we ask about a problem that we are experiencing in a public forum, at some point someone will ask about our collimation. And we often don’t have the experience to confidently say that our collimation is good to go. But I keep learning by watching videos like yours so that I can have a more balanced approach to the process. After all, I’m not building a scope from scratching. I’m massaging a bone stock 8”/F5.9 Dobsonian. Pretty common. And pretty easy.

My clumsy self let go of my new telescope so that the front part of the “pipe” impacted my window, and now I see a reflection of the inner surface of the “pipe” when I look down the eye piece, I assume it’s not collimated anymore. This was my first scope and already it seems that I messed up. I will try this method, wish me luck :(

Hi there, I've a question if you can please answer?. I need to do some work on my secondary mirror as the central screw to be able to rotate the secondary has rounded. When I put it back in I need to make sure it's correctly positioned through the viewer. However, in your video you've basically just looked down the viewer without any lens or collimating tools in it. I thought you had to use a tool? Generally very useful video and I've taken some key points from it. I'm just concerned I won't get the secondary positioned correctly to catch all the light and angled correctly to the viewer

I'm a beginner and I don't even have a telescope to start this hobby. 😊 but I'm glad I found this channel where I can learn a lot of basic things before deciding to get my first telescope. thank you very much 🙏🙏🙏

Collimation is not easy. For this RU-vid video: You really need to have a video camera in the focuser and then adjust each of the screws and show what happens to the person watching. The spider hub has a central screw which can do rotation - 3 screws for tilt and the primary mirror has 3 screws too. It's easier to use a properly aligned laser. At worst case you can rotate the hub so that the view looks reasonable but a laser put in the focuser can go down to the primary mirror and not even hit the secondary mirror upon returning - then you are in a lot of trouble. These sort of RU-vid videos are only good when the telescope is already close to a good collimation and the 2 offsets were set up correctly in the factory. One offset is towards the primary and the other is away from the focuser.

0:00 Theory of collimating 13:27 Secondary Mirror (top) 18:45 Primary mirror break down 26:27 How to use culmination cap

Is it possible for the secondary mirror to be out of line with the focal tube? For example someone backs the three adjusting screws all the way out then tightens the middle screw until it is just almost butted up against the mount then uses the 3 adjusting screws to collimate will it throw everything out of wack?

Some center screws on the secondary are not supposed to be loosened, refer to the instructions that came with your telescope to be sure. A star or dot is fine for marking the center of the primary, but will not work with a laser collimator, a donut shaped sticker is required for that. To avoid the possibility of damaging anything, have the tube of the scope as well as the focuser oriented horizontally.

Again a good series on the subject but it still does not answer my question on how we know a cap barrel is any less a skew then the laser barrel? They both fit in the same barrel holder. Somehow it's assumed the cap is a perfect fit, that is the missing piece that I would like to know more about.

Hello I have a tasco reflector telescope I am getting close to using the telescope i think but when I look through the eyepiece all I see is black. I don’t know if it’s because I’m putting on the eye peice wrong or does it have to do with primary mirror. I remember i tightened the screws really tight too

My spider have only three branch, how is that possible ? I can't see the whole square un first mirror, it's a newton telescope what can i do ?

Just got my first telescope, and I can't see the edges of the Primary mirror when I don't have an eyepiece in. Could it be that my focuser is to long for the tube? It's a Bushnell 789540. Would a wide angle eye piece compensate for this issue? Thanks great video 👍

Thsnk you... I can visualize it. Cant wait to be successful...

I have an old plastic 35mm film can with a cap. Do I drill a hole in the cap or the bottom of the can?

Brilliant! I'm new to astronomy and bought a 2nd hand Skywatcher 8" Dobsonian which needed a bit of work (I found after I got it home), so in at the deep end! Now mirror cleaned of the dust and mould and all perfectly collmated. Thanks Jason. (On a Skywatcher 200P, 1200mm the allen screws are locking and the Posi screws are the adjusters.)

If we don't have a spare cap lying around, is it possible to do the primary collimation without it? I imagine you can similar to how it was done for the secondary or am I missing something?

18:07 also be careful that the 3 Allen screws don't mark the back of the secondary mirror holder, otherwise they'll cause 'ruts' or dimples in the soft alloy, making the points of these screws to fall into these dimples and making secondary mirror collimation much harder. I found out the hard way... Just put a piece of thin round PTFE sheet or cut of a section of plastic milk carton, to place between these 3 screw points and the back of the holder - this will negate the dimple or ruts buggering up the collimation of the secondary.

