Astronomy is traditionally a night owl’s hobby; the passion of a person who drives out to the country to escape the bright lights of the city. Not all exciting observations belong to the night though. The brightest object in the sky, our very own Sun, is an excellent telescopic target. There is only one way to view the Sun and that is safely. Our solar filters and solar telescope guide and reviews will show you how to choose a safe filter for viewing the Sun’s best features, and the top products for doing so safely.
Picking Filters like a Pro
You cannot compromise with eye protection when you plan on viewing the Sun. Looking at the Sun with unaided eyes is harmful enough, but looking at magnified sunlight using an inadequate filter is extremely dangerous with the potential to cause blindness.
Steer clear from filters that fit over eyepieces or eyepieces that serve as filters. This type of filter does not always block out enough of the Sun’s harmful rays. The intense heat of sunlight magnified through a telescope can crack these type of filters and expose your eyes to harmful rays.
Always choose a full aperture filter with the correct fit for your telescope. A filter of this kind is placed directly over the main objective of your telescope, blocking off the majority of sunlight before it even enters your telescope.
H-alpha filters with a waveband of 656 nanometres are an excellent choice as they show provide the best contrast for the majority of solar features, but white light filters are just as safe and allow you to see a variety of features albeit with less contrast and dimension.
The Sun is so different from any of the celestial bodies we view at night. It is both beautiful and challenging to observe. Here are a few (not all) solar features you can expect to see through a telescope.
Prominences: Prominences are arches of hot gas that rise up from the chromosphere, extending up to 50 000 kilometres or more above the Sun’s surface. They can last for up to three months before reaching these heights, and then erupt great amounts of solar material in a few minutes or a couple of hours. These coronal mass ejections race off into space at speeds of 1000 kilometres per second. Prominences can get carried along the disk the Sun as it rotates, sometimes stretching half way across the Sun. Prominences are called filaments when they appear as dark, snakelike arches contrasted against the bright photosphere.
Spicules: Spicules are visible as dark red tubes on the Sun’s surface, running all along the edge of the Sun’s disk. Approximately 300 000 spicules cover the chromosphere at a time. They are huge jets of hot gas that can reach 10 000 kilometres in height. They are also short lived, usually lasting no more than 15 minutes.
Sunspots: Sunspots are caused by incredibly strong magnetic fields that break through the Sun’s surface and appear as dark, cool areas on the Sun’s bright photosphere. There are several interesting elements to sunspots. Firstly, they always come in pairs. Sunspots also follow an 11 year cycle where they become more and more numerous before reaching a maximum, and then become less numerous until the cycle is repeated.
Solar Flares: Solar flares are abrupt explosions erupting from the Sun and are believed to be caused by sudden changes in the Sun’s magnetic field. They are often associated with complex groups of sunspots. Solar flares can be quite powerful and also disruptive. The particles released from a solar flare interact with the Earth’s magnetic field and cause aurora, and can also disturb satellites and communication and navigation systems.
Best Solar Telescopes
Look no further than these excellent solar filters and telescopes for exiting views of the Sun and peace of mind knowing that your vision is protected.
Meade Day and Night Telescope
Meade offer this incredibly versatile telescope at a very reasonable price. The main feature is a removable white light filter that easily allows you to switch between detailed solar observations and crystal clear images of the night sky. It is a perfectly compact device, light weight and portable. The Day and Night Telescope comes with 26mm and 9mm eyepieces so that you have a choice of low or high magnifications. Its 360° swivel mount makes this telescope a dream to use. This solid telescope has the perfect credentials including being certified safe for solar viewing.
Meade Instruments Coronado Personal Solar Telescope
Coronado Personal Telescope is an affordable item from a trusted name. The telescope offers a 40mm H-alpha optical system which shows quality views of sunspots, flares and more all in a natural deep red colour. It does not come with its own mount, and will require and sturdy tripod. A great feature is the option to adjust the frequency of the solar filter..
Lunt Solar Systems 100 mm H-alpha High Desert Solar Telescope Package
The Lunt Package certainly does not come cheap, but for skilled and dedicated solar-observers it is without a doubt worth every penny spent. Lunt’s instrument offers fine pressure tuning and an 18mm block filter. The 100mm telescope provides some of the sharpest and most detailed views of solar features of any amateur device. Observe solar flares, filaments, sunspots and spicules with the greatest ease. The telescope is also perfectly designed for safe imaging with your camera.
Best Solar Filters
Gosky Eclipse Solar Filter
Put safety first with this full aperture white light filters from Gosky. The front-end attachable filter is designed for telescopes with an aperture of 66mm – 95mm. This is a wonderful filter for safely viewing solar eclipses sunspots and planetary transits of Mercury and Venus. It is made from quality German Baader film that guarantees no distortions and only the clearest views. A good mid-price filter.
Thousand Oaks Optical Solar Filter Sheet for Telescopes, Binoculars and Cameras
If you are willing to try your hand at DYI solar filters that you can be sure are quality tools and safe to use, these solar filter sheets from thousand Oaks Optical make a fine choice. They are made from black polymer, a popular and good material for solar filters. This is a cost effective and versatile option to higher-end filters which may be out of your budget. The filter provides natural views of the Sun. It is important that the sheets are cut accurately to fit the optical device of your choice, and attached securely so it does not fall off during use and expose your eyes to harmful UV radiation.
Thousand Oaks Optical SolarLite Solar Filter for Telescopes
The SolarLite is the perfect filter for popular telescopes on the market. The filter has the optical quality of glass and is made with optical black polymer. Thousand Oaks Optical pride themselves on the superior durability of this filter which will not break, develop pinholes or scratches. And to put the money where Thousand Oaks’ mouth is, they offer a 15 year guarantee on this superb filter.
Orion 07710 5.81 Inch ID Full Aperture Glass Telescope Solar Filter
Orion brings you an optical glass full aperture filter that blocks 99.9 of the sun’s harmful light so that you can safely view a full variety of the Sun’s features. The filter is made to fit a range of telescopes with apertures of 5.56 inches to 5.1inches. Orion’s filter allows you to view the Sun in its natural yellow/ orange colour ideal for solar photography.
Viewing the Sun with these excellent solar telescopes and filters will change everything you thought you knew about our star. It goes from being a featureless and painfully bright object you cannot look at, to a powerful and dynamic star you will never want to stop viewing.