The prims are in the shape of a right angled triangle and they reflect the light rays through the binoculars so you see your image clearly.
Roof and porro binoculars.
If you see a pair of straight tube binoculars there s a good chance you re looking at a set equipped with roof prisms.
Its better to choose a binocular equipped with any of the prism types.
Porro prisms part 3.
Porro and roof binoculars.
There is an optical illusion here.
They re more compact and streamlined lighter weight and much easier to carry around than the bulky porro style binos.
Porro prism binoculars were standard until the 1960 s when the zeiss.
Binocular power and light part 5.
Binocular coatings part 4.
Choosing a binocular part 9.
Binoculars are chiefly available in roof prism and porro prism categories and a prism is used to correct the image orientation created by the lens.
In fact the distance between eyepieces is almost the same and you can see it on the screenshot below.
Roof prisms are the newer option.
Field of view part 6.
Eye relief and birding eyeglasses part 7.
Porro prism binoculars however do not need these coatings to reflect the same amount of light and so can match the better quality roof prisms at a lower cost.
How binoculars work part 2.
The future of birding optics roof prisms vs porro prisms.
Porro prisms are the more traditional ones and these are seen in older binoculars with a zig zag shape.
Comparing binoculars part 8.
These are the more modern of the two types of binoculars.