Porro Prism vs Roof Prism Binoculars: A Complete Overview

Do you ever think about how we can see magnified images via binoculars?

Only magnification power and objective lens work behind this or something else?

You may also know about prisms if you are a binocular fan. Two types of prism such as Porro and roof are used to design binoculars.

And, prism is also responsible for displaying the correct orientation, detailing, and bright images.

However, it seems the same from the user side, but the working principle, functionality, glass replacement, and performances are quite different from the Porro and roof prism binoculars.

So, in this article, I will discuss A to Z on Porro prism vs roof prism binoculars.

What Does Prism Do in Binoculars?

Before starting the comparison, I would love to give a short brief on the prism and its role in binoculars.

As a result, you can easily relate further terms in this roof prism vs Porro prism binoculars comparison.

Well, a prism is a glass piece that has plane faces as well as precise angles.

The main goal of using a prism in a binocular is to make the orientation of the magnified images correct.

As the objective lens delivers upside-down and downside-up images, the prisms are placed to rotate the image in the right direction. As a result, the user can see the actual view.

Besides, prisms are useful to reflect the light path effectively.

That makes the binocular pairs lighter and smaller.

However, both Porro and roof prism are assigned to do the same task but in 2 different ways.

We will get to know the working method in the comparison section.

Hold for a second and have a look at what the Porro prism and roof prism binoculars are in short.

What is Porro Prism Binocular?

A prism is the first invented prism in the 19th century by Ignazio Porro.

After his name, it was known as Porro prism. In Porro prism binoculars, they are aligned horizontally.

As a result, the light collection via the objective lens is passed through these horizontal directions.

Moreover, this prism is situated in the narrow barrel which is associated with the out objective lens.

This barrel gradually grows larger so that the Porro prism binoculars are a little bit bulky.

Besides, the zigzag shape of the Porro prism is useful for brighter output generation by amplifying the upside-down input and later inverting it to the correct orientation.

Top 5 Porro Prism Binoculars:

Image Features
Bushnell 10×50: (best value Porro prism binoculars)

Bushnell 10x50: (best value Porro prism binoculars)

  • Magnification – 10x
  • Objective Lens – 50mm
  • Exit Pupil – 5.0mm
  • Eye Relief – 10mm
  • Prism coating – BK-7
  • Lens – Fully multi-coated (FMC)
  • Material – Rubber
  • Dimension – ‎10.2 x 8.82 x 3.7 inches
  • Weight- 1.6 lbs

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Celestron G2 20×50: (best affordable Porro Prism binoculars)

Celestron G2 20x50: (best affordable Porro Prism binoculars)

  • Magnification – 20x
  • Objective Lens – 50mm
  • Eye Relief – 11mm
  • Prism coating – BK-7
  • Field of view – 168ft/1000 yards
  • Material – Metal
  • Water Resistance – Yes
  • Dimension – 7.3 x 6.3 x 32 inches
  • Weight- 1.75lbs

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Vortex Raptor 10×32: (best Porro prism binoculars under $100)

Vortex Raptor 10x32: (best Porro prism binoculars under $100)

  • Magnification – 10x
  • Objective Lens – 32mm
  • Material – Composite
  • Field of view – 339ft/1000 yards
  • Close focus – 15 ft
  • Water Resistance – Yes
  • Dimension – 7.75 x 7 x 3.5 inches
  • Weight- 2 lbs

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Tasco 10-30×50: (best Zoom Porro prism binoculars)

Tasco 10-30x50: (best Zoom Porro prism binoculars)

  • Magnification – 10-30x
  • Objective Lens -50mm
  • Eye Relief – 14mm
  • Lens coating – Fully coated
  • Field of view – 192ft/1000 yards
  • Water Resistance – Yes
  • Dimension – ‎10 x 9 x 4 inches
  • Weight- 26.4 ounces

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Brigenius 10×50: (Top reviewed Porro prism binoculars)

Brigenius 10x50: (Top reviewed Porro prism binoculars)

  • Magnification – 10x
  • Objective Lens – 50mm
  • Exit Pupil – 5.0mm
  • Material – Rubber
  • Prism coating – BAK-4
  • Field of view – 367ft/1000 yards
  • Water Resistance – Yes
  • Tripod adaptable – Yes
  • Dimension – 7.48 x 6.69 x 3.97 inches
  • Weight- 1.75lbs

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What is Roof Prism Binocular?

The basic identification or you can say it basic difference between roof and Porro is the glass placement.

