Binocular Prisms are what let you see a correctly

Roof prisms are essentially in line inside the optical tubes, and, therefore, a more compact set of binoculars. Roof prism binoculars have straight tubes with the bigger front lens or Objective lens in line with the smaller rear or Ocular lens and are therefore more compact. This is good thing for the sportsman. They usually have two pivot points between the tubes, and are more difficult to adjust to the spacing of your eyes. Roof prisms can give an optical image equal to the best Porro prisms, but for technical reasons they usually don't. To be really good, roof prism binoculars have to be in the high price class. Do not attempt to economize on roof prism binoculars. Porro prism binoculars are identified by their offset tubes; the front Objective lens is not in line with the back Ocular lens. The front lenses are usually closer together than the rear lenses, but the reverse can also be true, particularly in compact models. The Porro prism design is usually optically superior to the roof prism design, especially in medium priced class binoculars. Porro prism binoculars have a single pivot between the two halves of the binocular, and are therefore easy to adjust for the distance between your eyes. Either the Roof prism or the Porro prism binoculars will give you years of steady high quality viewing. It really is a matter of how you use them and how much you care about adjusting the lens. All binoculars work well for hunting, bird watching, sports events, and general star or scenery viewing. Your preference will usually come down to handling on a daily basis. Try out several types for different situations and then make up your mind about which is best for you and your viewing. Roger Johnson