So, I haven’t gotten my telescope yet but am trying to learn the some of the maintenance items for a Newtonian scope. You mentioned the bad, good, and precise. You also mentioned temperature fluctuations can distort the collimating. So am I guessing correctly that to have “precise” collimation you would need to collimate these mirrors in the field after the entire telescope has acclimated to the conditions to which you are observing at that time?

i mean this comment constructively, ...your first video was in all aspects better, you took a successful video that did very well, and remade a padded out 40 minute unnecessary version of it, you start off the video by saying " dont get hung up on collimation" then proceeded to OVER explain it , Jason, im a fan, i do like your videos, but please dont make that old mistake that many youtubers do, of chasing a successful video by constantly remaking it, I realise its hard to find new content, but quality over quantity mate, if I was going to remake your original, id do pretty much the same thing but with a proper Cheshire and better sound and lighting.. hope this comment doesn't offend, its not the intention pal.

Hi from Olney Maryland in USA - thanks for your simple down to earth videos - I have a Celestron Powerseeker 127mmEQ Reflector - plan to collimate by your method - but it apparently has a corrector lens? in the focus tube - because it is a Bird-Jones design - my question is - do I have to remove the corrector lens? When I look down the focus tube - with nothing in the tube - I actually see myself in the small center circle of the spider - not sure how that is happening? Maybe a Halloween ghost is messing with me.

What are your thoughts about collimating fast scopes f4, where there is no way of seeing the clips?

Hey Jay, thank you for helping convey the message that anyone starting out doesn't need to worry too much about precise collimation of a Newtonian telescope. I feel that people talk themselves out of a Newtonian sometimes because of it. Although did I hear you mention you wont see more with an expensive telescope? Maybe I miss heard? I think it was near the beginning somewhere, because try telling that to my mate that got his 16" Dob out at the weekend (why does that sound so wrong lol), he was telling me that the Veil nebula looked like a detailed astrophoto through the eyepiece (OIII filter used), and certainly the only time I've ever seen the Whirlpool galaxy in it's entirety was with an expensive C8 Edge HD, it blew my socks off! Smaller affordable telescopes are great of course as they allow most of us to enter the hobby, however I feel it's great to dream of the dream scopes which we may own one day. I know you secretly do this Jason, go on admit it :D

I just want to thank you for your kindness when explain this kind of things, seems that you really enjoying, and that's makes the video even more nice to watch, thanks for share the knowledge, I'm still reviewing which telescope to buy for Christmas, and the maintenance processes, and you make it more easy to understand, again THANKS for share the knowledge :) Maybe a quick question: "Celestron astromaster 114 eq"(423 USD at my country) vs "Celestron astromaster 130 eq" (545 USD at my country) vs "National Geographic 114eq 114mm F4.4 Eq"(325 USD at my country), all equatorial mounts, at first sight the Celestron astromaster 130 should be te "best" but really worth the price diffrence or not?

Eventhough i understand collimation perfectly, i highly enjoy watching these video's. Just as a form of reminder. Thank you! 😄

Wonderful vid on collimating, I used your cap technique and have nearly perfect collimation now, it makes a big difference. I have the Celestron Astromaster 130, and I will say my biggest gripe is the LACK of a center dot on the mirror, I feel like not having that there in advance is just setting up novice astronomers for a lot of headaches. I had to use a piece of graph paper to find that center dot, then added at ring binder reinforcing sticker (very carefully). But once I got it on there, collimating with the cap was SUPER easy, thanks so much for you dedication to astronomy for noobies like me lol!

Can temperature change affect collimation? If I collimate my telecope inside at room temperature, then take it outside in -5 degree celsius weather, would I have to re collimate it outside? Thanks for the video

I don't understand I centre a object in my finderscope but nothing appears in the eyepiece😥

That was very helpful! Thanks so much!

Thanks mate, that is very helpful. Recently, I also made a video on how to collimate fast Newtonian scopes. It gets pretty critical to collimate when using fast apertures.

After a road trip my Newtonian tried the loose secondary mirror. I looked for several outlets to tidy up over months, including with laser collimator, but this video was my savior. Jason, thank you very much, especially for the lesson on collimation, endlessly resolving any deviation in observation. Salut from Brasil!

