You are living the life that people actually want to become engineers for: changing lives, letting people see something from another perspective (in this case, literally) and inspiring the next generation. Everytime I come to your channel to see a new video, I never leave disappointed or uninterested.

Great job Grady. To improve image contrast you can spray the inside of your funnel matt black. This reduces internal reflection of light scattered back from the projection screen being reflected around the tube and lightening up the darker areas of the projected image. Should make sun spots stand out much more clearly.

First! Want a Practical Engineering t-shirt? They're soooo soft!

Like you, I will also be SLIGHTLY out of the path of totality. We'll only be seeing 99.9% of the eclipse. I will also be at the elementary school where I teach science. I can't just abandon 400 kids to get a better view. Our school has a device called a SunSpotter which works a lot like what you've built. When you get it lined up, it projects a larger and dimmer image of the sun onto a white stage that is part of the device. I've used it over the years to show kids sunspots and to demonstrate the slow rotation of the Earth (as the sun visably moves over the plate), but it'll be an interesting and safe way for us to view our (almost) total eclipse. Meanwhile, I'm already making plans to be in totality when the April, 2024 eclipse crosses the US. I'm not going to miss that one!

Wow, the quality of the projection is so good that you can easily identify the sun spots :D

That's so funny, I happened to try this for my own for the first time just this afternoon! It worked great and I saw those exact sunspots as are in the video

Love learning with you guys!!!

Really do enjoy your videos mate. Thanks for sharing your knowledge in such a clear and engaging way.

It so cool how you can even see the sun spots!

At the last eclipse I built myself a camera obscura from our office pantry because a) I was at work, b) I don't have neither a telescope nor c) those special sun glasses (I forgot where I put them after the eclipse of 1999). I covered the whole window with paper to get it dark inside and punched a hole with a pin in it. I just had to hold a screen into the light beam. But you need at least card board to get it really dark. Otherwise the tiny amount of light getting through the pin hole does not make a clear picture. If the hole is too big the picture is blurry (out of focus).

Awesome solution! Best regards from São Paulo, Brasil

My son and I set up a pinhole camera affixed at a specific height over our backyard picnic table, and aimed to shine down at a paper tablet. During the actual event, every five minutes, he documented the time and the shape the pinhole camera cast upon the page. Not only did we effectively document the progression of the eclipse itself, but also the path of the light's trajectory as the earth rotated.

just made one! it's amazing! one note, though, we found it was much easier to use a rubber band to hold the screen on the end of the funnel than a hose clamp (we used shower curtain liner as the screen material). anyway, what a cool project! thanks!

Well, you shot this recently. I recognize that sunspot as being a total PITA to get into perfect focus with my old camera.

Thanks for the cool video Grady. I just tossed out my aging telescope, now I'm kicking myself!!!

Love the channel!!!

Cool build!

Awesome stuff

you should really paint the inside of the cone black. to prevent the internal back reflection from the screen that then saturates the borders of the screen.

Can you get similar (smaller projection) without a telescope. Maybe with a pin hole at the eye piece end?