Posts Tagged ‘Sunspots’

Viewing a solar eclipse safely, Part II

31 May, 2009

Here are more ways you can try to observe a solar eclipse.

Photo: Nils ÖlmedalPROJECTION WITH BINOCULARS OR TELESCOPE

An adaptation of the Pinhole Projection Method of viewing a solar eclipse — projection using binoculars or a telescope.

Point a pair of binoculars (with one of the lenses covered) or a telescope towards the Sun and hold a white piece of paper behind the eyepiece. An image of the sun will come out the eyepiece and shine onto the paper, like an overhead projector would shine onto a screen.

Adjust the focus on the binoculars or telescope until the image of the sun has a sharp and not blurry edge. You can also adjust the distance of the paper from the eyepiece.

sunspotsFor best effect, the lens should be stable, e.g. place the binoculars a tripod. This technique can also be used to observe sunspots.

Warning: Do not look at the sun through the binoculars without proper protective filters.

Which leads us nicely to…

CAMERA AND TELESCOPE SOLAR FILTERS

Many telescope and camera companies provide metal-coated filters that are safe for viewing the Sun. They are more expensive than common Mylar, but expert observers generally like them better because they are available in various colours, such as a chromium filter through which the Sun looks orange. Through aluminized Mylar, the Sun is blue-gray. As with the Mylar, you can look directly at the Sun through these filters.

However, do not confuse these filters, which are designed to fit over the lens of a camera or the aperture of a telescope, with a so-called solar eyepiece for a telescope. Solar eyepieces are still sometimes sold with small amateur telescopes. They are not safe because of their tendency to absorb heat and crack, allowing the sunlight concentrated by the telescope’s full aperture to enter your eye.

Viewing the Sun’s disc on a video display screen (provided by a video camera or digital camera) is safe, although the camera itself may be damaged by direct exposure to the Sun. 

via: www.space.com and www.mreclipse.com