Question: can't see the entire mirror (3 clips) on the secondary. is the secondary undersized? is it because I have a spherical main mirror? or it's related to fast scopes?

Love to watch your videos to this day. You keep it fun and exciting and that's what's important to me. Thanks you for all the videos that you've put out.

EXCELLENT. Thank you very much. M.

Ok. Next question. It occurred to me after adjusting the primary that the focal point position relative to the secondary could be impacted. How critical is that? I think I have an idea as to how to confirm that using my camera and a stationary photo target.

Hi jason finally got my skywatcher 130m up ready and collimated to the best of my ability quick thankyou for your informative videos on balancing telescope also was fighting it alot! Trial run tonight only waited 4 weeks for a decent night

I love this guy...😁

i am building my own . so this was very helpful thank you.

When in doubt about the Secondary it helps to take the primary mirror out and pointing the now open backend to a light in the room. Then look in the focuser via a collimation cap and adjust the secondary such that you do not see the end of the tube and only things behind the telescope.

Thanks for the long explanation! As you say, it's not difficult.

Hi Jason. Thank you so much for taking the time and trouble to make these videos. I'm gradually watching them all at the moment. Collimation is the one I'm dealing with right now. Just very recently bought s Celestron 130 Astromaster which I think was at least 3rd hand ... haha. I could see it was a little out and the primary needed a good clean so thought I might as well follow your guidance and get it collimated. Just looking for some clear sky at the moment down here in Kent. Did get a couple of cloud breaks a few nights ago and took some moon pics with the mob. phone camera. Soon found a problem with the gears on the finder. Eerytime I touched the eyepiece the tube went down .... hahaha .The tensioner was way too slack and there was no more adjustment in it so sorted that one today and the collimation. Bought a couple of the SvBony lenses that you reviewed and they really do seem to be excellent for the money !! Thanks again mate for all you do.

Hey Jason I'm not a beginner in astronomy and I do love watching your videos and remembering the good old days when I first got interested and in this video I'd say for its subject its the best on RU-vid! This video I hope will help thousands out and make things more easy for people who just bought reflector! I prefer refractors as they just open box and setup then look through it and attach camera or smartphone and get images! Like you I'm always dropping things and so far not dropped my telescope star tracker or eye pieces and would like if you do video on tips to avoid dropping or stuff to use like non slip gloves etc. I do worry about this few times as I'd hate to drop my skywatcher ecoguide 50ed guidescope on ground as I know it would be broken. Do you prefer relectors or refractor? Any telescope that can give nice views or images will be great. Stay safe friend and I wish you clear skies!

Thank you for the informative video. I have since attempted visual collimation of a 12" meade lightbridge. So when I am just looking in the eyepiece holder, If the reflection of your eyeball on the primary is covered by the mirror center mark and all other circles are concentric around your eye = is this not collimated?

I have just bought an optus reflector telescope on line and it is being delivered next week. Will I have to collimate it before I can use it? I have had an interest in astronomy since I was very young, so this will be my first experience of stargazing and I am very keen to get started. I am also hoping to get my granddaughter involved. Thanks. Duncan

Great Detailed Video Jason. I love The Part where You showed the Demo of What a Newtonian Telescope is Made of. These Tips have You helped Me a lot in collimating my Own Scope! Well done, Clear Skies :)

I'm completely new at this, but basically, I'm interpreting that you have to point the reflected view from secondary mirror directly at the center of the primary to start. That makes sense. Wife bought a used 4.5 Newtonian from a friend who couldn't figure it out (probably not even the equatorial mount), and I've inherited the project. They even lost the longest eyepiece, the 10mm (and the collimating cap the manual claims was in the packaging), so I just today bought a set of eyepieces from 6mm to 40mm, plus filters and a 2x Barlow so we can perhaps see things in the sky after dark. I got it balanced and the mount set at our latitude and pointed to north so far using an iPhone compass (not Polaris because it was in the day), and focused on a 14,000' mountain peak about 20 miles away using the finder scope and 25mm eyepiece we got. I can dial it to the next peak over, so I can point the thing. I don't know if it's collimated at this point, so here I am. The secondary mirror is at 45 degrees so the viewer looks into the tube perpendicular to the target, the primary mirror, which then ideally looks directly up the tube to the wonders in the sky above. 45+45=90. Easy math. In this case, degrees, and then hopefully strait down the tube of the scope. 45 plus or minus anything else doesn't look at the center of the primary mirror. If you're not looking at the center of the primary mirror, images millions of miles away will distort, if you can spot a target at all. Continuing now with your video to aligning the primary. Your "flat to the wall" analogy is that the primary should be flat to the bottom of the tube to look directly out, but many things can affect that. As the secondary has to look directly to the center of the primary, the primary has to point directly down the center of the tube. If I'm way off with my understanding, please correct me. Thanks for the videos. I'm going to subscribe to your channel. ...dropping a washer to the floor is better than dropping a primary mirror, I'd think. ...backing off the adjustment screws on the primary before anything is a great idea, so it can be turned in both directions instead of "bottoming out" at stop. That alone is valuable information. Thanks again.

