What is a triplet refractor telescope?
A triplet refracting telescope — also known as a “triplet” — is a telescope that uses three lenses instead of the standard two lenses of a doublet telescope. While triplets are much more expensive than doublets, that additional cost delivers a significantly cleaner view and better color correction.
What is the difference between a doublet and a triplet telescope?
A doublet (short for a doublet refracting telescope) uses two lenses, whereas a triplet uses three lenses. In a doublet, the lens configuration helps reduce chromatic aberration. A triplet improves upon this with better color correction and an even cleaner view.