(p.2)
 
FILTERS
 
If you feel that you just have to look directly at the Sun, be absolutely sure that you have the correct filter. Just because a filter makes the Sun seem dim does not mean that it's blocking invisible infrared or ultraviolet radiation that will certainly cause eye damage in short order.
 
Do not use sunglasses, Polaroid filters, smoked glass, exposed color film, X-ray film, or photographic neutral density filters.
 
Make sure that the supplier of your solar filter is reputable and reliable. A few are listed below. You can, for instance, look at the Sun with a number 14 welder's glass. Get this from a welding supply store. Silver-based black-and-white photographic emulsions, when exposed and developed fully, can be used if you are experienced and knowledgeable in this area. You might need several layers. It's easier, though, to spend a couple of bucks on a filter you know is safe.

Unless you're quite knowledgeable and experienced, it's much safer not to use a telescope to watch the transit. However, if you choose to use a telescope, only use the filter supplied by the manufacturer or by a manufacturer who makes a filter specifically for the instrument you are using. In some cases though, even this is bad advice (see the solar filter below.)
 
  The suppliers of some cheap refractor telescopes supply a welder's glass filter (pictured left) that screws on to the eyepiece.

DO NOT USE THIS TYPE OF TELESCOPE FILTER!

They may heat up and crack as you are looking through the telescope. A proper solar filter always goes on the front end of the telescope, blocking the sunlight before it enters the optical system.

Thanks to the Orion Telescope Center for the loan of this unsafe filter. Orion does not sell these! They just had one around as a bad example. They are good and knowledgeable people.
 
By following the instructions above and using a modicum of good sense, you will be able to enjoy transits and solar eclipses.
 

Suppliers of Filters and Eclipse Glasses

Celestron International, 2835 Columbia St., Torrance, CA 90503. (310) 328-9560
<http://www.celestron.com>

Meade Instruments Corporation, 16542 Millikan Ave., Irvine, CA 92714. (714) 756-2291
<http://www.meade.com>

Orion Telescope Center, 3609 Buchanan St., San Francisco, CA 94123. (415) 931-9966
<http://www.telescope.com/home.jsp>

Rainbow Symphony, Inc., 6860 Canby Ave. #120, Reseda, CA 91335. (818) 708-8400
<http://www.rainbowsymphony.com/>
 
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