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good idea, especially when looking at the sun. even without magnification.

It is a trade off. The smaller the pin hole, the better focus you get, even at long distances. the larger the hole, the brighter your image will be but it will be fuzzy and out of focus.

Simply say goodbye to your cellphone camera.

I'm glad it worked.

sorry iy didn't work out. we had intermittent clouds here but decent viewing during the sunny bits.

The binocular technique worked great for me!

For the target? The light would be absorbed and the image would be dark. Think of projector screens, they are white to reflect light back towards you.

Ok that does make sense

s. Powell Wouldn't The Binoculars Make It Brighter?

Thomas: take a look at the video. You don't look through the binocs, you project the image from the binocs onto a shaded piece of paper. The image will be magnified. You'll be able to see sun spots and the moon's shadow moving across the face of the sun.

Al Murray it's a sun simulator

sure, if you have a really, really long path to your target. The Pinhole gives me a 1/3" target at 24" distance. You can plug in the lens equation for s simple convex lens, you'll need several dozen feet. The 2nd lens on the binocs helps bring this to a manageable length.

dear the Sci Life: as a back up, I'd make some foil overlay with actual pin-sized holes. I think your 3/4" holes are way too large. It will be hard to focus the light. The idea of a camera obscura or pinhole projector is to only allow parallel light in from an object at infinity and to then focus that light on your target. More light will make for a brighter image but that light will be blurred across your target. The holes I used were from a paperclip. For small holes with a pin, a ragged edge is less likely than with larger tools as you found out. If Sunday turns out sunny, give your projectors a tryout. You can adjust the pinholes and the length of the boxes as needed. Have a blast with the kids! BTW: in the Dallas/Ft Worth area (not sure where in N Texas you are) the eclipse will be about 75%, which is better than the 68% I'll be getting here in Massachusetts. I'm making a few pinhole projectors out of mailing tubes and one eyepiece projector to take to work on Monday.

Thanks Al! Hmm I've got that feeling like we may have messed something up. The good news is we've actually made 3 different versions, one of which being a true pinhole size (well thumb tack). If you get a chance, check out our video where we tested with a phone camera light, and let me know what you think. 75% huh... that sounds promising! We thought briefly about heading up north but we've already made that drive once this summer. Will have to in 2024 :)

I saw the video, the problem with a cell phone camera, or any terrestrial light source is that the rays aren't parallel as the rays from stellar objects (starts/the sun) are. Any divergent light (flash, incandescent or LED) will not satisfy the parallel lines needed to test out a lens. the "real" pin point hole will give nice crisp image at the tradeoff of being dimmer dimmer. I used 24" (61cm) mailing tubes this year with a tiny pinhole, the image is only about .5cm across. the ratio will be about the same, to get a 1cm image, the tube will need to be 120cm long. I setup my eyepiece projector today (binocs on a tripod) and got a decent 10.5cm image. Good luck and clear skies.

Dont do it. You may think nothing happened when you're in the midst of watching, but you'll start noticing some vision damage after a few hours. Please do some research! Don't lose the opportunity of witnessing every single morning.

please don't take any risks: there are no pain receptors in the retina so you may not think you're doing damage, but you are. You can actually burn your retina. NEVER look directly at the sun.

I'll do it on Jun 21 2020

...IF you own a telescope.

Dave: Absolutely. another safe method is to purchase "eclipse glasses" but only from a reputable source. www.telescope.com/Accessories/Telescope-Eyepiece-Filters/Orion-Solar-Eclipse-Safe-Viewing-Glasses-5-Pack/c/3/sc/48/p/116532.uts or myscienceshop.com/product/gift/81037

Blue StarFractal I use white paper to see the solar disk. Black paper would not reflect very well.

Thanks Al for responding! By the way Al, I project the Sun's image using binoculars because I don't own a telescope. What I see is a pale yellow disk,especially when looking back and forth between the white paper for contrast. Is that what you see with your telescope with its higher magnification ? I won't pester you with any more questions Al!

Blue StarFractal I use my 7x35 binoculars

Then do you see what I see Al? ( pale yellow dot?) My binoculars are 7x35 too. Also,why is projecting safe? Don't UV-rays get reflected off of the paper too?

As you can see in the movie, I see a 1-2" bright white disk withe sunspots clearly defined. as I understand reflection, the light penetrates several layers of the paper, the shorter UV wavelengths penetrate more deeply and are mostly absorbed while the white light is partly absorbed and partly reflected.

Through the Telescope! Maybe there were no sunspots that day

Hi, we are entering a period of Solar Minimum so there may not be any sunspots on any given day. Check here spaceweather.com/ and look for the "Daily Sun" feature to see if there are any sunspots.

yes, there is a risk. My binocs aren't very expensive and I only point them towards the sun for a few moments at a time. There is a LOT of built up heat and glued components can easily melt.

rip them eyepieces

Sure. Anything that is sturdy but will allow you to poke a hole will do. The cardboard itself gives a ragged edge. Foil is easiest but may not be available where you live.

+Al Murray thank you very much, your video and your reply helped me so much, i'm from indonesia (the country which can see eclipse in 2016) that's why your video is very useful :^D

Dear Mega, I'm glad you found this useful How was the eclipse? -Al

+devaldy nathan NO, emphatically NO. please use indirect viewing or a certified sunsafe viewing aid

+Al Murray Oh Okay.. Thanks.. :)

+chris crous Chris, I'd be careful.. You state "tinted safety glasses. are they UV blocking? While it is generally acceptable now to use welders glasses, I'd be skeptical of any cobbled together stack of regular tinted glasses. there are Mylar sun viewing glasses but the least expensive and safest method is a simple pinhole as described in many other videos and writings. Be careful!

Glad you got to see it. Which method did you use and were you able to take any photos? If so, please let us know where you were when you took them. (sunrise is just coming up here in Massachusetts)

Al Murray well, i used the second method, only it was a much smaller cardboard. Still, the projection of the sun was very clear and enjoyable. I watched the eclipe in athens, greece,so it was a partial eclipse.

NO! Sunglasses only block a small percentage of the sunlight. Approved solar glasses block close to 99% and allow you to only see the sun. The brightness should be reduced to about what you'd see when looking at the full moon.

I don't think that would be a safe idea. 1) you'll probably damage your camera as the concentrated light will saturate and cook the CCD. 2) the camera body doesn't provide much protection from teh sun; it is easy to accidentally look past the camera and into ye sun. The methods I recommend have you looking away from the sun.

yes (i'm pretty sure)