Porro Prism vs Roof Prism Binoculars – Which is the Best?

April 30, 2019 6 Comments

roof or porro

There are two types of binoculars available in optics world, Porro prism and roof prism binoculars. Both optics are good though there is some difference.

Porro prism binoculars have eyepieces that are closer to each other while objective lenses have larger distance.

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.




Most binoculars available today are roof prism binoculars and they are more pricey.

But optics manufacturers nowadays try to manufacture both expensive and budget roof binoculars to make them available to end users.

Because most people prefer light binoculars over heavy ones which is easily achievable with roof prism binoculars.

Generally speaking and without going much into details both binoculars are great and deliver what they must deliver – they both produce high quality image which is the ultimate goal of any optical device, binocular, monocular or telescope.

But there is some slight difference though. Porro prism binoculars produce a little better image in terms of increased 3D effect.

But not all Porro prism binoculars produce such an image. I have various sets of binoculars, such as military binocular Baigish, Pentax, Bresser.

Bresser does produce the best image quality in terms of increased 3D effect.

Roof prism binoculars are more compact, lightweight but they are more expensive.

Because their optical system is more complicated which means production costs are higher.

Almost any Porro prism binocular can be mounted on a tripod while not every roof binocular can.

Because roof binocular barrels are close to each other and if the distance between your eyes is short then barrels can’t be adjusted to your eyes if you want to use your binocular on a tripod.

You need to buy a tripod adaptor designed specifically for roof binoculars.


tripod adaptor


In short, if you are on a tight budget you better choose a Porro prism binocular if you want a high quality image.

But this doesn’t mean image in roof prism binoculars is bad. Not at all. I will try to explain.

For example a Porro prism binocular produces image quality equal to 5 score out of five and the price is $100.

If you want to get the same image quality and want to choose a roof prism binocular then such a binocular will cost you at least $150. This is just a rough example.


Secret tip: Do you know why prisms are used in the binoculars? Because without prisms your viewing object would look upside down.


If you look at the screenshot below you will notice that in porro binoculars prisms are arranged in a zig zag form which is why porro binoculars have bigger sizes compared to roof binoculars.


Question: Is image in porro very different from roof  binoculars?

Answer: I can’t say the difference is huge. There is some difference though. In good porro binoculars image has a stereoscopic, 3D effect and looks more interesting. This applies to pricey, well-made porro binoculars only. In roof well made binoculars the same effect can be achieved but the price will be higher.



Advantages of porro prism binoculars

  • Image is more stereoscopic
  • Cheap models available
  • Can be used on a tripod


Disadvantages of porro prism binoculars

  • Heavier than roof binoculars
  • Too many fake zoom binoculars


Roof prism binoculars are well known as more compact and lightweight which makes them more popular than porro binoculars.


open bridge vs closed bridge


There are mainly two types of roof binoculars: open bridge and closed bridge binoculars. Open bridge optical devices can be easily used on a tripod.

Closed bridge binoculars are less friendly in that sense due to binocular barrels being too close to each other. You need a special tripod adaptor.

In roof binoculars prisms are arranged in a straight line which makes roof binoculars more compact and lightweight compared to porro binoculars.


roof-porro prism


Prism in roof binoculars doesn’t reflect 100% of the light that enters its lenses. That’s why usually porro binoculars produce brighter image.

Expensive roof binoculars correct the situation by improving lens coatings.

In most expensive roof binoculars manufacturers use dielectric prism coatings which allows to reflect 99% of the light that passes through the binocular.

In less expensive roof binoculars manufacturers apply silver mirror coatings that allows to reflect 98% of the light.

Other materials used in roof binoculars allow to reflect only 93% of the light. This can be found in cheap roof binoculars.

When it comes to Porro binoculars, manufacturers don’t apply such coatings and still binocular can reflect 99% of the light.

That’s why image quality that you get in porro binocular for $100 can be achieved in roof binocular for $150 or for a much higher price.



Advantages of roof prism binoculars

  • More compact and lightweight
  • More user friendly
  • Can sometimes outperform porro binocular


Disadvantages of roof prism binoculars

  • Specific tripod adapter required to use binocular on a tripod
  • More pricey than porro binoculars


choose binocular


Which binocular to choose?

Just for your information, to ensure a good image quality produced by binoculars manufacturers apply coatings to binocular lenses.

The best type of coating is a fully multi-coated lens coating vs fully coated or multi coated lenses. It also depends on how manufacturer does it.

Multi coated lenses from manufacturers such as Nikon, Vortex, Zeiss can easily outperform fully multi coated lenses from a china manufacturer.

This means it’s always better to choose binoculars from well known manufacturers. See the list below.