The prism glasses are aligned straight in the roof prism binoculars.

As the light movement is amplified and then inverts not in a zigzag pattern, it will reduce the loss of light transmission.

And result in brighter and clear images.

So far, the roof prism binoculars are small and lightweight for the internal optimal construction.

Top 5 Roof Prism Binoculars:

Image Features
Gosky 10×42: (best overall roof prism binoculars)

Gosky 10x42: (best overall roof prism binoculars)

  • Magnification – 10x
  • Objective Lens – 42mm
  • Exit Pupil – 4.2mm
  • Lens Finish – FMC
  • Prism coating – BAK-4
  • Field of view – 306ft/1000 yards
  • Material – Rubber
  • Water Resistance – Yes
  • Dimension – 5.75 x 2.1 x 4.96 inches
  • Weight- 1.54 lbs

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Vortex 10×42: (best vortex roof prism binoculars)

Vortex 10x42: (best vortex roof prism binoculars)

  • Magnification – 10x
  • Objective Lens – 42mm
  • Exit Pupil – 4.2mm
  • Eye Relief – 16mm
  • Lens Finish – Multi-coated
  • Close Focus – 5feet
  • Field of view – 345ft/1000 yards
  • Material – Rubber
  • Water Resistance – Waterproof
  • Dimension – 5.9 x 5.6 x 1.75 inches
  • Weight – 1.5 lbs

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Gllysion 12×50: (best HD roof prism binoculars)

Gllysion 12x50: (best HD roof prism binoculars)

  • Magnification – 12x
  • Objective Lens – 50mm
  • Exit Pupil – 4.16mm
  • Eyepiece – 22mm
  • Prism coating – BAK-4
  • Field of view –
  • Material – Rubber
  • Water Resistance – IPX7 Waterproof
  • Dimension – 4 x 2.4 x 6.4 inches
  • Weight- 1pound

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C-eagleeye 10×42: (best compact roof prism binoculars)

C-eagleeye 10x42: (best compact roof prism binoculars)

  • Magnification – 10x
  • Objective Lens – 42mm
  • Exit Pupil – 4.2mm
  • Eye Relief – 21mm
  • Lens Finish – FMC
  • Prism coating – Bak-4
  • Material – Rubber
  • Field of view – 367ft/1000 yds
  • Water Resistance – IPX7 Waterproof
  • Dimension – 6 x 2 x 5 inches
  • Weight- 1.6lbs

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Leupold BX-2 10×42: (best waterproof roof prism binoculars)

Leupold BX-2 10x42: (best waterproof roof prism binoculars)

  • Magnification – 10x
  • Objective Lens – 42mm
  • Exit Pupil – 4.2mm
  • Prism coating – Bak-4
  • Material – Aluminum
  • Water Resistance – 100% Yes
  • Dimension – 8.23 x 6.57 x 3.43 inches
  • Weight- 1.75lbs

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Porro Prism vs Roof Prism Binoculars

Now, this span is for knowing the key differences between Porro and roof prism binoculars.

As you already know what they mean and how they are aligned, so their working principles must be varied.

Also, there will be differences in weight, size, performance, price range, and most importantly in the use cases.

They are also made for various outdoor activities though both types are not suitable for all activities so far. They have their strengths as well as limitations.

So, without any further delay, let’s jump into it.

1. Working Principle

When we concentrate on the internal part of the binoculars, we can easily distinguish which one is Porro and which one is roof prism. But how do they work inside the binoculars?

Well, the Porro prism has to rotate the magnified images in 180degrees and convert the axis in the opposite direction.

In terms of light transmission, they get the light through the rectangular face and reflect them 2 times internally via its zigzag pattern.

As a result, the binoculars can deliver a 3D image with better brightness and more depth perception.

On the other hand, the roof prism rotates the reflected lights from 90degrees faces 2 times. That will make a laterally flipped, bright, and clear image.

2. Performance

If you focus on the performance, the Porro prism is the winner. Besides, the Porro prism binoculars offer more field of view than the roof prism binoculars.

Moreover, the Porro prism’s working methods can deliver sharp, clear, and bright magnified images of the targeted objects.

Again, a roof prism is the best for water resistance capacity.

In that case, the Porro prism can’t provide a more protective barrier from water, dust, and moisture.

So, if you want more field of view, more perception of depth, and enhanced clarity then Porro prism binoculars are a good choice.

If you need something lightweight, with a narrow field of view with advanced weather protection, then roof prism binoculars can be on your bucket list.

