Collimation Made Easy Understanding Collimation

hello welcome to my channel small upticks my name is jason now uh in 2020 which was last year at the time of recording this video uh i uploaded a video called easy collimation an easy method of collaborating your telescope no lasers involved and it's probably my well it is my most successful video it's out of over 45 000 views that one uh but there's a there's a few questions and it's the same questions that i could see in the comments keep cropping up um and i and i thought well you know this is this is more than once now and it's the same sort of question and that's my fault i do apologize um you know sometimes making these videos it can be a little bit difficult to uh you know actually think back to the actual abc's of the hobby and uh you tend to forget um the the basics of uh certain things so i i'm hopefully i'll cover all those questions and loads more uh so after watching this video i can assure you collimation is going to be a breeze and you're going to understand it all and it's it's all going to just make sense in my book there are three types of collimation bad collimation good collimation and precise collimation and if you're a beginner which uh you you more than likely are because you're watching this video the only one you need to worry about is number two good collimation that's all that matters in a newtonian type reflecting telescope because the chances are you're just starting out in the hobby you've you've heard about these type of telescopes neat collimating and you've heard probably all kinds of horror stories they need this they need that you need to have to have a laser they have to be done every single night off of it's not true yes they do name maintaining they do need collimating so as a beginner you're to probably have equipment like this just an entry-level telescope just basic equipment basic doesn't mean inferior equipment though um it's i don't really like the term entry level you know what i mean because you know more expensive telescopes further up the range are just going to show you exactly the same things as some of these uh entry-level telescopes show you so you've got basic equipment you've you know and one of the biggest problems that beginners do with this type of telescope is they can get obsessed and worried about collimating and in in actual fight do more damage trying to collimate the telescope then they're doing good uh not permanent damage but they usually uh you know i've i've seen i've seen some quite disastrous attempts in the time of uh beginners you know and i'm not laughing you know taking uh because we've all got to learn somewhere you know what i mean it's it's it's it's not an easy thing collimation but it's certainly not hard trust me so let me just explain what i'm waffling on about here about this precise and good and precise so as a beginner just getting your telescope into good collimation is all that's going to matter the only time you need to worry about precise collimation is if you are a serious astrophotographer with serious um a telescope serious astrophotography equipment they all cost serious amounts of money because it's in astrophotography where that precise collimation really matters but for just general beginner astronomy or fun astronomy as i like to call it as a hobbyist you just want to get out there and enjoy the night sky with your new telescope or with your telescope so collimation should be just something that you've got to keep on top of but just keep checking it but certainly don't get ocd about it because this is one subject that real people really can and i've seen it with a few friends and and colleagues over the years they really do get ocd about collimation um but i'm going to show you some simple tips and tricks where this is just going to be a breeze now if this is the first time you've ever attempted to collimate a telescope or or whatever you're going to first need to know what you're trying to achieve um there's no point in you know jumping in at the deep end before you know how to swim if you get what i mean so if i was to dismantle and take all the optics out of this telescope or any refl newtonian type reflector no matter how big or small it is the optics would look something like this now these are just models i've mocked up for this demonstration and i think simple models like this are going to explain it more than graphics which i'm not very good at anyway putting fancy graphics up so uh simple models like this will do it just do it fine but this is a telescope i'm holding a telescope whether it's the largest in the world or the smallest in the world whatever this is what a newtonian telescope is made up on okay a uh a spherical sorry not a spherical a spherical shaped anyway a round primary mirror which is usually concaved okay well it's always concave not usually always concaved okay and a smaller secondary mirror and these are just simply this is a i'm not trying to insult your intelligence here i'll get to the point in a minute this is at the bottom of the tube okay this is here at the diagonal where the eyepiece is now the idea of collimating two mirrors is to simply if i was to now one's at 45 degree handle and i'll get to all that in a little bit in a short while but as you can see there's two light little dots in the i don't if you can see that bang in the center of both mirrors now if i was to put those dots face to face now like this these tell you these uh mirrors sorry are collimated in other words they are in the center of the center of what each other this is what we're trying to achieve when we're collimating a telescope now if i just um actually we'll do a to magic video editing and make some light beams appear on these and i'll explain what they are