Question about Celestron NexStar 130SLT (31145) (306 x 130mm) Telescope

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I used the collimation eyepiece to collimate my telescope.But I dont know if it's properly aligned. The knobs on the bottom of the tube are turned fully clockwise, and the black dot in the eyepiece is directly in the middle.But I do see some lines on the outer portion of the mirror.I dont know if I've lined up the primary mirror with the second properly.Im confused on how to do it.

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Before you do anything else, take the scope outside on a good night, find a semi- bright star (Polaris will do). Let the scope cool down! (about 45 minutes) use your highest power eyepiece and put the star in focus.
Now take the star out of focus (inner focus or outer focus) you should see a dark circle in the center with symmetrical rings around it (airy rings). If the dark circle is in the center and the airy rings are symmetrical, your telescope is collimated
Check both inner and outer focus, they should be close to the same. If not you should re-collimate.
Best done with fainter stars but for now stick to the brighter ones.
Because I own 3 scopes, I use a Hotech laser collimator. its quick and easy. Worth it if you travel with your scopes to dark sites

A good guide on how to collimate
http://www.skyandtelescope.com/howto/diy/3306876.html

Posted on Oct 18, 2010

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I have a T1000HD telescope . I was wondering what I need to do to be able to see planets such as Mars, Jupiter and Saturn's rings. Is it just a matter of getting different eyepieces? If so what kind?


That scope came with a 25 mm and a 10 mm eyepiece, which will give about a x40 and a x100 magnification respectively. If the seeing is good (clear sky, not dusty or windy, and the planet not too low (at least 30 deg up from the horizon) you should get a reasonable view of the planets, with these ep's

If you do not have any ep's you could buy 2 or 3 plossl type ep's (nothing more expensive is justified) of say 10 mm, 25 mm, and 32 mm. It looks like it takes ep's with a 1.25" barrel.

The theoretical limiting power of your scope is about x 220, which is about a 4 mm eyepiece, but at that extreme you will find the viewing object is dim, fuzzy, hard to get into the field of view, hard to focus, and totally frustrating.

Sadly this scope is just not a very good one, sorry to sound elitist. One of the issues will be that of collimation (optical alignment). You can never properly focus the scope unless it is collimated. Reflector scopes (with a mirror) all have this difficulty. You can tell if it is collimated with a star test

http://garyseronik.com/no-tools-telescope-collimation/

There should be 3 screws on the bottom end of the scope, where the mirror is. These are the collimation screws. Have somebody screw these in and out while you look through the ep. Remember you can only assess the collimation when the defocussed star image is right in the middle of your view.
.

Dec 12, 2016 | Optics

1 Answer

How do i set up eye pieces and focus lenses?? Instruction manual came in chinese with no translation and we are begiiners!


During the day:
1. Point to a far (1000 meters or more) object
2. Insert the lowest power (highest number) eyepiece e.g. 25mm
3. focus on the object.
4. Align finder to match what you see in the scope.
At night.
1. Put scope out and let it reach the temperature of the outside.
2. Point finder to the moon (1st object you should always use to check scope and finder alignment)
3. Use the same low power eyepiece.
4. If everything seems fine, switch to a higher power eyepiece and enjoy the view. You may have to slightly adjust the finder to align with the main scope.
If the views are blurry, the telescope may be out of collimation. Look on the internet for generic collimation instructions.
If this still did not help. Throw the scope out! Its probably a piece of junk and will only discourage you.

Dec 12, 2012 | Optics

1 Answer

I can't get my Meade 10" Lightbridge telescope to focus in the eyepiece. I bought a Meade Laser Collimator and Collimated it last night outside before I tried to observe Jupiter and it still didn't...


Even if the scope is a little out of collimation it should still focus. Put the eyepiece with the largest number written on it into the focuser. DO NOT use a 2x barlow if you have one.

