The sun is a fascinating, dynamic object. Its surface is surprisingly detailed and changes frequently. The observing hours are more convenient. However, there are a few rules to follow before using your telescope on the sun. The first rule of solar observing is never point your telescope at the sun without a proper filter. The second rule of solar observing is always inspect the filter before placing it on your telescope prior to observing to ensure that there are no defects (scratches or pinholes) that could damage your eyes or equipment. If you discover any defects, DO NOT USE THE FILTER—IRREVOCABLE EYE DAMAGE COULD RESULT FROM THE USE OF A DAMAGED SOLAR FILTER.

Astrozap offers two kinds of full aperture and off-axis solar filters using Baader film and glass materials to fit all popular telescope sizes. Each Astrozap Solar Filter is equipped with one or more plastic retaining screws, depending on the filter's size, that do not mar or scratch the telescope's finish. Astrozap Solar Filters are available in several configurations including full aperture, off-axis and matched pairs for binoculars. Astrozap Solar Filters are proudly made in the USA. When available, Astrozap carries precut sizes of Baader film for the do-it-yourselfer who wants to build a custom sized filter.

Baader film produces a bluish-white image while glass produces an orangey image. Some solar observers believe Baader film provides better contrast. Others prefer the warmer color produced by a glass filter. Buy an Astrozap solar filter and turn your present telescope into a solar observatory. Which filter to choose depends upon personal preference. If you can't decide, buy one of each and compare and contrast the images each filter produces. We'd like to know!

A note on choosing a solar filter:

Each solar filter size listing represents the outside diameter of the telescope's OTA or dew shield that the filter is designed to cover. We suggest that you measure the diameter of the objective end or dew shield of your OTA in millimeters and select a filter in a size large enough to cover the objective completely. For binoculars, measure the outside of both objective lenses Do not wait until the week of the event to confirm that your solar filter fits your telescope or binoculars, and can be secured in its place in front of your telescope's objective or binocular lenses. Once you receive your order, immediately check and verify that the filter is undamaged, that it fits over the objective(s) completely, and that the adjustment screws tighten enough to hold the filter in place. You must confirm this before attempting to point your telescope or binoculars at the sun in order to ensure that the filter protects your eyes and your equipment. If the filter does not completely cover the objective(s), or is loose and does not stay firmly in place, or if it shows signs of damage, do not use the filter or point your optical equipment at the sun. Ever. Failure to verify the integrity, full coverage and secure fastening of your filter before each use will result in damaged optics and permanent injury to your eyes.

Baader Solar Filters

by Astrozap

With AstroSolar™ the Sun appears in neutral white. Other films and some glass filters produce a blurry bluish or reddish Solar image, thereby cutting part of the spectrum. Especially with an orange sun, it is very hard to see faculae regions which are visible predominantly in the blue wing of the spectrum.

Due to it's neutral color balance, AstroSolar enables the use of various color (or interference) filters which allows the observer to concentrate on certain spectral passbands for investigations of different layers within the solar "atmosphere".

AstroSolar™ is essentially free from pinholes, since - other than with even the most expensive glass filters - it is coated on both sides, so that the chance of two pinholes overlapping each other is extremely faint. Pinholes do appear, but to 1 out of 10000 only in optical density 2.5! Baader AstroSolar™ safety film has been approved for eye safety by the National Bureau of Standards in Germany, the PTB. Unlike any other Solar Filter on the market, AstroSolar™ is CE-tested according to EG-Norm 89/686 and EN 169/92 ( notified body 0196). All processes connected to this product have been thoroughly tested. Coatings are inspected constantly for consistency to ensure your eye safety!

Baader AstroSolar™ film Filter cell constructed from lightweight 18Ga. aluminum and powder coated white. Heavy duty threaded inserts and nylon thumbscrews insure a secure fit

Full Aperture - Glass Solar Filters

by Astrozap

Full Aperture Glass Solar Filters fit telescopes/finders/cameras/spotting scopes/binoculars as shown in the Size Matching Specifications below.

These are safe full aperture (sometimes referred as clear aperture) solar filters. This means that it allows the most light possible into the telescope because it allows the full aperture of your telescope to be viewed. The full aperture allows the best possible daytime viewing when there is minimal atmospheric turbulence. If turbulence is present a mask can be put over the end of the filter to effectively reduce the aperture.

This premium solar filter has an aluminum cell that is secured and centered to the tube end of the telescope with nylon thumb screws and felt padding. The clear aperture is made with high quality hand selected and inspected reflective coated glass. This is the highest quality, durable, glass, full aperture solar filter on the market. The sun is viewed in a natural yellowish-orange image. The filter can be used for direct viewing through the telescope or for photography.

The filter box is foam lined for protection and shock absorption during handling. It is durable enough to store the filter while not in use.

Off Axis - Glass Solar Filters

by Astrozap

Off Axis Glass Solar Filters that fit telescopes as shown in the Size Matching Specifications below.

These are safe off axis solar telescope filters. An off axis solar filter blocks light into the telescope by only allowing light through a small portion of glass that is off center. By reducing the aperture the image is not darker but visibility of daytime atmospheric turbulence is reduced. The off axis is less expensive than the full aperture solar filters.

This premium solar filter has an aluminum cell that is secured and centered to the tube end of the telescope with nylon thumb screws and felt padding. The aperture portion of the filter is to be positioned as close to 12 o’clock as possible. The off axis aperture is made with high quality hand selected and inspected reflective coated glass. This is the highest quality, most durable, off axis aperture, glass solar filter on the market. The sun is viewed in a natural yellowish-orange image. The filter can be used for direct viewing through the telescope or for photography. You should be able to see sunspots, granulation, and of course a solar eclipse.

This filter is new in the box in plastic. The filter box is foam lined for protection and shock absorption during handling. It is durable enough to store the filter while not in use. With the filter come instructions for use and care.

Email for quote vernonte@telus.net