in a second so give me some light beams that's about as good as it gets with special effects on this channel right let me explain i don't mean light beams that was the wrong word what i meant is the path of light but what this is demonstrating now is this is our primary mirror and this is our center of the mirror and i've extended the we'll call it light path if you like or the center of the mirror okay now exactly the same thing i've done with the secondary mirror now remember the secondary mirror is at like a 45 degree angle in fact that's more like 45 degrees so i've extended the center point of this mirror also now collimation is simply this you're trying to blind the centers of each mirror up so they're like that okay does that make sense now when you collimate in a telescope excuse me it simply means you're adjusting the mirrors so you're either pivoting it up putting it down left and right like that so if i show you from there that way around hope you can you you grasp on this so if i i'm pivoting the second the small mirror now and as you can see they don't touch anymore that's out of collimation that's out of collimation and that's in coloration it's hard to keep these still now popping all over the place um but as you can see the same is with this with the primary mirror now we're not doing this okay now because it's impossible to do that if you think move the mirror up and down because it's housed in a tube so that part of the centralization and same with your secondary mirror it has what they call the spider at the front okay so that that up down left right is already centered it's these tilting backwards and forwards of the two mirrors and we're trying to align the two center points up that is what collimation is so now you're armed with that knowledge you know exactly what we're trying to achieve at the telescope when it comes to collimating both mirrors you will always always start with the small secondary 45 degree mirror first and we this is the one you need to collimate and get right first if this was not right you're not going to stand a chance with the um with the primary so let's just uh let me just explain what you are trying to achieve here now if this was an invisible telescope we've already you've seen that this is the light path it's going down at 90 degree angles because if you imagine the light or your eyesight is this uh second pipe cleaner here it would it would come down or up the light would travel up in actual fight but let's just say it's the line of sight your line of sight would go down and hit that 45 degree mirror exactly like that see and can you see that everything's at right handles it wouldn't be like this it wouldn't be like this okay it wouldn't be like this well that's it that if it's like this then you've got focus of problems your focus is not square but i'm not going to get into that it's very rare that that's that that crops up but sometimes it does so we're just going to assume that your your focus is nice and square so the light path would be like that nice and straight and as you can see when it hits that 45 degree out it's going out at right angles exactly 90 degrees straight down the tube towards the center of the mirror this one it would be in collimated perfectly collimated if it's uh doing this okay so now you know what we're trying to achieve with the secondary mirror now before before we even use any tools or aid to assist us in collimation the best tool you can ever use is your own two eyes now i can tell and i'm not this is no bragging rights or anything like that i i'll be able to tell just by looking at a telescope just by taking the eyepiece out looking down the focuser whether it's in reasonable con collimation is and any experience seasoned astronomer will be able to do the same and this is the best way of checking your telescope by just using your eyes and learning what it should look like when you look through the focuser now what i'll do is i'll i think the easiest way to do this is flash some photographs upon the screen of my telescope i don't know whether there'll be screenshots from my first video or um or i'm going to be doing some news but anyway there should be some photographs now if we look at this first photograph now if all i'm doing here is i've got the camera literally there okay looking down the focuser so we're looking straight down there and that that is the first key you've got to look at is that everything is in like concentric circles what they say um if i outline them there you'll be able to see that you've got a circle a circle a circle now here's some bad examples of what i mean sometimes if we have a look at the um i'll show you here now we'll i'll just get into uh it might not focus that close so i'll again i'll i'll throw some photographs up you've got a little screw in the middle of your spider all right if you have a look there you will also notice three smaller screws now these could be hand screws or they could be like an allen type screw um you just have to check your telescope what type they are these are the adjustment screws that we're going to be using to adjust the um the secondary mirror now what you want to do is just very very gently start loosening one of them off just just one of the allen allen screws off and this is going to give you access to actually put your hands in the telescope and like i said i don't know if this is focusing in the telescope like that and you'll be able to actually turn the secondary mirror look down the focusing tube as you're doing this okay and um and i'll show you some pictures you'll be able to see if it's rotated too much or and that's the first thing you need to do make sure that the amount of telescopes like i say in um certain um times i've checked telescope where this