Thank you so much! Your video was so helpful. The washer in the collimating cap was a game changer. 👍

I was shying away from getting a reflector and sticking with my refractor but after seeing your video i've already ordered one.thanks again.Geoff from Ainsdale Southport.

Could I use star collimation for the back mirror? I dont have a center spot on my telescope and I really dont want to break my mirror lol.

Described very well and easy to follow thank you

Your videos are great. I'm very new to telescopes and was reading somewhere how to collimate. My head was ready to explode after the first page. Your video explained the same process but 1,000 times more understandable. Thank you

Much better! Thank you so much. I was a bit confused as well with the first vid. My wife to be just bought me a Skywatcher 200P, and my first outing was a disappointment. I suspected something was not right and I hadn’t even heard of collimation. My neighbor introduced me to the term after discussing with him my frustration. Well I just went down to take a peak into my telescope and was surprised at how far off it was based on your terrific explanation. I ended up spending about 40 minutes playing around with it and got what I think is ‘very good’ collimation without even using a collimation eyepiece. Knowing what I know now, and being the somewhat lazy satisfaction seeker that I am, I doubt I will even bother making an eyepiece for the purpose. Thumbs up! Oh and the 200P has the target on the primary, and some nice spring loaded knurled adjustment knobs, no janky Philips screws.

Although much harder to find a 35mm film tube is also 1 1/4 inch and fits a normal telescope. They may still be around so check around your house.

I Have a skywatcher Explorer 130 like you and i dont have everything to make a collimation cap and im affraid to mark the middle of my mirror, im not sure what to do, do you have any suggestions?

Im trying to get the secondary mirror aligned. Even tho I get everything aligned or what looks aligned, I can never get all 3 clips. Could it be my eyes as I am far sighted, or am I still doing something wrong. I can't get all 3 clips in sight no matter what I do... can someone please advise me...

From Australia Thanks. I just check and I do need to collimate my telescope. Thanks

I think it makes a huge difference with a decent quality telescope. I tried to collomate a cheep reflector which had only screws and no knobs. Needing to hold a screwdriver really does make things a lot harder, especially when I am trying to keep my 3d printed Cheshire in the homemade 0.965 to 1.25 adapter. It got good views of the eclipse in the end, but the whole process reminded me why I chose to get something better.

Hey Jason first of all you're my favorite guy on RU-vid..I love your attitude and enthusiasm for astronomy. Second, I know this is an old video and u may not ever even read this message but I just have a question. How do u get the secondary lined up perfectly under the focuser.. in other words, how do I know if my secondary should be closer or further away from the primary if u get what I mean...I enjoy collimating my telescope and don't have any issues at all with it but let's say I'm a little too close to the primary or I'm not quite close enough, I feel like I can still get my scope in collimation.. the reason I'm asking is because I recently took both mirrors out to clean them and I had never done that before so I wanted to make sure I put my secondary back in the correct position forward and back if u get what I mean.. tilt and rotation I have no issue with.. thank u and please don't stop making videos..I think I've watched every one of yours at least twice if not more

Hi Jason. Greetings from Yorkshire. Great videos! An easy way to imagine how collimation works is to get the viewer maybe to look at their phone screen while it's off. If you imagine the phone screen is the secondary and the reflection of the face in it is the primary, then when you tilt the phone screen in different directions in very small ways the face appears to move away from centre. Isn't this essentially what is happening when the telescope is out of collimation? Cheers Jon.

