Newbie here with Celestron Astromaster 130EQ

[Clairelm1]

Hi, I am just wondering if anyone familiar with this model knows if the secondary mirror should be quite loose? I put it into the correct position but it easily moves and doesn't feel tight on the screw threads. If the tube is moved/knocked then the secondary mirror will slip so its not in a perfect position.

 

Thanks in advance for any help. I'm yet to use the scope as it's been cloudy this week, but excited to get started.

[Ricochet]

Hi Claire, the secondary should not be loose on any telescope. There are four screws on the secondary spider that you will need to adjust so that it does not move and stays in the right position. The three outer screws push down on the secondary and set the angle while the central screw pulls it tight against the other three screws and sets the "height". Your scope will definitely be out of collimation with the loose secondary so I suggest that you read through Astrobaby's collimation guide in order to understand what needs doing.

If you bought it from a local specialist telescope shop they might offer collimation for their customers.

[Clairelm1]

Thank you for your reply. It wasn't bought locally so I will have a look at the video.

Many thanks

[Clairelm1]

OK, secondary is tight now and central. I did not do primary alignment, as I don't have a collimator. I guess I will only know if it is right when I come to star test, is that right?

[Ricochet]

I imagine it will be a long way out but I wouldn't worry about it tonight. 

[Louis D]

Order a Rigel Aline Collimation Cap and you'll be able to do a very good job of aligning your primary as long as it is center marked.

[Clairelm1]

11 hours ago, Louis D said:

Order a Rigel Aline Collimation Cap and you'll be able to do a very good job of aligning your primary as long as it is center marked.

I will order this now, anything else I could need as a newbie from this site before I order do you think?

[Ricochet]

I also use one of these for collimation: https://www.firstlightoptics.com/other-collimation-tools/premium-cheshire-collimating-eyepiece.html

Of course both collimation tools assume the primary mirror has a ring marking the centre and I'm not sure if the astromasters do. 

As for other things you "need" perhaps a barlow and/or high power eyepiece as the supplied eyepieces only give you 32.5x and 65x but then things are getting more expensive and you probably should take more time to make such a decision. 

[ronin]

If you have one around an old 35mm film canister with a hole drilled centrally will get you going in order to check basic collimation.

Collimation is getting all the axis aligned and orthogonal, it is a mechanical setting up of everything so do not get too hung up on what you necessarily see. I sometimes suspect that if get it all aligned you see X, but if you see X that does not necessarily mean it is all aligned. Best at this time to set it all up as best you can by eye and maybe with whatever you have.

Eventually you will want better or more eyepieces, when you ask, if you ask, give an idea of budget. Gets too easy for suggestions like buy Delos or Naglers at £250-300 each but the scope is £135 so an eyepiece at double the scope cost seems irrelevant.

When you head off to look spend a couple of hours scribbling down things to look at, and the constellation they are in. There are a few decent globular clusters around at present, M3, M5, M13, M92, M15.

Double stasrs: Albireo, Almaak, Mizar+Alcor and the double double in Lyra - you should split this into 2 but not sure about all 4.

One thing is:- Learn the bsic constellations.

Saturn and Mars are visible but these are low so you will not get a good image of either. Expect Mars to always be a small red disk, Saturn needs about 120x to get anything from it (5mm or 6mm eyepiece).

An easy open cluster is the Double cluster in Perseus (find first with binoculars). Pleiades re better but they are not visible yet.

Possibly look for a club: http://www.astronomyclubs.co.uk/

 

[Charic]

15 hours ago, Clairelm1 said:

OK, secondary is tight now and central. I did not do primary alignment, as I don't have a collimator. I guess I will only know if it is right when I come to star test, is that right?

You do!...you just don't realize it yet?

