First, the obligatory warning:
Never look directly at the partially eclipsed sun!
Later this month I will be traveling some distance to observe the total solar eclipse. I have been waiting a long time for this opportunity. It occurred to me that I would like to photograph the eclipse with my phone and maybe share the photos. I tried simply putting a filter over the lens of my phone; but, when I held the phone up anywhere near the sun I was painfully blinded. And the resulting image of the sun was very small. So, I set about building a solution.
First, I ordered an inexpensive telephoto lens ($32) for my phone to make the image larger.
And I needed something to shield my eyes from the sun. This is what I came up with.
I started with a 9″ x 11″ board, 3/4″ thick. These dimensions aren’t critical, but you’ll want it large enough to cover the brightest area of the sky when held at arm’s length. A thinner board would be lighter to hold, but I needed it thick enough to hold a screw and this one was in my “scraps & pieces” bin.
I needed a hole for the lens. I centered the phone in the board and marked where the camera lens fell. The lens was 1-1/8 inches in diameter so I drilled a 1-1/4 inch hole for it. The lens comes with a phone case that holds the telephoto lens in place over the phone’s camera lens; it also comes with a mounting ring that I affixed to the board with 3 screws.
To attenuate the sunlight, I used the filter from a pair of paper eclipse glasses. I cut the filter to fit inside the phone case. It fits between the phone and the phone case, covering the lens opening. By taping the filter inside the case, the phone can be used normally and then inserted into the rig when needed.
I tried out this rig and it worked just as I wanted. And I thought that I was finished. But after using the rig for a few minutes, I realized that there was no way to set it down without it resting on either the lens or the face of the phone. That’s when I added the second small board (4″ x 5″ x 3/4″) to act as both a sun shield and a kickstand. I attached the small board to the base using wood glue. I thought about adding a screw, or two, but the glue is surely strong enough… and, after all, I am only going to use this rig one time.
Note: Before you tighten the thumbscrew that holds the lens in the ring, there is some play that allows the lens to shift around. It is important that as you tighten the thumbscrew, the phone case is flat against the board and that there is no strain on the case. If the lens is not perpendicular to the case/phone the image of the sun will not be round.
Upon more experimentation, I found that I get better pictures if I disable the auto-exposure and auto-focus on my phone and manually turn the exposure all the way down. I have an iPhone 5s – your experience or your phone may be different. There are many sites on the web which can tell you how to do this with your phone. Note: Combining the telephoto lens and max digital zoom completely filled the frame with the image of the sun, but made it difficult to get the sun into the frame and keep it there. After several tries I decided to use less than max digital zoom.
Also I should probably mention that you can take serviceable photos without the telephoto lens. Just put the filter over your phone’s lens and turn the digital zoom all the way up. I have included some photos so you can compare the results. You will still need some sort of sun shield around your phone.
Also some readers said they thought that the filter should go on the front of the telephoto lens instead of between it and the phone; so, I tried it and you can compare the results. It was hardly a controlled experiment – the sun kept going behind clouds – but in front of the telephoto lens is probably better. For the tests, I simply glued the filter to the front of the lens with a glue stick. For a more rugged solution I would probably use some rubber cement or similar. Epoxy and super glue would be too difficult to remove.
You could cut a hole in the lens cap and glue the filter in there – I’ve already lost mine.
2. Yarrashop iPhone Camera Lens Kit, 12x Telephoto (Amazon,$32)
3. paper eclipse glasses
4. wood board, 9″ x 11″ x 3/4″
5. wood board, 4″ x 5″ x 3/4″
6. 3 self-drilling, truss head, lath screws, 1″ x #8
7. wood glue
8. adhesive tape