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To the extent possible under law, Steven Ford has waived all copyright and related or neighboring rights to this work. This work is published from: United States.  The project home is https://github.com/fordsfords/astronomy

Homemade Non-Magnifying Finder

These are plans on how to build a very primitive non-magnifying finder scope. Hopefully you won't need this at all, but many people can't get the hang of using the "both eyes open" method with a normal finder scope. If you have money to spend on a high-tech solution, get a "Telrad" for about $50 US. If you're on a shoe-string budget, read on.

Here's what you need:

• Cardboard tube from a roll of paper towels.
• Sheet of heavy paper - black construction paper works well.
• Glue.
• Some rubber bands.

Here's how to build it:

1. Cut out a disk from the paper. It should be just a little bit bigger around than the paper towel tube.
2. Cut a smaller circular hole out of the middle of the disk. It can help to fold the disk in half while cutting. The hole should be about one centimeter in diameter (a little over a quarter inch, a little smaller than a US dime).
3. Glue the disk to the end of the tube. It helps to apply a thin bead of glue around the outer edge of the disk and then lower the tube onto it.
4. Let it dry.
5. Attach the tube to the telescope with rubber bands, keeping the tube as perfectly straight along the line of the telescope as possible. The open end of the tube should point toward the sky, the "glued disk" end toward your eye.

Here's how to adjust it:

1. During the day time, point the telescope at some easily seen landmark. Center that landmark in the telescope's eyepiece. The top of a distant evergreen tree works well.
2. Put one eye up to the cardboard tube. Keep both eyes open! Adjust the tube so that the landmark appears in the center of the circle formed by the open end of the tube. This may require inserting small spacers (bits of cardboard taped together) between the cardboard tube and the tube of the telescope.

The biggest problem with this finder is that the slightest nudge will knock it out of adjustment. I suppose I could glue it, but I don't want the thing to be a permanent fixture on my scope. Perhaps some kind of rubber cement that will stick fairly well but can be rubbed off after use? Let me know if you come up with a good solution.

Fortunately, the finder doesn't have to be precisely adjusted. Just so long as it gets the target into the view of the regular finder scope, you should be all right. Of course, you still have to deal with the upside-down view of the regular finder, but that's something you'll just have to get used to.

By the way, would it be helpful to include a picture or graphic? Or is it pretty easy to understand what I'm doing?

Sfordsez: if you haven't seen my standard disclaimer and copyright at http://www.geeky-boy.com/standard.html then check it out now.