I loved every minute of your video 😄 What an entertaining explanation that does the job perfectly

Good job

Hi Jason nice video but I am a bit confused about how to collimate my secondary mirror without a laser. Also really enjoyed the livestream last time you should do another one😃

I need to say the this video is brilliant. There is so much passion in you presenting this. And I as a complete beginner am now absolutely confident to be able to do that. Thank you so much.

My telescope looks zoomed in, I can't get all brackets in view, they're too far from each other

I cant see all the clips on my 130slt no matter what I do. What am I doing wrong?? Help!!

@small optics Thanks for taking the time to help people with this. You're the man!

I 3d printed a collimation cap and its worked great for me :)

Thanks a lot

Problem is, i have a bird Jones type, and i have no clue on how to get it right

thank you for this tips i just got my self a used powerseeker 127eq , owner said it was collimated but i could be sure after watching this and other older videos of yours , i think he is telling the true i can't find any problem again thanks for the awesome video

Can you collimate without removing the primary mirror? I am clumsy as all hell and like as not I will break that thing if it ever comes into my hands. I'll be honest, maybe Im dumb, but I still don't get it :/. Like at all. How does turning screws make the mirror go up and down and whatnot? Also, isn't loosening the mirror gonna make it bounce around the place at the slightest touch? How do I move the screws AND check the focuser at the same time???? All of this is so gosdharn confusing.

As a newbie, I really appreciate your videos. I was given an older Polaris 114 mm telescope, which I have been rebuilding, as the mirrors were both corroded (new ones installed). Now I have been given an all metal R & P 1.25 in focuser to replace the original 0.965 in focuser. Any advice on how to balance/calibrate the new focuser? It doesn't sit fully on the tube (maybe for a slightly bigger tube), and has 4 nuts and bolts instead of the original 3 bolts. So how do I know it is square/perpendicular to the diagonal mirror? Any advice is appreciated

Hey. Could you do a video on the need (or lack thereof) for thermal equilibrium out of dobs? I have a ad12. And don't use it since I'm convinced scope needs time to cool

I can’t find out how to fix the spider does anyone have any videos of how to do that?

As beginner your video helped me so much, now collimation is easy thing for me. Thank you!

😂 love your special effects.

Like for the light beams

Than you so much.

Allen is a type, not a size.

Northern California...

I think i go with laser..

I think this is the best collimation video i've seen. Simplified but comprehensive if that makes sense. thanks.

The k.i.s.s. method 🙂

Utoobz 'algorithm' caused this to come up for me and I watched it to see what you had to say. While I'm sure someone can do what you say to get a scope viewing 'capable' I'm not sure it gets it that good. I've been an amateur astronomer for over 50 yrs and I learned a completely different way to collimate a newt. It's not that hard and when you think about it it just 'makes sense'! A basic understanding of what we are trying to do with the mirrors makes the method I use just second nature. It does require a couple extra 'steps', but done once they rarely need to be done again. Step 1 - center your main mirror in the mirror cell. This requires you to remove it from the tube and check that it is in the center of its cell and placing shims if needed to center it. Replace it in your tube and remove the secondary from the spider. Step 2 - Now using a small scale measure each arm of the spider and see if the distance of the center hole in the spider measures the same along each arm to the tube wall... adjust by loosening and tightening the screws that hold the spider. Step 1 & 2 need not be done ever again, usually, unless it falls out of your car as you're driving to your dark site. Now to adjusting the mirrors. With a center dot/mark on your mirror (you did put one on it if it didn't have one when you had the cell out...right?) look thru the center hole in the spider and observe the spider against your main mirror. Use the adjusting screws on the back of the main mirror to center the spider hole with the center mark of the mirror. You will now NEVER touch the main mirror adjusting screws again! Why? The mirror is perfectly aligned with the tube axis! If at any time you turn those screws after this step you will change that tube alignment which makes the optical axis not 90° going out to your eyepiece. Replace the secondary mirror in the spider and center it in the eyepiece holder so you see the main mirror is aligned and not off to one side. Now using the adjusting screws on the secondary align the images so they all coincide correctly using the eyecap with the pinhole. 'Perfect' alignment! This is where 'knobs' are useful at the secondary as this is where all the adjusting happens. (Checking the mirror/tube axis alignment by removing the secondary should be done as the weather changes but I have found my scope seems to hold very well)

Great explanation. 👍🏻