The two types of binoculars available in market today come in 2 general designs: Porro Prism Binoculars and Roof Prism Binoculars. They both use image-erecting prisms so you can see images in the correct orientation.
See the comparison of the two here:
| Prism |
Roof |
Porro |
| General Information |
Have straight tubes
Newer design by Zeiss and Leitz companies during the 1960s
|
Named after Italian designer Ignazio Porro
Standard design pre-1960s |
| Design |
The straight tube design gives the appearance of light traveling in a straight path with complex light path
High-end roof prism binoculars requires more complex light pathways and are usually costly as a result
|
A classic “dog leg”, wider frame design
The objective lens is spaced offset from the eyepiece
Simpler light path with higher light efficiency |
| Advantages |
Generally more compact
Easier to carry around on traveling trips or to spectator events
|
Rich depth of field & wide field of view
Lower cost to produce |
| Disadvantages |
In most cases, roof prisms are much more expensive to produce
Requires more optical precision to manufacture
Comparing dollar-for-dollar, the roof prisms are more costly for the same performance as the Porro
|
Bulkier design
The less expensive prisms (the BK-7) may not have circular, perfect exit pupils |
Figure 2.1 Comparison between Roof and Porro Binoculars
Other Special Features of Binoculars
