Solar Viewing Safety
If you’re familiar with upcoming events in the astronomy world, you’ve probably heard about the upcoming Great American Solar Eclipse on August 21st, 2017. It’s going to be one of the biggest solar-observing events in years, with excellent viewing across large parts of the continental United States.
While having high-quality solar equipment will help you get the most out of your eclipse viewing experience, it’s important to remember some basic safety precautions, which apply to all users.
Solar Viewing Safety Basics
The first rule of solar observing is to never look directly at the sun, as unprotected viewing of the sun can permanently damage your vision in a matter of seconds. Needless to say, we at OPT do not recommend staring directly at the sun for any amount of time, and doing so should always be avoided.
Solar Viewing Options
While looking directly at the sun without protection is dangerous, there are a variety of safe solar viewing options available.
These include solar glasses and binoculars, solar filters for telescopes and cameras, and dedicated solar telescopes.
Solar Glasses and Binoculars
Solar glasses and binos are the simplest options for solar observing and their ease-of-use make them great options for people without much previous astronomy experience.
Additionally, their low cost make them easy to acquire in large quantities for groups such as families and schools. They’re also a great option for children. While solar telescopes can be large and have a bit of a learning curve, glasses or binoculars are a better fit for small kids and are much easier for them to use.
While solar glasses and binoculars are great for all of these reasons, the safety rules still apply. Do not remove the glasses or binos while still staring at the sun. Also, be sure that any children who will use them understand and follow safe viewing practices.
Solar Filters for Telescopes and Cameras
If you want a better view of the sun than with solar glasses or binoculars, and you already have a telescope or camera, you might want to consider a solar filter. These attach to your telescope or camera for seamless solar viewing.
Just be sure that you get the correct size for the device you intend to use.
For cameras you’ll need to match the filter size to your camera’s lens diameter and for telescopes you’ll need to match the outer tube diameter size. For telescopes you should choose the next size up from your tube’s outer diameter, which will usually be 0.50” more than the measurement. Be sure that all filters are securely attached, following any included instructions.
Make sure to never point your telescope or camera towards the sun without the proper filter applied, as doing so may damage your equipment. Even if your equipment is not harmed, the light passing through an unfiltered telescope will be intensely focused on the other side of the eyepiece, much like a magnifying glass, creating a fire or burning hazard for whatever, or whomever, it is pointed towards. Needless to say, do not look at the sun through an unfiltered telescope, as the normal dangers to your vision will be multiplied.
Also, be mindful of any finderscopes or similar optical equipment attached to your telescope, as these will need to be covered or require their own filters if they are pointed towards the sun.
If you want a high-quality, dedicated piece of equipment for viewing the sun, we recommend a solar telescope. These come with a solar filter, so you won’t have a buy one separately. This means that choosing a separate filter is a non-issue. Just set up the solar scope, point it at the sun, and start observing.
Additional Safety Precautions
Whatever solar viewing option you choose, make sure you follow any included instructions. Do not to puncture, damage, tamper with, or otherwise misuse the solar equipment. Doing so could not only void any warranty that came with your equipment but could also compromise its ability to protect your eyesight. Since even the smallest break in a filter can allow damaging sunlight through, we cannot stress this highly enough.
When used correctly, solar equipment is highly safe. Quality control is of the utmost priority for solar equipment manufacturers and solar products are built to exacting safety specifications.
However, if you do encounter any issues or notice any wear that might compromise your equipment, discontinue using it immediately and follow any instructions related to the manufacturer’s product warranty, should it be valid. Your eyesight is too valuable to risk!
When using the proper equipment in the proper manner, solar observing is a great hobby that can be enjoyed by astronomers of all ages and skill levels. This is not only true of the upcoming Great American Solar Eclipse itself, but for solar observing all year round for years to come. As long the sun is out, and your equipment is set up, you’re good to go.
Happy solar observing!