Safe solar observing
Concentrated sunlight can permanently injure eyesight and damage equipment in a fraction of a moment. Safety must be established before an instrument is pointed toward the Sun.
Do not begin without a correctly fitted front solar filter and a check of every optical path.
Filter the front of the complete optical system
A telescope, binoculars or camera requires a special-purpose solar filter securely fitted over the objective or aperture.
Eclipse glasses are intended for direct viewing according to their instructions. They are not filters for telescopes, binoculars or optical viewfinders.
Inspect the complete path first
Before every use inspect the filter for damage and verify its attachment. Secure it against accidental removal.
Remove or safely cover an unused finder and every parallel optical path. Nobody should be able to look through an unfiltered component.
Control the observing station
Set up away from casual passers-by and then follow the filter and telescope manufacturers’ procedures. Children require continuous supervision by someone familiar with the equipment.
Never leave a solar-pointed instrument unattended. If the filter is disturbed, stop and inspect the whole setup again.
Do not improvise
Do not use smoked glass, film, plates, material not intended for optical solar viewing, or small eyepiece-end filters.
If origin, condition or correct attachment cannot be confirmed, do not observe. A supervised public solar event is the safer alternative.
Common mistakes
- Holding eclipse glasses to the eye while looking through a telescope.
- Attaching a filter loosely or without protection from wind and contact.
- Leaving a finder uncovered.
- Testing unknown material with your own eyesight.
What to record in TelescopeTo
- Store filter type, manufacturer and compatible aperture in Equipment.
- Add checks for attachment, surface condition and finder coverage to the session plan.
- Record any change in condition after use; do not reuse a damaged filter.
Guide limits
This material is not a filter-building instruction or product certification. Follow only the special-purpose filter and instrument manufacturers’ instructions; when uncertain, do not observe.