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Collimate a Telescope without a Cheshire


Hello in this video I’m gonna be showing you How I collimate my newtonian telescope There are 3 basic steps to collimate a newtonian The first step is to make sure that the Secondary mirror is aligned under the focuser The second is to make sure that the secondary Is aligned towards the primary The third step is to align the primary mirror Back to the secondary mirror Okay so why do we need to collimate newtonians Well because newtonians have more moving parts
than refractor telescopes Whenever you transport newtonian telescopes
and you’re in the car You hit bumps the secondary and the primary
mirrors can get out of alignment When you have a telescope such as this “SkyWatcher
Flex Tube” It has an adjustable truss So every time I collapse and expand it The secondary could also be out of alignment Now when mirrors are not collimated the starts
will look Like they are elongated and be very difficult
to reach focus If not impossible to reach focus Secondary mirrors require less adjustments
than primary mirrors Because they should be secure unless they
are really worn out Okay so the first step is to align the secondary
mirror to be Directly underneath the focuser This is the secondary mirror And this is the focuser You’re gonna need the following things You’re going to need a collimation cap And two sheets of paper preferably having
different shades This one is white and this one is brown The first step is to insert the collimation
cap into the focuser tube opening And then I’m going to insert the brown sheet
inside And face it out this way The goal is just to block the primary from
being seen by the secondary And to avoid any distractions Then I’m going to insert a white sheet against
the wall here Behind the secondary mirror which should create
more contrast When I look through the collimation cap Now I don’t have a cheshire or cheshire So I’m using a collimation cap with a hole
in it I don’t know if you can see the hole Can you see the hole Okay And I’m going to be using my smart phone I
have a camera phone What I do is I take a picture of it through
that hole Let me try it again There we go Okay I tried anyway So you should be able to see something like
this Okay and then I get a ruler And I measure the distance from the edge of
the field of view To the beginning of the secondary mirror And then the same thing on the other side From the edge to the edge of the secondary
mirror If they’re not If they’re not the same value then that means I have to move the secondary mirror either
this way Or that way And to make that adjustment In this telescope it requires a phillips head
screwdriver The adjustment screw is right here To loosen it you turn it counter clockwise And then you make the adjustment Now one thing to watch out for is that The secondary mirror also tilts this way So that it can turn up or down Once you’ve realized that it’s already centred
under the focuser You’re gonna want to make sure that that’s
also square with the focuser And the way you can tell that is if you take
a picture of it Using your camera phone The primary mirror should be circular It should be even all across around the secondary
mirror Okay so in the first step you noticed that
the telescope was Already in a horizontal position And that is because it needs to be in a horizontal
position In order for you to insert the sheets of paper
inside But because you don’t need to make those adjustments As often as the next steps You have to remember that your telescope is
in this position Because you don’t want to be dropping any
tools And hitting your primary mirror So in this next step you’re going to be Aligning the secondary mirror with the primary
mirror And we’re gonna need to use an allen key tool And to make these adjustments there are 3
head screws On top of the spider So when I tighten these screws It’s actually gonna push It’s gonna push the secondary towards the
primary mirror But only at a certain angle And every time you make these adjustments You look through your focuser with the collimator
cap still inside So that you’re in one only in one confined
area And then once you can see all of the clips
the 3 clips of the primary mirror Visible through the secondary that means you’re
already in alignment Remember that you wanna maintain tension across
the 3 the 3 screws here Otherwise it’s gonna be too wobbly and every
time you transport the telescope You’re gonna have to redo this step again The third and final step in collimating a
newtonian telescope Is making sure that the primary mirror is
aligned with your secondary mirror Now whenever they say that every time you
have to setup a newtonian telescope For observing you have to collimate it This is the step that needs to be done Fortunately it is also the easiest step to
do And you only need a tool such as a laser collimator Now this laser collimator is not very expensive I got this off eBay for around 50 dollars
and it works But make sure that it’s true There are videos out there to show you how
to make sure That the laser is straight by turning it around
like this I’m not gonna go into detail But this laser collimator is definitely straight
and collimated First step is to I’m gonna remove the collimator cap I’m gonna turn on the laser Which is gonna be red So it’s not going to affect your dark adaptation
when you’re out in the dark site And I’m gonna insert it into the focuser tube And I’m going to adjust the distance of the
focuser As if I have a an eye piece in there so in
this case I think it’s around that much Then I check inside the telescope And make sure that the red dot is pointed At the donut that is the second That would be the centre marker on the primary
mirror Once that is centred That means your secondary mirror is still
collimated Now we move on to adjusting the primary mirror Now the laser collimator has what looks like
a target So it has these concentric circles Where the red dot hits Not inside the hole There’s a hole there And the goal is to make sure That the red dot goes inside that hole Now this telescope has 3 adjustment screws In a push pull configuration To make adjustments I first loosen these smaller knobs And then I turn Everytime you turn The red will move across the target Okay Each one of these knobs corresponds to a different
movement Once the red dot disappears into the hole That means you’re collimated

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Comments
  • 12"…wow that is big.

    1. Can you see Uranus, Neptune, Ceres, and Pluto through your 12" Newtonian telescope?

    2. What is different between Newtonian and Dobsonian telescopes?  Thanks

    3. Have fun to find any object.

  • i just bought a 8inch dob first one and man am i having problems collimating it my issue is i try to set the secondary im able to get a nice circle and i measured it and its  great my problem is when i take the paper out and look the primary mirror is way off is this normal and to i just adjust the primary till i can see it in the secondary or am i doing something wrong when i adjust the secondary and another thing when i bought this he game me what looks like a sighting cheshire its long it has wire cross hairs there a side opening with a 45deg its not laser so how di i set a the primary with it i cant find any videos that set up a dob without a laser just using a old school cheshire

  • Can you say me more about your light shroud on your Skywatcher FlexTube?

