iOptron's 70x900 Refractor is a great value option for a new astronomer looking to take a first peek into the majesty of the night sky. The 70x900 from iOptron is well suited to lunar and planetary observation, and can also be used for terrestrial viewing such as bird watching. 70x900 stands for 70mm aperture, 900mm focal length. This results in a f/12.8 focal ratio which is great for observation, but not suitable for imaging. The long focal length and relatively solid aperture combine to permit detailed observation of the moon and planetary targets in our solar system.