How can we observe Venus?

On the day when the transit of Venus over the Sun will take place, the planet’s disk will have have the angle-average 58“. The resolving capacity of a healthy human eye is somewhere around 1‘. Thanks to this, it is possible to observe the transit even only by the eye. Nonetheless, it is essential to protect your vision by a filter, which is able to eliminate the vast majority of the solar light!!! Venus will be then projected into the bottom half of the solar disk as a small black dot and it will move from the left to the right. We will be able to see much more by binoculars and we will also have a bigger chance to conduct quite a precise measurement of the beginnings of each contacts (i.e. moments when the little disk of Venus touches the edges of the solar disk from either inside or outside; see attached picture). We will also be able to observe so-called effect of the Baily’s raindrop, an optical effect, that is distinguished by the “fusion“ of the black disk of Venus and the edge of the Sun. However, we should not forget, that some inverting telescopes (refractors) cause the inversion of the picture both horizontaly and verticaly. It is also important to use a filter of a sufficient quality, which has to be placed in front of the refractor’s lens. This filter allows only a low amount of light to penetrate, in order to keep the eyes in a secure environment! Never look at the Sun by a refractor (or binoculars) without using a filter!!! The safest way to observe the whole thing is to do that via a projection through the refractor. Using this method, we are not looking directly to the refractor (or binoculars), but we only observe the enlarged picture of the Sun with a small black dot on the shade behind the refractor (see the picture). If you are equipped with a camera, you can make a photo of the whole thing or video-tape it using a suitable reduction of the photographic body to the focal plane of the refractor. Again, it is essential to use a suitable filter, which is placed in front of the refractor’s lens.