Try again--- you can do this during the day time on a distant object and practice turning the focus knob slowly left and or right until you get a sharp image.

The higher the magnification the smaller the "sweet spot" with the focuser.

Jan 13, 2011 | Meade LightBridge 10 in. Standard (600 x...

2 Answers

Celestron PowerSeeker 114AZ Telescope model 21056-K . . . we have collimated it but still cannot sight anything. Just black .... ideas?


Hi, I have the same telescope and also the same problem. Don't know if the black thing on the front of the telescope should be remove.

Dec 26, 2010 | Celestron PowerSeeker 114 EQ Telescope

1 Answer

I have a Swift short tube catadioptic equitorial reflector telescope Model # 856. It hasn't been usable since it was moved to a new location. It may be the mirror, I don't know. Who repairs these...


This is a small reflector style telescope on an EQ mount.

1. The mount must be polar aligned to Polaris

2. The scope may need to be collimated

Read my Equatorial mount TIP on my profile page that explains how to polar align.

and watch this video that explains collimation:

http://www.andysshotglass.com/Collimating.html

Mar 13, 2010 | Swift Optics

1 Answer

SO......102MM ASTRO-NOVA TELESCOPE.SHOULD I OPEN THE BACK[BLACK PLASTIC] OR THE FRONT[METALLLIC WHITE]? THANKS..


The front is the part where the eyepiece and the focuser happens to be. That is called a REFLECTOR style telescope. Light enters the front of the tube and bounces off the mirror in the bottom of the tube. There returns and bounces off the small secondary tilted mirror out into the focuser and eyepiece. There should be an easy to remove dust cap on the front end near the focuser. That end is pointed toward the sky.

These types of scopes should be checked for collimation to determine if the optics are all lined up.

Watch this video:

http://www.andysshotglass.com/Collimating.html

Try to find a local Astronomy club and get them to help you with the telescope.

Nov 14, 2009 | Edu-Science (10166) Telescope

4 Answers

Can't focus my telescope


If there is nothing on the objective lenses or eyepiece lenses then it most likely needs collimation. This is where you adjust the secondary mirror while viewing an out of focus star. You need stable sky conditions to do this.

There are most likely three small screws at the front of the telescope and these are what you use to adjust it. As one screw is loosened then another is tightened. Do this in very small increments. If you have your manual it should outline how to perform this. If not go to this web site: http://www.astrosurf.com/legault/collim.html. It will show examples of how objects look both in and out of collimation. There is a section further down the page for SCTs.

A very handy tool for this is to replace your screws with Bob's Knobs (http://www.bobsknobs.com/) . These replace the screws and allow you to adjust it by hand instead of a screwdriver.

The other focusing problem I've experience with my Celestron SCT is to have the focus knob loosen up and then slip as I turned it so that I could never focus with it.

Good luck and clear skies!

-jodair

Mar 29, 2009 | Meade Optics

1 Answer

Lost vision


Your telescope is a "Newtonian," as such it requires regular "collimation" Collimation the alignment of the optics. The mirrors must be lined up properly for the telescope to deliver a good image to the eyepiece. Your scope sound like it is way out of collimation. My guess is that the diagonal (secondary) mirror has rotated in it's mount. There are three basic tools for collimating a Newtonian the Sight Tube, Cheshire and Autocollimator. To get your digonal aligned correctly you need a sight tube. Rather than spend a lot on these consider making your own and keep an eye on eBay offerings. Don't bother investing in a laser collimator, they simply don't do the job unless you go for the very best. From some help with the collimation process check these links.
http://www.astronexus.com/node/6
http://www.amateurastronomy.com/collimate.html
The 60 page pamphlet "New Perspectives on Newtonian Collimation," Fourth Edition by Vic Menard and Tippy D’Auria runs $10, but if you really want to do it right it's worth the money.
HTH, George

Feb 24, 2008 | Bushnell Deep Space 78-9518 (675 x 114mm)...

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