Eclipse Safety Page

Eclipse Safety

Solar Filters - Time for an International Standard

Courtesy of B. Ralph Chou, MSc, OD;

Associate Professor; School of Optometry, University of Waterloo;Waterloo, Ontario, Canada

N2L 3G1 and Registrar College of Optometrists of Ontario

Check the R-G solar film for any possible damage before each use. If the film has been damaged please destroy the film immediately. Avoid any physical contact with the R-G solar film itself as this may cause scratches or even worse, cuts that destroy the film. “Wrinkles” in the film are normal and will not degrade the performance. Please see below in the “Cleaning & Inspection” section.
The filtering must be done at the front of the lens or telescope tube. Do not use the substrate at the eyepiece or viewfinder.
Always secure the solar filter to the telescope, binoculars or camera. We recommend using 2-4 Velcro strips to secure the filter in place. Point instrument away from the sun before removing the solar filter.
Do not leave the telescope, binoculars or camera unattended where children or inexperienced adults can point the instruments at the sun without the filter properly attached.
Keep the finder-scope covered if not equipped with a solar filter.
"Ghosting" can occur due to internal reflections. If this is a problem, simply tilt the filter slightly. (Glass only)
Point the telescope, binoculars, or camera away from the sun before installing or removing the solar filter.
Do not place your filter up against a smaller telescope. The end of the tube will damage the coating and film.
Allow the instrument and filter to equalize to the outside temperature for at least 15 minutes.
Direct sunlight may warm the tube assembly of your instrument enough to cause internal heat currents that can degrade image quality. Cover the tube assembly with a light colored cloth. Please note all the intense light from the sun is blocked before it can enter the instrument by the solar filter.
If possible, do not view over pavement or buildings. Viewing over grass will help avoid surface heat currents.