As we have seen in this article, a convex secondary mirror can not be tested directly in general (*) . One of the methods is used to refer to a concave mirror which has the same shape of the surface that we want to get on the convex mirror. By overlaying the two mirrors, the analysis of the interference fringes by means of
ITALIAN TRANSLATION OF CHAPTER 8 THE BOOK "THE CONSTRUCTION OF THE AMATEUR TELESCOPE" Jean Texereau (NOTE: For French speaking readers, it is advised to read this article directly on the book he also took again, (pages 137 – 149) to avoid mistakes due to the double automatic translation). The main difficulty of the construction of a telescope in a combination
To "start off on the right foot" – given that the reader might not know the reason why in some types of telescope must create a secondary mirror of convex type, we make a "panoramic" on the evolution of telescopes that led to the use of this type of mirror. The refractor telescopes were the first to appear