rota and this lighting is rotated so far how they've managed to see anything i don't know so again i'll show you the photograph what it should look like and what it's over rotated look like and that could be either way okay so um the best thing to do is is to take a screenshot of that photograph i've just shown you and compare have a look in your telescope right now one pause the video have a look we'll compare does your telescope look anything like that now another good thing to look for and what's important that you do see when you're looking down there is all the brackets that hold the mirror cell in place you want to visibly see all three black brackets make sure that the second rumor is rotated it's correctly there and that you can see all the brackets if you can't all right start from and start in order start with the rotation first make sure just loosen what like i say you don't have to undo the center the center screw here um just by loosening one of these allen small allen crew screws or if it's a thumb screw it'll still um you'll still be enough to rotate it excuse me so that's the first thing to collimate if you and like i say if you can then once you've got it and you've adjusted the uh this the allen screw so sorry i'm jumping ahead of myself so once you've loosened them check okay that you can see all the brackets if it needs lifting a bit if it's you know it wants to i can say i can't emphasize the word as long as everything's central you are going to be fine the telescope will be fine okay i've shown you them bad examples where um i'll show you what i'll show you some examples now of a mirror too high and too low okay so this one would be too high now that simply means it's been it's like as it's in the bracket um where's my little model gun if it's in the bracket like that remember we're trying to line up okay if it looks like it's in the picture that means you've got it set too high that way this is we're on the secondary mirror okay got it set so you just need to either tighten the top screws and loosen the bottom one off that's right isn't it yeah okay and that's going to bring it back down uh so it looks like it's in the correct picture if it looks like this okay in the picture you can see that it's tilted too much to the right or my left no my right you're left okay so you can see that that's what you're trying to achieve that picture basically so that's going to be your adjustments don't worry about your primary just yet we're going to come on to this remember was we're on the secondary this is what's important remember guys this and this isn't um to get your telescope in precise collimation this is to get your telescope into good reasonable usable usable collimation that you can you know not have to worry about the telescopes in bad collimation that's what i'm trying to get to so if you've uh got that far and you put you when you look down your focuser it looks like in the picture okay you have collimated your secondary mirror now take your time with this stage all right just just take your time move these screws very very gently never over tighten anything these uh especially the little if you've got these little allen screws make sure you're going the right way or okay because they can't snap off they can break off i've known them to to actually break off so take your time all right the absolute safest way of avoiding breaking those uh little uh grommet screws if you like is to just take a little tiny bit of tension off this center screw and by taking releasing a bit of tension off that you'll find that everything moves okay so just remember it's on like a like a push me pull me sort of system so if you're tight if you were to tighten the bottom it would lift the mirror um if you would loosen the bottom and vice versa so it's just screws pulling on each other and same with the primary it's exactly the same remember the primary's not going to move up and down um the the primary uh both mirrors move this way like this not up and down so if you've got this far you've done well and this is your uh secondary mirror done we're going to move on to the primary now and get that collimated now as you can see if you've got as far as doing your secondary mirror this is off the battle you're halfway there now i mean the rest is a breeze um so we're on to the primary mirror now now this uh brings up a question that's been coming up a lot and it's kind of confused quite a few of you actually and i apologize for that um and that is the positioning of the center spot um now in the video that you may or may have not uh have watched i'll leave a link to that don't worry in the description in my first video on collimating instead of a uh center spot like this okay which is what you'll find on a lot of primary mirrors again this is just a model remember um i used a star just a sticker of a star and uh i've run out of stars when i re-spotted this at the time and i must get some marks i miss it actually and that is where the star is placed it's placed in the center of the primary mirror now the reason mirrors in telescopes have this center spot if you could that's what it's virtually called a center spot it's to help and aid us with collimating okay that's why they have it in now you may or may not have a center spot on your mirror just have a look i know this didn't come with a center spot i had to spot it myself and that's what you can do um it will involve taking your telescope mirror out don't worry there's nothing to be frightened off because remember at the end of this you're going to be a collimating expert so there's nothing to worry about and to help you even more i have done videos on mirror removal and center spotting again i'll leave a link to those two down in the uh description because this