17th Century Telescope

Here is an interesting modern replica of a 17th century long focus telescope. This was made by Robert May of California and has a lens with a diameter od 4.25-inches and a focal length of 200-inches (as wide as the Mt. Palomar mirror) which makes it an F/47 system. It has 3-inch eyepieces and by making adjustments, one can track objects for 20 minutes.