Mastering Telescope Collimation: Tips and Tricks for Perfect Alignment

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In summary, the speaker recently purchased a 130 mm reflecting telescope and has been struggling to collimate it due to the mirrors being out of alignment. They have tried using a laser collimating tool but found it to be ineffective. They are seeking suggestions and have been advised to use a star test collimation method. The process involves viewing a star out of focus and adjusting until the outer and inner rings of the doughnut are concentric, then focusing the star and adjusting until concentric circles are seen. The speaker has been referred to a helpful guide on collimation.
  • #1
Drakkith
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Hello! I purchased a 130 mm reflecting telescope a few months ago. I recently have had to try to collimate it due to the mirrors being out of alignment, but I'm not sure I'm getting it 100% correct. I follow the directions in the instruction manual, but it seems that even when I think it's perfect it still seems to be off when I look at something through it.

I tried a laser collimating tool i purchased, but it is effectively useless. The instructions don't seem to match what I see on my scope and the dot is pretty much always in the center of the collimating tool. (WTF is a donut in reference to a telescope?)

Does anyone have some suggestions? I'm not 100% sure if the distortions I'm seeing through my scope are due to the alignment being off or because of atmospheric effects. Thanks.
 
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  • #2
I had a laser tool too and didn't like it. The best way is on a night with good seeing, using a star. Google "star test collimation". In short, though:

The process is two steps:
1. First view a star out of focus so you see a big doughnut. The outer and inner rings of the doughnut should be perfectly concentric. If not, adjust until they are.
2. Focus the star (you may need a dimmer star). You should see a point of light with concentric circles around it (diffraction rings). If not, adjust until they are.

Here's a good guide I've used: http://legault.perso.sfr.fr/collim.html
 
  • #3
Thanks, I'll look it up. Also, the donut thing was from the instructions on the Laser Collimater. It said to make sure the dot was inside the donut. It would brighten when it was on top of the donut, and dim again once it was inside the donut. No idea what they were talking about with that.
 
  • #4
Agreed, laser collimators are not user friendly. This is my favorite collimation guide:
http://www.skyandtelescope.com/howto/diy/3306876.html
 
  • #5


As a scientist and a fellow telescope enthusiast, I understand your frustration with collimation. It can be a tricky process, especially for beginners. First of all, I want to assure you that you are not alone in facing this challenge. Many telescope owners struggle with collimation, and it takes practice and patience to master it.

One tip I can offer is to make sure you are using the correct tools for collimation. While laser collimators can be helpful, they are not always accurate and can sometimes cause more confusion. I recommend using a simple collimation cap or a Cheshire eyepiece, which are specifically designed for collimating reflecting telescopes.

Additionally, it's important to understand the concept of a "donut" in reference to telescope collimation. When you look through the eyepiece of a reflecting telescope, you should see a circular reflection in the center of the eyepiece. This is known as the "donut," and it should be perfectly centered and symmetrical. If it appears off-center or distorted, then your collimation is likely off.

If you are still having trouble with collimation, it may be helpful to seek guidance from a more experienced telescope user or attend a local astronomy club meeting where you can learn hands-on techniques for collimation.

Lastly, it's important to consider atmospheric effects when viewing through a telescope. Sometimes, distortions can be caused by turbulence in the atmosphere, especially if you are viewing from a city with light pollution. However, if you have properly collimated your telescope, the distortions should be minimal.

I hope these tips and suggestions help you in your quest for perfect collimation. Remember to be patient and keep practicing, and eventually, you will master the art of collimation. Happy stargazing!
 

1. What is collimation and why is it important for telescopes?

Collimation is the process of aligning the optical elements of a telescope to ensure that light rays entering the telescope are focused to a single point. It is important for telescopes because it directly affects the quality of images produced. If a telescope is not properly collimated, the images will appear blurry and distorted.

2. How do I know if my telescope needs to be collimated?

There are a few signs that indicate a telescope may need to be collimated. These include blurry or distorted images, double images, off-center images, and difficulty focusing. If you notice any of these issues, it is a good idea to check the collimation of your telescope.

3. Can I collimate my telescope myself or do I need professional help?

Many amateur astronomers are able to successfully collimate their own telescopes with the proper tools and procedures. However, if you are not comfortable with the process or have a high-end telescope, it may be best to seek professional help to ensure the best results.

4. What tools are needed to collimate a telescope?

The tools needed to collimate a telescope vary depending on the type of telescope, but some common tools include a collimation cap or laser collimator, a Cheshire eyepiece, and a star chart or target for testing the collimation. It is important to use proper tools and follow a specific procedure for collimation.

5. How often should a telescope be collimated?

The frequency of collimation depends on various factors such as the type of telescope, how often it is used, and the conditions it is used in. A general rule of thumb is to check the collimation every few months and after any major transportation or impact to the telescope. However, if you are noticing issues with image quality, it may be necessary to collimate more frequently.

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