center spot it doesn't want to be put on willy-nilly it wants to be put on center i mean precisely in the center of the mirror otherwise it's a waste of time and it won't help you it'll hinder you okay so on to the primary uh yes so that's why we have a center spot and that is where the stars plays to answer that question has come up so many times you know um where is the star and like i say i use the sticker of a star i'll probably be flashing pictures up uh but it doesn't matter just a simple sharpie dot you know like a normal sharpie just doing the method that if you look uh at my video on center spot in if you just use the just a simple sharpie that is harder to see but if you've got good eyesight just just a dot precisely in the center will be fine another question a lot of people ask is doesn't that affect the view well no because in actual fight the the center of your mirror is unused it's uh if you think about it there's a secondary mirror block in the center of your mirror so it is pretty much a dead spot of the mirror um the active part of the telescope's mirror is this part right around here and towards the edge uh the center is a pretty much of a dead spawn but we need that silver collimating so that's cleared a few questions up there so um hey hey we have to drop something didn't we for all those who don't know i usually drop something every video this time it's just a washer here we go i don't think i'm touching anything expensive today if we're okay right so um let's move on to my favorite method of getting your prime room um mirror something like in car well actually not something like in collimation and that is with one of these and this is a collimation cap now don't worry at all if you haven't got one of these because every one of these here i've made okay they sometimes do come supplied with the tel with your telescope and you may be wondering what on earth is that thing well after this you'll you'll know now this what collimation cap basically is this now this as you can see is just made with a dust cover from an eyepiece uh an old an old dust cover i've got um i've simply put a hole again precisely in the center it's important that you do get it dead center just a a pinhole slightly bigger than a pinhole and then just lined it with some white paper inside what you would then do is take an old barrel or an existing barrel just off an eyepiece you can always put it on back on after you've finished using it and it's always a good idea to put maybe a few little blobs of blue tack or something around the the barrel just so you get a good snug fit when you put it into this collimation cap this is basically it that is a collimation cap okay now i'm not going to go into great detail of using this because i did in the last video but i just want to clear a few points up over exactly what's going off when you're using one of these collimation caps uh just show you some more examples another way you can do it this is one of my favorites um is instead of putting white there you can see i've put a a shiny washer just in the bottom of the cap again just a pinhole in there and like a shiny washer like that and again you just would add the barrel and there's a collimation cap now have a look at some of your dust covers that come on your telescope because these if it's one like this okay again they make excellent collimation caps um and as you can see all i've done is done the same sort of thing with this one um a simple washer in there and then just drilled a very small hole through the center okay so that is a collimation cab they come in different uh shapes and sizes and some have uh slightly uh some are just purely like a mirrored surface there there's not like a washer but a wash is just fine and i'll show you exactly what you're going to achieve or what you're trying to achieve when using one of these okay i'm assuming you've now got you've made yourself and or acquired a little collimation cap now a good tip when you using a collimation cap is to do it in the daytime um ideally you don't have to you can do it under artificial light and what you want to be doing is pointing your your telescope towards the light you'll you'll see why in a minute now the way you use a collimation cap you've already made it remember it's just a simple device like that just use it like an eyepiece it will go straight into your focus so like that okay and you would spy down just use it like an eyepiece now if you have got a center spot on your mirror which uh it's i don't know you won't be able to do it unless you have got a center spot so uh that's the if you that's the next thing you need to do people that haven't got a sense but go and get your mirror center spotted like say go and watch my video it's not scary trust me but we'll assume you have got a spot on your mirror and when you look down your collimation cap on when you look straight through like this you're going to see this and as you can see what you're seeing there is a reflection of not only your primary mirror but you can also see the spider all right so just get your head around what you see it what you want to be looking for now is your center spot okay now your center spot will be reflected back where uh depending on how you've done your collimation cap um like i say when i did a star what i was trying to do is imagine i think this will display uh explain it's a little bit better imagine that this i'm looking straight down uh the collimation cap all right so i'm looking down it like this but we can see it from this handle and you would see the spider at the front okay and you would also see your um sensor try and drop it try not to drop it again your center spot like that that's what you want to be looking for and this is why you need it nice and bright