    I think to buy this telescope and i had seen the astrozap solution… good but expensive.

  • My telescope needs a small collimation, but i still not shure if the secondary mirror is the bad one or the primary mirror. I just have a cap.

  • Dear Michael: Are you sure the secondary view must be centered in the picture (4:00)? I was working on that and I found that the secondary shift must cause a shift also on the picture. I kindly request your opinión, please take a look to this short video
    https://www.youtube.com/watch?v=OCe9HiK6cu8&feature=youtu.be
    Best regards

  • My question is that when I connect SynScan to mount, i get message on that

    No mount detected, start in standalone mod

    I bought bk mak127(1.25 )+ az synscan two days ago, first day it was working and mount was rotating around now what could be the possible reason for this error message.

  • My 8" meade LX70 Didn't come with anything to collimate it with, and the instruction manual is extremely vague how to go about it. So many different sites and resources say I need a Cheshire or laser collimator but I have no clue what any of those things are. It''s extremely frustrating.

  • Hello! I've been trying to collimate my telescope for a couple of days unsuccessfully. The primary mirror is in place, and the secondary mirror is center under the focuser. The problem is that the reflexion of the tube on the secondary mirror is not centered. I have a couple pictures where you can see it. Could you tell me where can I send those pictures so you can see it and give me your opinion? Thanks!

  • nice video, I'm learning! ☺
    planning to buy Celestron PowerSeeker 127EQ
    for my 3 yr old son and for the family. I think this is the
    decent model to start stargazing.

  • The spider vane screws which are attached to the telescope have been loosened Does the spider vane need to be adjusted or aligned and how do you center it again?

  • i hoped you could help… I am seeing perfectly ROUND stars but I can see the crosshairs from the scope .. i have collimated my newtonian 150/750 many times with laser collimator to perfect precision!

    HELP!

  • Help help my telescope just falled from the stand but I checked the mirrors haven't broke or any scratches but I need help on the first step my the collimating cap please reply when I see stars there I see the cross and the secondary mirror in the way what do I do help please tell me

  • Nice video. I made a collimation cap from the focuser plug by poking a hole in its center. I go without tools also. The paper trick is new to me. Never thought of it.

  • In the very first step you are completely blocking view of the primary mirror by the larger sheet of paper of a slightly different colour while a smaller strip of paper is directly opposite the focuser laying inside the tube and under the secondary mirror. You then take a picture and use a small fine scale ruler to determine that the secondary mirror is centred in the focuser.

    Very clever. Much appreciated. Thank you!

  • took me days to realise that a cheshire isnt a laser collimator, and that the cheshire practiacally has an advanced collimation cap on it. after i collimated correctly i got 10 times better views.

  • Thank you for posting this video. You explained the collimating process for a Newtonian telescope very well.

  • What a cop out. All us cheap skates are here because we don't want to spend any money. Props for being the first Murican to say Cheshire properly.

  • hi hi can you help to me?
    I have an 8-inch dobson, you would know what the minimum focus distance on the ground is; I am new to this wonderful subject
    model skywatcher 200/1200 thanks thanks from spain

  • The red dot is in the good spot but I still see the secondairy mirror when I look at a star.

    Please help me..

  • I can't find the proper size of allen key. I have a 130/900 newtonian reflector and the nods of the secondary mirror are quite small. Does anybody have the same telescope or actually know what kind of allen key to use????

  • But how do you make sure your laser is collimated? if the beam is a few degrees off of the body, itll project a false path

  • What happened to the gap between the top portion and bottom of scope, isn't that usually just open space.

  • I have spent hours trying to collimate my Skywater Classic 200p telescope and have made zero progress. I followed your steps where you have to insert paper inside the telescope to centre the secondary mirror, which I did but when I remove the paper I can barely see the primary mirror! The only way for me to see the primary mirror more clearly is to adjust the secondary telescope again, but that means it won't be centred so I end up in this loop and can't do anything. I'm trying to follow the steps on this website: https://www.skyandtelescope.com/astronomy-resources/how-to-align-your-newtonian-reflector-telescope/ but can only do step 1 of 3. On the website, step 2 is aiming the eyepiece at the centre of the primary mirror and to do that it says I have to adjust the secondary mirror adjusting the screws. However when I adjust the outer screws, it can only do so much and I still can't get all of the primary mirror in sight. Plus I can only use the centre screw if I loosen all the outer screws first, which brings me back to my point that I can't centre the focuser with the secondary mirror. I've also tried messing around with the screws that adjust the primary mirror but I can barely see a difference. Please help I'm all out of ideas.

  • Good! My english is to simple for your explanings but you are all what you explain also showing in practice, so it's good to understand. Please show also a complete adjustment that is needed after demontage/montage.

  • I think there is a missing step. After the primary is aligned you want to tighten all the small screws on the end again, right?

  • WOW I have never collimated before but the other collimation video is way less complicated. No measuring ect..ect. but maybe you are right and the more precise the better I guess.

  • I have a question that is the name of that telescope how much you paid look nice ..what you see thru that telescope the is not normal

  • If you're looking for a laser collimation tool I highly recommend the model made by Baader planetarium. It costs a bit more than other laser collimators but it is a superior tool, well worth the money.

  • Muy buena explicación. Las instrucciones escritas siempre me confundieron, voy a poner en su punto a mi telescopio. ¡Gracias!

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