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Pinhole images are pretty dim and small. There's another projection method that uses a pair of binoculars. DO NOT LOOK THROUGH THE BINOCULARS!
- First, you should firmly fix the binoculars to a tripod. You can do this with duct tape (what else?).
- Cut out a shield made of cardboard and tape it to the front of the binoculars with the lenses sticking through holes that you cut.
- Put the lens cap over one of the large binocular lenses or tape over one of the front lenses with duct tape. (You really only need a monocular for this.)
- Use the duct tape to seal any holes that leak light past the cardboard.
- Point the binocular towards the sun while holding a piece of white cardboard about a foot behind the eyepiece.
- It will take a little effort to find the sun. Once you do, you can focus the binoculars to bring the sun to a sharp image.
Be careful not to put your hand or anything flammable near the eyepiece! The concentrated sunlight exiting there can cause a nasty burn or set something ablaze!
Now you can watch a beautiful, bright, magnified image of the sun as the eclipse proceeds. You will have to adjust the tripod to account for the earth's rotation. One possible warning here. You might give your binoculars a cooling break now and then. The eyepiece may become overheated and the lens elements may separate if you leave it on the sun too long. You've been warned!
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 eclipse filter is reputable and reliable. A few are listed below. You can, for instance, look at the sun with a number 14 welders 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. If you want to use a filter on a telescope, only use the filter supplied by the manufacturer or by a manufacturer who makes the filter specifically for the instrument you are using. In some cases, this is bad advice.
The suppliers of some cheap refractors supply a welder's glass filter that screws on to the eyepiece. DO NOT USE THESE! 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.
Do not use this type of telescope filter:
(Click the image to see a larger view.)
By following the instructions above and using a modicum of good sense, you will be able to enjoy solar eclipse after solar eclipse. I have!
- Filter suppliers from Fred Espenak's wonderful web site
- Information about solar viewing from "Mr. Eclipse"
- ABELexpress - Astronomy Division, 230-Y E. Main St., Carnegie, PA 15106. (412) 279-0672
- Celestron International, 2835 Columbia St., Torrance, CA 90503. (310) 328-9560
- Meade Instruments Corporation, 16542 Millikan Ave., Irvine, CA 92714. (714) 756-2291
- Orion Telescope Center, 2450 17th Ave,, P.O. Box 1158-S, Santa Cruz, CA 95061 (408) 464-0446
- Thousand Oaks Optical, Box 4813, Thousand Oaks, California 91359 (805) 491-3642
- Rainbow Symphony, Inc., 6860 Canby Ave. #120, Reseda, CA 91335 (818) 708-8400
- Assistpoint Limited, 40 Allendale Road, Barnsley, South Yorkshire, S75 1BJ, United Kingdom (tel) 0114 238 7569