plenty of light coming into your telescope and uh you may need to move your telescope around to just catch the two so you're going to be looking for remember this um this circle here on my model represents the washer uh or this circle here on your collimation cap okay so we're looking straight down like that and this little washer here is going to represent the center spot on the primary mirror okay i hope that makes sense now what you may find is when you look down your center spot maybe slightly like this or it may be slightly this way i don't know if that's showing up on my black jumper uh but whatever the idea is to try and just by moving i'll get i'll explain the adjustments of it in a minute the idea is to get that center spot in the center of your collimation cap basically okay and i hope that makes sense um and obviously in in in a design like this it would be you'd be trying to line it up in there see if i can do it this way looking through like that sort of thing okay moving it around and just so you get it in the center like that this is what we're treat achieving with the uh collimation cap and it was confusing a few of you because i didn't explain really what the camera was showing i did have i did this live if you go back to the video um i actually do this live with the camera down or just in the mirror and people can't understand what they was looking at really uh where the star was coming from uh and like i say i used to start in that video uh not a center spot so that's what you're seeing it's just reflections so let's go on to how you actually adjust the primary mirror okay the business end of a newtonian reflector now this is probably well is the most basic um telescope i've ever ever ever owned with how these collimations uh adjusters are set out they're just simply phillips screws and it's still still baffles me why sky watcher did this on these uh telescopes i do not know but they did but anyway hopefully you will have thumb screws uh if you if you have a look around here now what you'll find um if you have a look around here if you have a look around at the bottom of your telescope is what i should have said um what you usually find now this isn't always the case but i would say 85 percent that it usually is um you'll find that the adjusting screws the ones that are going to move the mirror in and out are further in all right simple as that they stick and the locking screws the ones that lock it all down so you can't adjust the mirror anymore usually are protruding a lot further out now find out that's the first thing you need to do is find out which is which but don't get confused at first if you're a beginner or it's the first time you've ever moved these because and the way to do this is to put your collimation cap in okay look through it and adjust it that way don't adjust then look through obviously because you're not going to know what's happening and with the coloration capping you're really going to see that center spot move um so uh but like say don't uh when you first do it when you alter the locking screws you may notice that it moves a little bit all right the dot the the center spot will move a little bit but then it'll stop moving the more you turn okay that that's when you'll know it's the locking screws this the the adjusting screws the mirror will be moving all the time whether you're screwing in or whether you're screwing out okay you'll find that with the locking screws the lonely screw in so far and then they'll stop uh and then they'll just be finger loose that you're able to just scrum all the way out basically um so that's the way you need to identify your locking screws from your actually adjusting screws so the first thing we need to do is slightly loosen just two for now two of the locking screws off now usually it's only two that you have to adjust um they have to be pretty much in a mess to um you know have to do all three and usually it's only two you have to collimate now a little tip about this and it's a again another question that keeps cropping up and that is people saying they're turning the screws to um alter the mirror and nothing's happening now this could be one or two things they're turning their lock-in adjusting screws which i said will well they'll move the mirror a little bit when you first undo them and then they'll do nothing all right and that could be that reason another reason is is that they've got the um adjusting screws fully fastened down now if they're fully fastened down then they're only going to go one way they're not going to go the other all right now that's a little tip i want to come to um if we go back to what i was talking about the start of the video with the two models all right the two mirrors i don't know where the other one is where is it oh it's here i haven't got the light path in remember we said that if they were flat i'll take that out for now if there was flat they'd be collimated okay now the only difference is from that and bang in the center of each other yeah like we said at the start of the video these mirrors will be at if you imagine against a flat wall like this this is how they're going to be they're not going to be like this the only reason we have to adjust them is because what houses them the metal or the plastic that's housing them well it's usually metal moves it's as simple as that you know why when you when you you know what it's like at night time the the house creaks and cracks a little bit when things are cooling down that's because the certain materials just moving and adjusting to the different temperatures this happens in telescopes so having it totally flat against is not going to always work because as the housing slowly you know uh warms up or cools down it's going to move a little bit and