Camera Lens Solar Filter

Perhaps you were like me during the solar eclipse last week.

I had grand plans of having my camera set up and automatically take pictures during the phenomena while I sat back with my family and basked in the shade of the moon (we were not in the path of … but we got about 80% coverage). Well, unfortunately I did not have the time or focus to make this happen, so ended up relying on an extra pair of solar glasses and my cell phone, which predictability, resulted in unremarkable images of the sun… So, I’ve decided to prep for the next sun event (eclipse, flares, spots, whatever might require a direct look at the sun) by creating my own solar filter for my own camera.

I had previously order solar filter paper after waiting too
long to order a lens filter, all in my price range were sold out. The night after the eclipse, I built a camera lens solar filter and wanted to share with all of you good people.

Please be sure to never EVER look directly into the sun (especially with a camera) and recognize that you alone are taking responsibility for constructing your own lens filter. Mine works well for me, so be sure you take the appropriate steps to protect your eyes. Let’s get started!

1. camera and lens that you will use during solar events

2. protractor / compass

3. pencil / pen

3. clean cardboard (enough for 3 layers)

4. solar filter paper (see the link for approved solar filter distributors: https://eclipse.aas.org/resources/solar-filters ) - READ THE INSTRUCTIONS THAT COME WITH THE FILTER.

5. duct tape or other that will stick to cardboard (I used electrical for first applications, duct tape for final)

6. sun

Find out the diameter of your lens. I used my 67mm lens, which means the outside ring is just shy of 71mm (7cm).

Now that you know the diameter or your lens, you will create 3 circles on your cardboard, about 1 inch apart. Use a protractor or compass. Tracing around the camera lens will result in a circle that is too large.

After you've traced your circles on the cardboard, cut the circles out. I used a combination of razor blade and scissors (you can see from my pictures, my circles aren't perfect).

Test the size of the hole on your camera lens. You want it to be very snug around the first ring of your camera. Once you've gotten the holes so that each is a snug fit on the first ring of your lens, you can cut each of your cardboard pieces to the same size (I did squares).

The next step is to cut out the solar filter paper. DO NOT get your fingers all over the paper, just the edges where you're not going to be looking through is okay. Lay the paper on a flat surface that won't scratch the filter paper (like the cardboard that the paper was shipped in) and place a square of your cutout cardboard on top. The entire square is the size that you will cut your filter paper to (NOT cutting to the circumference of your cut out will keep any sneaky sunlight from getting to your eye - especially if your circle cut outs aren't perfectly round).

Once you have cut your solar filter paper to size, you want to place it between 2 pieces of cardboard (if you read the instructions for the solar filter paper (which I hope you did), it states that the silver faces the sun. First tape the paper edges to one piece of the cardboard, and then place the second piece and tape.

Next, you will add the 3rd piece of cardboard to the cardboard piece facing the back. This 3rd piece adds enough depth to the filter that the solar filter will lay directly against the camera lens without pushing against it or causing a ripple in the filter.

Check it for fit on your camera, making sure it is snug on the outside ring, allowing you full lens mobility (unlike filters you purchase, where the filter is placed on a set up camera and taped to the lens, removing the ability to change anything on the lens). The final construction step, add duct tape to seal everything up. I dug into my daughter's stash of science experiment materials and found pink.

Taking pictures of the sun is fun and interesting - just be safe and enjoy the next eclipse... partial, annular, or total or other sun event. Keep your filter stored in a safe place where the paper won't get scratched as this will degrade the paper and make it unusable. Use something like a hard box or envelope.

Here are some solar viewing tips for staying safe:

https://www.sciencefriday.com/educational-resource...