Ever want to video an Eclipse of the Sun indoors ?
This will show you how

Step 1: STEP INSIDE a PINHOLE BOX CAMERA

You need to Fully Darken a Room, by using metal aluminum foil ( kitchen foil ) in the window glass facing the Sun and shades on the other non-sun side windows.
In preparation to a stellar Sun event like, a Sun Eclipse by our Moon or even a Planetary transit.

There needs to be a straight line of sight, from a white screen in the room, through the window and to the Sun !

This point will be where you will tape the Pinhole.. Keeping in mind that the Sun (Earth) will move primarily vertically (up or down) during the Stellar event and your screen needs to accommodate this motion if you want to capture the entire episode.

Otherwise you may need to move the Pinhole during the stellar show !

I strongly recommend that you do a trial run of the set up a day or three before the Sun event so that you can mark the position of your screen for the full vertical episode time with only a small (left or right) shift on a daily change. Inside of my Box_Camera the screen was about 30 feet from the Pinhole and downstairs, following a previous Venus transit, as the Sun was afternoon in the West..

Step 2: MAKING the PINHOLE

I made my Pinhole with a cardboard square four inches on each side and then a 2 inch diameter hole in the center.

Then I placed the cardboard over aluminum foil ( see picture ) and bent the foil extend over the edge..

Next used a small sharp blade to precut tear lines for the 1/4" pen that would enlarge the hole to about 1/4"..

After you insert a pen or other 1/4" instrument through the foil (Do Not use a punch, it leaves a rough edge)

Make sure the hole is round and clear of fragments, then press it flat as possible without distortion.

Finally tape the foil to the cardboard to stabilize the aluminum for easy placement of the Pinhole over a cut out in the foiled window..

Step 3: SITE PREPARATION

As site preparation, all you need to do is remove any obstacles between your Pinhole and that Moon 240,000 miles from Earth with a diameter of 2159 miles, starting to block the Sun 93,000,000 miles away with a 865,000 mile diameter that's over 400 times the Moon dia !

This could mean cutting away some tree branches that would block the Sunlight.

Step 4: HOW It WORKS

TIP
If you get caught without your customary glasses, you can make a pin hole with your own hand to magnify a small print in a box top recipe or legalese small print !

A Pinhole BOX_CAMERA can be any size

https://www.timeanddate.com/eclipse/box-pinhole-p...

From a simple Shoe Box_Camera all the way up to a Walk in Room BIG BOX_CAMERA !

The Pinhole is basically a High f-stop, focus to infinity, semi Fish-Eye, inverting lens..

Wow what does that mean ?

Well first there is NO Lens only a sharp round hole ! ...

It works but you have to accept that on a Physics major's word, ( If you are a Physics major please explain it in comments for us:-)

High f-stop means you do not get much light through a Pin-Hole ( self evident )...

The Pin-Hole inverts the image just like a real lens would do or does !

The Physics of a Pin-Hole finds everything is in focus out to infinity !!

In practice I find getting to close to a subject does not make much of a picture..

Yea its in focus but what is it ?

Fish-Eye is the result of infinite focus, Just imagine you have to pull infinite 3D space into the 2D confines of two square feet or just two square centimeters . . . . Boggles the mind and does strange things up close.