A Porro Prism or Roof Prism Designed Safari Binocular: Which is the best?
The first thing that strikes you about a Safari Binocular, is the apparent difference in two basic types of designs. All binoculars either use “porro prisms” or “roof prisms”. The ones using porro prisms are the traditional design where the eye pieces are off-center to the barrels. In normal size binoculars the objective lenses are further apart than the eyepieces. These binoculars are more bulky and heavier than the roof prism binoculars. An example of a porro safari binocular, is the Steiner 7×50 marine binocular.In compact binoculars, however, the manufacturers addressed the problem of the bulkiness in an ingenious way. In this design the eyepieces are wider apart than the objective lenses, which are placed as close together as possible – design known as “reverse porro”. A good example of a reverse porro design is the Pentax Papilio.In the case of the ones using roof prisms, the eyepieces are in line with the objective lenses and the overall design is sleek. A good example of this type of binocular is the well-known Nikon Monarch. These binoculars not as heavy as the the porro’s. The advantages of porro prism Binoculars are cost (less expensive) and the greater three-dimensional viewing effect, whereas roof prism binoculars are more compact and lighter (could even fit into one’s shirt pocket!), but are usually more expensive due to the more complicated manufacturing process. Apparently it is also easier to weatherproof a roof prism safari binocular than a porro.So: Which design is the best as safari binocular? Clearly both designs have pros and cons, but if you travel a lot and need something really light-weight and compact, you will have to go for a roof prism design, but should at least compare them to some reverse porro’s before making you final decision.If weight and size is no issue, either a porro or a roof prism safari binocular will do.
