With this accessoire, you can safely observe the sun by projecting it onto the white field at the bottom of the pyramid. This allows you to see the sun in so-called white light and study sunspots in peace and with a relaxed view - even a transit of Mercury can be observed in this way.
The projection gives you a large image of the sun, which is high in contrast thanks to the side shielding from daylight.
Another advantage of the projection method is that several people can observe at the same time, for example school classes.
You can attach the pyramid just like a 1.25" eyepiece. Your telescope should have a diagonal mirror or Amici prism. The pyramid is ideal for use with refracting telescopes (lens telescopes).
You should only use inexpensive eyepieces. The heat can damage the connections between the optical elements in expensive eyepieces. You should also choose an eyepiece with a sufficiently long focal length so that the sun fits clearly into the field of view. This ensures that all of the sunlight passes through the eyepiece.
Our expert comment:
For safety reasons you should completely remove the finder scope from the telescope when observing the Sun. Under the search term "solar finder" you can find special finders with which you can safely set up the telescope to view the Sun.
It is recommended that you use simple Huygens eyepieces for projection.
You can calculate the size of the image of the Sun in millimeters using the following formula: Sun image diameter = 0.5 x distance between the image and the focal point x the magnification.
(Stefan Taube)
