Porro prism binoculars have eyepieces that are closer to each other while objective lenses have larger distance.
Roof or porro prism for astronomy.
Porro prism is made to increase the light in its path and increase the magnification so that we can get a clear bright image.
The objective lens tube of porro prism is offset from the eyepiece.
Most binoculars marketed for astronomy use porro prisms named for the italian optician who invented them in the 1850s.
Roof prism binoculars construction is different and have two aligned barrels with eyepieces and objective lenses that are closer to each other than in porro prism binoculars.
Of both types there are good and not so good instruments.
Briefly a roof prism needs to be made to a much higher optical standard than does a porro prism you will therefore in general get the equivalent optical quality for less money if you opt for a porro prism binocular.
Porro prism includes two right angled prisms that are facing each other.
Non total internal reflection one of the main drawbacks of the roof prism is a surface of the prism does not reflect 100 of the light that hits it meaning that left untreated less light exits and you get a lower quality less bright image with the possibility of some vignetting.
Roof binoculars have a narrow hinge tween the oculars and they look like a large letter h.
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 prism units are smaller and lighter weight but have a more complicated touchy optical design which makes them more difficult and expensive to manufacture well.
If you are traveling with your binoculars roof binoculars will be a better choice than porro prism binoculars because they are designed to be a lot more durable and are usually waterproof.
As roof prism binoculars are very expensive keep them out of kids reach.
That is why we called it porro prism.
However compared to the porro prism the roof prism does have a couple of drawbacks.
Roof prism binoculars have lately become more popular than porro prism binoculars.
However porro prism binoculars are great watching birds or other small objects.
If the price is your point of consideration and you are looking for a less expensive binocular then better to go for porro prism binoculars.
Porro prism vs roof prism binoculars which is better.
The question of porro prism or roof prism inevitably arises see here for more information.
It is difficult to say whether porro prism or roof prism binoculars are better.
These binoculars are for the more serious user who wants to get out and get dirty.
However if you want to go for the best quality viewing experience then go for roof prism binoculars.
