Make a Safe Sun Projector Using Binoculars
Make a safe Sun projector to watch solar eclipses with a pair of binoculars or a telescope.
Next Annular Solar Eclipse: Sun, Jun 21, 2020 … See animation
Project the Sun
Never look directly at the Sun without proper eye protection. You can seriously hurt your eyes and even go blind.
Some Lenses Safer Than Others
While projection is the cheapest and one of the safest ways of viewing a solar eclipse, the direct heat of the Sun can potentially harm binocular and telescope eyepieces, particularly the more complex ones that use a specific kind of glue or cement to adhere multiple lenses and prisms together. The heat can melt the cement and damage the lenses. Because of this, astronomers and Sun-watching enthusiasts suggest using simple lenses such as the Huygens and Ramsden eyepieces when using telescopes and binoculars to project a solar eclipse.
DIY Projector with Binoculars
With a quickly assembled projector using binoculars or a telescope, it's easier to create bigger and sharper eclipse projections than with a simple pinhole projector. It applies the same concept as a pinhole projector, but the Sun's image is projected through a magnifying lens instead of a pinhole.
- binoculars or a telescope
- a tripod
- duct tape
- a sheet of white paper
What to Do:
- Put the binoculars or the telescope on the tripod. Use duct tape to make sure that it is steady.
- Trace the lenses of the telescope or binoculars on the cardboard, and cut out the holes.
- Tape the cardboard in front of the binoculars or the telescope so that the lenses stick out of the holes.
- If there are any holes or spaces between the cardboard sheet and the lenses, cover them with duct tape.
- Direct the binoculars toward the Sun without looking at the Sun directly.
- Place the sheet of the paper on the ground at a distance below the eyepiece.
- Move the paper around until you see the Sun's image projected on the paper.
- Never look at the Sun directly without protective eye gear. Even sunglasses cannot protect your eyes from the damage the Sun's rays can do to them.
- Always consult the manual of your binoculars or telescope. Internal heat build-up can damage the telescope and any accessories attached to it.
- Do not look at the Sun through the binoculars or the telescope.
- Always keep your back toward the Sun while looking at a projection.
- Only use your projector for a few minutes at a time. The Sun's rays heat both the binoculars and create a possibly flammable hot spot on the paper.
- Don't leave your projector unattended.