ถ้าคุณชอบ All about telescopes
Brown, Sam
A guide to information on selecting, building and using telescopes. It covers subject matter suited for beginners to advanced amateur astronomers. It covers a variety of topics including mirror grinding, polishing and testing; focal length determination; image-object problems; and homemade eyepieces. It also includes selections from other Edmund Scientific/Sam Brown publications such as "Telescopes You Can Build", "T…