tiny tiny movements will knock telescopes out of collimation this is why we have to collimate but just imagine but like i say going back to the start where everything's flat at 90 degrees well there's your first there's been model pieces oh dear i'm glad we're building work we're a lot stronger than that anyway um yeah so imagine that we're at 90 degrees now this way okay we're vertical all right we're absolutely straight plump straight that's your first battle remember this is all part of collimation we know that this up down left right was centralized so start this way start with the mirror pretty much vertical flat to the housing at 90 degrees the way we do this is once you've identified your um your adjusting screws okay fully all right so loosen your locking screws off first uh sorry i think i was uh scraping the microphone then that must have sounded awful right so fully um loosen your locking screws off and fully tighten these down okay your mirror cell screws so you've got the the mirror absolutely tightened down the bangers opposite of what i said earlier when i said the you know you can't move it because it's fully locked into one place but this is your starting point you know now that the mirror is is at right angles with the tube okay because it's in the housing all the threads even now what you want to do is go back um have i got a screwdriver yeah here we go i'll show you with this screwdriver because it'll be uh it'd be easier to uh me show you so we've done it we've tightened them fully down yours might just be thumb screws all right um or whatever they are but they're fully tightened down now now place your thumb on top all right and go round one and clasp this as one full turn one so your thumb goes from top to bottom all right so we're loosing the mirror off now so one all right and do that three times so you're gonna go so we're fully tightened in and now we're gonna go one take your thumb back round to the top two take it off thumb back round to the top three do this on all three adjustment screws and what this has done now is giving you leeway to move in and out for fine adjustments and it's also pretty much set your mirror up nicely at right handle degrees okay sorry at 90 degrees at right handles with the tube so you've you know you can see where i'm coming from you've like you've won half the battle already so from there then you would uh and do all this with the capping keep checking you know just uh keep checking everything's okay this business end you know if you need it a bit of reassurance right let me just spin the scope around now if you've got your center spot in the center of your collimation cap you've cracked it guys your telescope's in collimation now it's very rare you have to touch your secondary mirror once you've collimated it all right it's very rare that that comes out of collimation what you may have to do is just touch up your um your primary every now and then all right just just throw your collimation cap in make sure that it's in the center that's that's all you're doing remember you're looking um the only thing to concentrate on is that area of the collimation cap and the center dot so the open space of the collimation and the center dot right of your mirror um ignore everything else around you and because that's where people were getting confused about um when they said they were looking through the collimation cap when i had the camera up they couldn't understand where the star were coming from like i say the star was the circle um just a little quick no um not all spiders are fixed like this check your spider some do have adjustments on this part um of the spider now um that's something else i would advise you to just look a few videos up on adjusting the spider and getting that centralized it's not difficult and it's just using a ruler and a little bit of common sense uh but that's something just to check for um if you have got an adjustable spider you'll know because it'll have like a bit sticking out all right around here it'll not just be all flush so that's something else to check but um if you haven't don't worry about that and i think guys i've about covered collimation please please feel free to leave me any questions you may have uh to towards this subject because i know it frightens a few of you and it puts a lot of you off buying one of these amazing type of telescopes and it shouldn't um like i say there's a there's a lot of nonsense out there uh with collimation you may have noticed i've not mentioned lasers once there's a good reason for that i think it uh justifies an entire video on its own of uh why i personally don't like using lasers on these type of telescopes so i think that's about it guys um if you've watched this far thank you so much for watching and i really hope that it's cleared a few things about colormating and don't forget please just leave me a question in the comments i do read all the comments and uh if i do miss a question i'm not ignoring you uh this algorithm is it that they call it on youtube it's very messed up at times and i don't get all my note to fake notifications i have to keep checking on videos and i but i usually get around to everybody eventually anyway guys thank you so much for watching don't forget like subscribe all the usual stuff in the meantime keep these telescopes in good collimation remember we're not bothered about precise um but don't get lazy and i will see you on the next one bye for now [Music]

Channel: Small Optics

Views: 58,511

Keywords: astronomy, astronomy for beginners, astronomy for dummies, how to collimate a telescope, collimation, stargazing, the night sky, telescopes, skywatcher, mirror, telescope mirrors

Id: Xzus4oA8Ses

Length: 40min 34sec (2434 seconds)

Published: Fri Nov 12 2021