See also – Nikon Prostaff 3s Vs 7s Binoculars: Which One is for You?

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3. Prims Coating

Prism has several types of coating to increase clarity as well as for protection purposes. The most common and popular coatings are the BAK-4 and BK-7.

They both have individual characteristics and functionalities but both work for the improvement of the performance of the prism.

Now the question is which lens coating is the best?

Well, the BK-4 is made of Borosilicate glasses whereas the BAK-4 is built from Barium Crown Glasses.

So far, the BK-7 is good for superior light transmission. At the same time, they are quite affordable too.

On the other hand, BAK-4 can maximize the light transmission higher than the BK-7 prism finish.

Also, offers edge-to-edge sharpness of the distance images.

Both types of coatings are used on Porro and roof prism binoculars.

I would recommend going for the BAK-4 prism to finish either its roof or Porro.

However, if you have a tight budget, then you can choose BK-7 prism binoculars.

4. Durability

If your main consideration is durability too with performance, then roof prism binoculars are worth choosing.

They are designed with portable size and outstanding build quality.

Also, they are mostly 100% waterproof whereas Porro prisms offer less protection.

At the same time, for their glasses placement, they are less durable than roof prism binoculars.

So, for a long hike, hunting, and whale observing, roof prism binoculars will perform well.

5. Weight

As I already mentioned, the weight of Porro prism binoculars is heavier than roof binoculars.

Because of their internal design, Porro prism binoculars look bulky. And the weight also increased at the same time.

However, the roof prism binoculars are lightweight and portable. You can see the difference in the above tables.

Moreover, for the heavyweight, there’s a chance of image shrinkage in the Porro prism binoculars.

So, I would recommend selecting roof prism binoculars for their compactness.

If you purchase a Porro prism, make sure it has a tripod mount system. That will make the pair stable as well as remove the chance of blurriness.

6. Price Range

What about the price range? You may wonder, but the price range of roof prism binoculars is quite more expensive than the Porro prism. Though you will get both Porro and roof prism binoculars even under $100. So, you can choose according to your budget after matching your all other requirements.

7. Purposes

The use cases can make a key difference between Porro prism vs roof prism binoculars.

When talking about binoculars, you must be aware of their prism type as well as their purposes. Otherwise, you won’t get the satisfying results anymore.

In my point of view, you can use Porro prisms for general outdoor activities, short time hiking or birding, hunting, etc.

As they have more field of view, you can also use them for wildlife viewing, spying, and peeing to look at your surroundings at a time.

Moreover, in low light conditions, Porro prism binoculars can be used to render bright images.

Again, for regular hiking, birding, stabilizing, sporting events, or for enjoying concerts, boating, daytime hunting, roof prism binoculars work very well.

As they are waterproof and lightweight, carrying and holding for an extended period won’t bother you too much.

Again, for the narrow field of view, you can use roof prism binoculars for precise target shooting.

Advantages of Porro Prism Binoculars over roof Prism

  • Offers more clear and bright images
  • Have a better perception of depth
  • Features large field of view


Heavy and bulky

Advantages of Roof Prism over Porro Prism Binoculars

  • Lightweight, compact and portable
  • Superior magnification system
  • Excellent waterproofing protection


Higher price range

Are Porro Prism binoculars any good?

Yes, Porro prism will deliver magnified images with superior clarity in a higher resolution.

Also, they have a wide field of view to observe a large area at a time.

What are Porro Prism binoculars used for?

Porro prism binoculars can be used for birding, hiking, hunting, spying even in dim light conditions, and many more.

Is BAK-4 A Roof Prism?

No. The BAK-4 is a glass type or prism coating for both roof and Porro prism.

Though the combination of roof prism and bak-4 coating will work like a bomb to generate outstanding output.

So, Which one you should choose: The final verdict

This entire session of comparison between Porro prism vs roof prism binoculars is for making your decisions narrower and more appropriate.

So, which one is the best for you? It is definitely up to your requirements, purposes, and budgets as well.

So far, my personal favorite is roof prism binoculars for their compactness, durability, and stunning image quality.

However, here I have differentiated their features, and performances along with their pros and cons. Now the decision is yours.

About James William

James William has completed his graduation on EEE from Stanford University. He is very fond of the mechanism of Binoculars. For his curiosity and passion, he joined our team and successfully played the chief editors role. He looks after the quality production of content. Also, he is very responsive to reviewing every piece of info and reviewing content about binoculars to provide the best content for you.

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