There is a link to buy a cap above, but your scope has a dust cap right! Its the one that fits in the eyepiece, it just needs a small 1-2mm hole in its centre. This helps to align your eye to the focal axis of the scope, that's all they do! and a small white insert, white card is fine, with a hole, just slightly bigger! Then follow the instructions from page 27 here........http://www.celestron.com/media/795802/1219957574_astromasterinst.pdf

As long as the secondary mirror looks circular ( not elliptical ) and is  equally spaced all around,  ie. it looks  central when you look down the focuser tube. ( If you had a  cardboard toilet roll tube, and look through it at a coin on a flat surface,  that coin should look  circular, central and concentric [ an equal spacing around it with reference to the edge of the toilet roll ] this is the effect, level of accuracy you need with the secondary mirror, move slightly to one side and the gap between the coin edge and the tube narrows, its out of alignment? this is the reason why the 1mm hole is required in the cap, it helps to align your eye to the axis of the optical  focal train )

Not sure, but I expect your primary mirror does NOT have a central spot, a circular donut ? If this is the case, just follow the instructions from the manual. My Celestron 127 PS is of similar design to your scope, but mine is a short tube version!,  It has  NO central donut, therefore does not need any fancy or special tools or laser to collimate, just visual alignment is all that's required.

When everything is done and settled away, you could stick a plaster over that 1-2mm hole in the dust cap, if you think the dust might get in? or if you have some old photographs lying around, especially the old 35mm film canister, cut off the base of the canister, drill  a 1mm in the lid, put the two back together and there is another method for applying a collimation cap.

[Clairelm1]

Wow super helpful guys thank you. I will take a shot at the primary later.

I got an eyepiece and filter set, also by celestron, with this i got:

• 15 mm Kellner Eyepiece - 1.25”
• 6 mm Plossl Eyepiece - 1.25”
• 2X Barlow Lens with T-threads - 1.25”
• #80A Blue Filter - 1.25”
• #25 Red Filter - 1.25”
• Moon Filter - 1.25”

plus the 10mm and 20mm eyepieces which came with the scope, so i guess I've got a lot to learn with all of this. 

Is there a decent budget binocular, say £40ish you'd recommend?

[Alan64]

2 hours ago, Clairelm1 said:

I will order this now, anything else I could need as a newbie from this site before I order do you think?

Congratulations upon your purchase of a traditional Newtonian.  It is a 130mm f/5, with a focal-length of 650mm, and therefore quite versatile in observing the gamut.  Magnifications ranging from 20x, and binocular-like, to over 200x and beyond with the aid of a 2x barlow on better nights of seeing are possible.

The light path through a Newtonian takes the shape of an "L"...

The straight column of incoming celestial light strikes the primary mirror at the back which forms the light into a cone, and with its "parabolic" or bowl-shaped surface.  The light cone then strikes the secondary mirror which in turn bends the tip of the cone to the side, out through the eyepiece, and into the eye and mind of the observer. 

In collimating, the goal is simple.  The center of the primary mirror must aim directly at the center of the secondary mirror, then the center of the secondary mirror must aim directly into the center of the focusser.

The secondary mirror is mounted at a 45° angle, and is oval in shape, as shown here from my 150mm " f/5...

It's the secondary mirror that tends to give people trouble, but a better understanding of its nature can be most helpful.  Even though the secondary mirror is oval, it appears round as one looks straight down into the focusser, and also as the primary mirror "sees" it from the opposite direction, as illustrated by this secondary-spider assembly from my 200mm f/5...

In addition, the optically-flat surface of the secondary mirror must be rotated into its correct position, and with its narrower axis parallel to the bottom of the focusser...

...and the narrower axis parallel to the primary mirror as well.

The longer axis is at a 45° angle...

 

Note the "doughnut" in the center of this primary mirror...

Such helps with collimating.  Unfortunately, I don't believe that yours is center-dotted.  In any event, when you insert the collimation-cap into the focusser, and in place of the eyepiece, then point the telescope towards a blue sky or an indoor wall that's brightly-lit, this is what you may see when looking into the cap's pinhole, and of an f/5 Newtonian's optical system that is perfectly collimated...

 

This is what you're seeing, as exhibited by the same Newtonian that has been slightly thrown out of collimation, and in order to illustrate the various aspects of the scene...

1. The pinhole of the collimation-cap, and with a camera on the other side snapping the shot of the scene.

2. The primary mirror's "doughnut", or center-dot

3. The reflective surface on the underside of the collimation-cap

4. The secondary mirror, its silhouette

5. The secondary assembly's spider-vanes

6. The primary mirror

7. The primary mirror's clips, which hold the mirror in place

8. The interior of the focusser's drawtube

Then, the system is recollimated, and back to the way it was...

 

I hope this helps.  If it doesn't, feel free to reply and give me a right good thrashing.