  • Athlon
  • Bushnell
  • Barska
  • Bresser
  • Baigish
  • Carson
  • Canon
  • Celestron
  • Gosky
  • Leica
  • Leupold
  • Levenhuk
  • Maven
  • Meopta
  • Nikon
  • Orion
  • Oberwerk
  • Pentax
  • Swarovski
  • Steiner
  • Wingspan
  • Vortex
  • Vanguard
  • Zeiss



As I said above, if you are on a tight budget and want to have the best binocular with the best coatings and image quality then choose porro prism binoculars.

By this I don’t mean you can’t get a good pair of roof binocular at a reasonable price. Definitely you can get such a binocular under $100.

There is also an outdated opinion going around on the internet that porro binoculars are not waterproof.

This is true if you buy binoculars from a china from unknown manufacturer.

If you choose from manufacturers listed above then usually all their binoculars are waterproof and fogproof.


eyepiece distance


Porro and Roof binoculars: Eyepiece distance

There is also an opinion that the distance between eyepieces in roof binoculars is too small. There is an optical illusion here.

In fact, the distance between eyepieces is almost the same and you can see it on the screenshot below.


roof porro comparison


Though not all porro binoculars are the same.


porro porro comparison


Some of them have larger distance between eyepieces. For example, my son who is 8 can’t use my Levenhuk roof binocular because the distance between eyepieces is too large for him.

He does use my military porro binocular Baigish that fits his eyes perfectly.

In short, if you buy roof binocular for yourself it will fit your eyes perfectly.

If you buy it for your child then you better choose roof binoculars designed for children or choose porro binoculars.

Also, when you use roof or porro binoculars usually they have eyecups that you need to twist up to the full to avoid seeing black spots when looking through binoculars.

Adjust them as well as binocular barrels to avoid those black spots. An example of black spots can be seen on the screenshot.


black spots


I think since roof binoculars outnumber porro binoculars it means roof binoculars have more models, modern and beautiful and it’s much easier to choose from roof binoculars.



Final tips to help you get the best set of binocular for your money


  • Porro prism binocular is heavier than roof prism binocular
  • Porro binoculars produce more stereoscopic image
  • Porro binoculars are cheaper than roof binoculars
  • All porro binoculars can be used on a tripod
  • Porro binoculars are usually waterproof and fogproof if you choose a pair from well known manufacturers listed above
  • Roof binoculars are more compact and lightweight
  • Special tripod adaptor required for using roof binocular on a tripod
  • Roof binoculars are more pricey than porro binoculars
  • Only expensive roof binoculars can outperform porro binoculars
  • If you plan to use binocular on a tripod make sure to check if roof binocular you plan to buy does meet your requirements.
  • Roof binoculars are good for hunters, fishermen and travellers.
  • Roof binocular that has dielectric or silver coatings can easily perform as well as porro does or even outperform porro binoculars. Sometimes it can be  even cheaper than porro binocular.



About the Author:

We review and recommend quality binoculars so you don't waste your money on useless ones.

Comments (6)

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  1. Victory says:

    I never really understood the mechanics behind a pair of binoculars, let alone the difference between a Porro Prism and Roof Prism binocular, until I came across this website. I’ve always wandered on how to tell the difference between a good pair of binoculars and a pair of rip-offs, so I enjoyed reading some of your posts. It’s a wonderful to be educated about what you’re buying.

    Also, the assistance bubble chat is a very nice touch. Keep up the great work 🙂


    • Adam says:

      That’s true Victory. There are many fake binoculars and it’s always recommended to do some research before making a purchase. It’s good to know you did so and found my site and I’m glad it helped you.

  2. Graham says:

    Now I know the difference between the two types of binocular, I have often wondered how the narrower types were made. I also didnt know the different names. After reading a well written and researched article, I will be more prepared to make a correct choice of binocular when ready.

    Thankyou for a very informative and well written topic.

    • Adam says:

      Great Graham! If you need any advice drop me a message and I will gladly help you choose the right binocular.

  3. rjkennedy says:

    When it comes down to quality binoculars, just like anything else, it’s always in the name; the company that produces the item. Choosing the right set of binoculars is an important step for users. I never was too much into binoculars, probably because I never served in the US military, but I see on the site there are some specially designed for army personnel.

    I guess folks who want to stay within a budget, your site give readers alternatives to saving money and also recommended binoculars for those who want to stay within a certain budget! (Remember, you get what you pay for.)

    I plan to buy a binocular for my general use purposes. What can you recommend within my budget $150 ?

    • Adam says:

      I can recommend you magnification 8x for general use. After clicking the link you will see the very first binocular Wingspan ( Wingspan Optics NaturePro HD 8X42 Professional Binoculars) that is around $124. It’s a good one and not so pricey. Or you can choose another Wingspan ( Wingspan Optics Spectator 8X32 Compact Binoculars) for $64. Just scroll down the page and you will see it. If you have more budget I highly recommend Nikon ( Nikon Monarch 8×42) for $239.

      If you have other questions let me know and I will help.

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