If this is your first solar eclipse, and you plan to bring a telescope or camera, make sure you have a safe and secure solar filter! This article summarizes some important safety information on using solar filters, including types of filters you need to avoid. We don't sell solar filters (other than the Eclipse Glasses) so I'm also including a list and links to known quality solar filter providers.
Solar Filter Safety
If you would like to observe the eclipse with a telescope, binoculars, or a camera, don’t get sucked into money saving “tricks” to block the light – spend a little bit of money on certified solar filters, and be safe. Most solar filters for telescopes or binoculars are designed to be placed over the objective – the end pointed at what you are viewing - not at the eyepiece.
In years past, some cheap telescopes came with a solar filter that could be threaded onto the eyepiece. Never use these eyepiece solar filters. Heat buildup can cause them to crack, leading to potential eye damage. Throw them in the trash! If you happen to be looking through the eyepiece when a filter like that fails, severe eye damage could occur. The only type of safe solar filter that can be used on the eyepiece end of a telescope (and then only on refractor telescopes) is known as a Herschel wedge, which start at around $250. Don’t worry though – high quality and safe white light solar filters can be had for less than $50.
Be aware there are some companies looking to make a buck while selling you filters that are not certified, and may not be safe! Look for filters that use ISO certified solar film or glass coatings.
Solar Filter Suppliers
Rainbow Symphony - A provider of quality ISO certified eclipse glasses and solar filters. They have solar filters from $20 in various sizes. (As of July 5, they are experience a backlog of 1.5-2 weeks shipping new orders.)
Orion Telescopes and Binoculars - Telescope company that offers solar filters in a range of sizes. Mostly glass filters, which are more expensive than mylar filters, but are designed to be used for years if properly cared for. (I've had one of their filters for my 80mm telescope for 3 years now, and it is still in perfect condition.) NOTE: this is an affiliate link.
Thousand Oaks Optical - Manufacturer of solar filters for many years. Quality and certified solar filters. Note they are backlogged by 3 weeks as of this writing (7/5)