Science Buddies: "Ask an Expert"

Posted on behalf of teacher
https://www.sciencebuddies.org/stem-act ... -telescope

-------------------------------------
Dear Science Buddies,
I recently watched your YouTube video on how to make a refracting telescope and decided to try the project with my 3rd grade class.

We first purchased the lenses you suggested, and they all appeared to be convex lenses. When we assembled the telescope, we were able to see an image, but it was upside down. The other two 3rd grade classes went ahead and completed their telescopes this way. From what I understand, that setup is actually similar to what Galileo used and would work well for stargazing.

However, in your video, the image shown through the telescope does not appear upside down. Since we were hoping to replicate the version shown in the video, I tried ordering the suggested concave lens to use as the eyepiece. With that configuration, the image appears upright, but we haven’t been able to bring it into focus, no matter how we adjust the distance between the lenses.

Could you clarify whether the telescope in your video uses a different combination of lenses or an additional lens to achieve an upright, focused image? We’ve experimented with adjusting the spacing, but we’re still unable to get a clear result.

Our class is very excited about completing this project, and I would greatly appreciate any guidance you can provide.

Thank you so much for your time and for sharing such a helpful resource for educators.

Best regards,
--
Tonja

Hi Tonja,

Thanks for contacting us! Yes, the telescope in the video was made with the two lenses linked from the materials section of the written instructions:

https://www.homesciencetools.com/produc ... l/?aff=SB1

https://www.homesciencetools.com/produc ... l/?aff=SB1

If you still have the boxes, can you check to make 100% sure you received the right lenses? The packaging should be labeled, as shown around the 10 second mark in the video.

I just double checked with my telescope (I still have the blue and orange one from the pictures in the written instructions, I can't find the green and pink one from the video - probably thanks to my own kids), and I'm able to focus on objects both across the room and out my window, when the lenses are approximately one foot apart. Can you clarify how far away the objects your students are trying to view are? If they're too close, they probably won't be able to focus.

Thanks,

Ben Finio, PhD
Lead Staff Scientist
Science Buddies