.......... HOW I FILMED VENUS WITH My iPhone............
Ever want to video a Planet against a Sun indoors ?
This will show you how
And throw in a partial eclipse too !
Step 1: GET INSIDE a BOX CAMERA
You need to Fully Darken a Room, by using metal aluminum foil ( kitchen foil ) in the window glass facing the Sun and good shades on the other non-sun side windows.
In preparation to a stellar Sun event like, a Sun eclipse by our Moon or 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 pin-hole.. 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 pin-hole 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 my Box_Camera the screen was about eight feet from the Pin-Hole and almost on the floor for the 2012 Venus transit as the the Sun was setting in the West.. Bare in mind that the further away the Screen is from the Pin-Hole the bigger and dimmer it is but you can increase the Pin-Holediameter within limits.
Step 2: MAKING THE PIN-HOLE Frame
I made my Pin-Hole Frame 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 Pin-Hole Frame over a cut out in the foiled window..
- You can see a small square cut out in the foil under glass where the actual Pin-Hole frame is placed ( last picture ).
If you need to relocate the Pin-Hole.. Just prepare a new 2" by 2" cut out and move the frame.. Then simply place a foil scrap over the exposed square.
Step 3: SITE PREPARATION
As site preparation, all you need to do is remove any obstacles between your Pin-Hole and that Sun 93,000,000 miles away.
A case in point is the Power Line wires in the Street that show in the video.
I could NOT do anything about the Power Lines. But I did remove a tree branch that was in the way.
That is one of the reasons telescopes are constructed on hills and mountain tops !
Step 4: HOW IT WORKS
You can make a pin hole with your own hand to magnify a small print in a recipe or legal small print !
A Pin-HoleBOX_CAMERA can be any size
From a simple Shoe Box_Camera all the way up to a Walk in Room BIG BOX_CAMERA !
The Pin-Hole is basically a High f-stop, focused to infinity, semi Fish-Eye inverting lens..
Wow what does that mean ?
- Well first there is NO Lens only a sharp 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.
Step 5: SOLAR FUTURE to PINHOLE WATCH
You can get an Apple app for your iPhone to track Eclipse events coming up.
2019 Solar Transits
When Mercury transits the Sun, you can see it as a tiny black dot
silhouetted against the Sun's disk. The next time is on November 11/12, 2019
Eclipses this Year
Jul 13, 2018 – Partial Solar Eclipse This summer
Aug 11, 2018 – Partial Solar Eclipse And this Fall
Good Luck :-)