Why a 2-inch Eyepiece?
Finally, this is probably a good place to bring up the subject of eyepiece barrel size. A long focal length eyepiece (around 32mm and up) will give you a very wide actual field of view, but to gain the most value from such a long focal length, the eyepiece should be in the 2-inch format, rather than 1-inch. If not, the barrel of the eyepiece itself will cut off some of the field that youd otherwise be able to see. Were referring here to the true field, not just the apparent FOV that is always advertised. Of course, youd need a 2-inch focuser, but the potential increase in the angular field of view is roughly 2″+ 1″ = 1.6, or a 60% increase. … published in the July 2001 issue of the NightTimes Webmaster: webmaster@lcas-astronomy.
