Can A Telescope Be Used Through A Window?

Can A Telescope Be Used Through A Window

I have often heard beginner stargazers asking if they can use telescopes through a window. Now I know, that can be a dumb question, but those who are just starting out can get confused over this. So, I decided to tackle that confusion in this article.

Can a telescope be used through a window? No, you can’t. Window glasses are not made for optical viewing purposes. They can seriously distort images and lower down the quality. That’s why it is never recommended to use any optical devices through a window.

 Why Can’t You Use A Telescope Through A Window?

There are many reasons for that. But two of them stand out the most. Here are the main reasons why you can’t use a telescope through a window:

  1. The glass used in the telescope and the glass used in windows is not same at all. There are vast differences in terms of quality. Window glasses are nowhere near in quality as optical glasses (used in telescopes, Finderscopes, binoculars, etc.). That’s why, window glass can seriously distort the light coming through it and produce a very low-quality image. As a result, no matter how expensive or good your telescope is, you’ll always get a poor quality image.
  2. No matter where you live, there will always be a temperature difference between your room and the outside environment. We know that air flows from a warmer environment to a cooler environment. So, if you set your telescope beside a window, you can face a nasty air current coming from outside to your room. This air current can cause serious distortion to your telescope image.

Isn’t There Any Way To Use Telescope Through Window?

As I have already told before, it is not recommended at all to use a telescope through a window. However, if you must, you can. But, the image quality will get degraded. That’s the sacrifice you’ll have to make.

  • First, you’ll have to close the window.
  • Set your telescope beside the window. Keep everything ready and make sure your telescope is perfectly set up for viewing.
  • Remember, as you are viewing through a closed window, the window itself will now act as a lens. As the window glass has poorer quality compared to the lens used in the telescope, the window glass will ultimately determine the final quality of the image.
  • Now you need to point the telescope directly towards the object you want to observe. Many stargazers make the mistake of pointing the telescope at an angle. Pointing the scope at an angle can produce a further distorted image than pointing straight.

This is how you can use a telescope through a window. However, I’ll always recommend to set your telescope in an open place and enjoy the night sky from there. If you are new at stargazing, I’ll highly urge you to go through an article I’ve written on telescope tips for beginners. It’ll surely help you a lot.

Final Words

So, I hope by now you know why you can’t use a telescope through a window. If you are a beginner and want to know more about using telescopes, read my other posts on the site.



I have wondered how the Stars and Moons look like for many years. I’ve fallen in love with Cosmology since I was a boy. I am writing these articles to share my love for astronomy with you.

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