What Are Roof Prisms in Monoculars? – Complete Breakdown

People often ask, what is roof prisms in monocular

Let’s find out!

What Is Roof Prisms in Monocular?

Roof prisms are used to correct for the optical distortion that occurs when a person looks at an object from above.

The roof prism is essentially a pair of lenses placed on either side of your eye, which allow you to see objects as they would appear if viewed straight down. This type of lens is commonly referred to as a “monocular” or “single-lens reflex camera”.

What Is The Difference Between A Porro Prism And A Roof Prism Binocular?

A Porro prism binoculars uses two lenses with different focal lengths (the distance between the front surface of the lens and the back surface). This allows the user to see objects from a wider angle than if only a single lens were used. In this case, the image is split into two images by the two lenses.

A roof prism binoculars uses a single lens with no splitting of the image. Instead, the image is transmitted directly through the lens to the eye.

So which one should you buy? It depends on your needs. If you want to use them for birding, hiking, fishing, etc., then a roof prism will be more suitable because it can provide a wider field of view. However, if you just need something to watch TV or play games, then a Porro prism might be better suited.

How Do They Work Together?

When you look through a pair of binoculars, the image is formed by the combination of the objective lens and the eyepiece. The objective lens focuses an object onto the retina of the eye. The eyepiece refracts the focused image so that it appears larger.

In a Porro prism binocular, the objective lens and the ocular lens are separate pieces. Because there are two lenses, the image is split before reaching the eye. This results in two images being seen simultaneously.

When you look through a roof prism binocular, the image is not split. Instead, the image passes straight through the objective lens and eyepiece.

Which One Should You Buy?

If you plan to use your binoculars for bird watching, hiking, fishing, or any activity where you’ll need a wide field of view, then a roof prism would be best. Otherwise, if you just want something to watch TV or a game, then a Porro would be better.

what is roof prisms in monocular

What Are Roof Prisms in Monoculars?

Olympus Monocular Review

The Olympus OM-D E-M1 Mark II is a new addition to the Olympus lineup of mirrorless cameras. It’s an interesting camera, and one that we think will be very popular with photographers who want a compact system camera but don’t want to sacrifice too much in terms of image quality or features.

The OM-D E-m1 Mark II has some great features, including a 16MP sensor, 4K video recording, full HD 1080p video recording at 60fps, dual SD card slots, Wi-Fi connectivity, built-in GPS, and a 3 inch tilting LCD screen. But does it live up to its potential? Let’s take a closer look.


  • Prism TypeRoof
  • Magnification6x
  • Objective Lens Diameter16 mm
  • Angle of View8° (Actual)
  • Field of View420′ @ 1000 yd / 140 m @ 1000 m
  • Minimum Focus Distance4.9′ / 1.5 m
  • Exit Pupil Diameter2.7 mm
  • Eye Relief11.5 mm
  • FogproofYes, Nitrogen Filled
  • Water ResistanceWaterproof
  • Dimensions3.4 x 1.5 x 1″ / 8.7 x 3.8 x 2.5 cm
  • Weight2.5 oz / 70 g
  • Package Weight0.27 lb
  • Box Dimensions (LxWxH)4.9 x 2.4 x 1.95″

Objective Lenses

The OM-D E- M1 Mark II comes with three interchangeable objective lenses: 12mm f/2.8, 14mm f/2.0, and 17mm f/1.8. These lenses have been designed specifically for the OM-D E- m1 Mark II. Each lens offers a unique perspective and performance.

For example, the 12mm f/2,8 provides excellent corner sharpness and contrast while maintaining good resolution across the frame. On the other hand, the 14mm f/2 offers a slightly softer bokeh effect, making it ideal for portraits.

And finally, the 17mm f/1,8 delivers exceptional detail and color accuracy. All three lenses feature a circular aperture diaphragm, allowing for smooth out-of-focus highlights


The OM-D EM-1 Mark II uses a 6X optical zoom lens. That means that when you zoom in on an object, you get six times as many pixels as what you see without zooming in. In fact, this is the highest magnification ratio available on any digital SLR.

So, if you’re looking for maximum clarity, you can’t go wrong with the OM-D E -M1 Mark II’s 6X optical zoom.

Optical Image Stabilization

The OM-D Mark II also features Optical Image Stabilization (OIS). OIS helps reduce blur caused by camera shake. When you hold the camera still, OIS works automatically to compensate for movement. If you move the camera even slightly, OIS compensates for the motion so that you get sharper images.

Automatic Exposure Control

The OM-D Mark II features automatic exposure control (AEC), which allows you to shoot in a variety of lighting conditions.

AEC automatically adjusts the shutter speed and ISO sensitivity settings to ensure proper exposures.

You can choose from five different modes: Programmed auto, Scene Intelligent Auto, Creative Auto, Landscape, and Sports.

Focus Distance

The OM-D M1 Mark II focuses down to 4.9 feet (1.5 meters) away from your subject. This focus distance is equivalent to about 28 inches (70 centimeters) when shooting at infinity.

Image Sensor

The OM-D Em-1 Mark II features a 16-megapixel APS-C size CMOS sensor. This sensor captures more light than most competing models, resulting in better low-light performance. And because the sensor is smaller, the camera doesn’t need as much power to operate.

Field of Vision

The OM-D em-1 Mark II has a 420-degree wide-angle field of view. With this wide angle, you can capture a lot of the scenes around you.


The OM-D Mark II is equipped with a tilting LCD monitor. The screen tilts up or down 90 degrees. This makes it easier to compose shots from awkward angles.


The OM-D e-M1 Mark II is built tough. It’s made from magnesium alloy, making it lightweight and durable.

Battery Life

The battery life of the OM-D EEM-1 Mark II is rated at approximately 300 shots per charge.

Storage Capacity

The OM-D D-EEM-1 Mark II includes a 2GB SD memory card. This card will store approximately 1,200 RAW files.


The OM-D EEM1 Mark II supports Wi-Fi connectivity. This lets you share photos wirelessly using your smartphone or tablet.

Other Features

The OM-D D-EM1 Mark II comes with a number of useful accessories. These include a protective case, a USB cable, a remote release, a tripod adapter, a wrist strap, and a cleaning kit.


We hope that this article was helpful. If you have any queries feel free to reach out in the comments section below.


  • John Moses

    John is the Editor in Chief here at The Outdoor Stores. His area of expertise ensures that there is no one better to suggest which rifles are most suitable for your hunting experience. He is also available for you to contact him personally to discuss the types of animals you want to hunt and the terrain you will be hunting on. Feel free to read his posts for expert opinion on Rifles, Scopes, Rangefinders, Bonoculars and Monoculars.

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