What Is a Mirrorless Camera and How Does It Work?

• What is a mirrorless camera?
• What’s the difference between mirrorless cameras and DSLRs?
• How does a mirrorless camera work?
• What are the drawbacks of mirrorless cameras?

Mirrorless cameras make up a new class of digital cameras intended to improve upon the DSLR camera design. While the first mirrorless cameras were not as powerful as DSLRs, recent models are matching and even outperforming DSLRs. To understand the impact of mirrorless cameras on digital photography and how it has transformed the world of interchangeable lens cameras, you need a comprehensive introduction to these cameras. A thorough comparison with DSLRs is also important to answer the question, are mirrorless cameras better than DSLRs?

While mirrorless cameras are popular among professional photographers, they might be new to many people taking up digital photography, so you may wonder what exactly a mirrorless camera is. Basically, it's a type of digital camera that doesn’t use a mirror or reflex lens. This difference gives it certain advantages over DSLRs and is the reason many amateur and professional photographers and filmmakers are embracing mirrorless cameras.

Without a reflex mirror and a pentaprism to redirect incoming light, a mirrorless camera has fewer components than a DSLR. While incoming light only reaches the imaging sensor in a DSLR when taking a shot, the imaging sensor in a mirrorless camera has light exposure all the time.

Lacking a reflex mirror is one of two key differences between a mirrorless camera and a DSLR. A mirrorless camera also doesn’t have an optical viewfinder. Rather, it uses an electronic viewfinder. These differences are responsible for most of the features worth mentioning when answering the question, what are the benefits of mirrorless cameras? With no reflex mirror and pentaprism, a mirrorless camera is a smaller and lighter professional digital camera than a DSLR. Because it has fewer moving parts, it’s quieter too.

While most mirrorless cameras have the mechanical shutter design of DSLRs, many also have electronic shutters that operate silently for those wishing to eliminate the telltale clicks of camera shutters. In summary, a mirrorless camera combines the advanced features of a DSLR with the portability and compact size of a point-and-shoot camera.

While they have different designs, mirrorless cameras and DSLRs both use interchangeable camera lenses. However, the pressing question many people getting their first professional cameras ask is, are mirrorless cameras better than DSLRs? Each camera type has its pros and cons. The design of a mirrorless camera gives it certain advantages over a DSLR. For example, since it lacks a mirror, there are fewer moving parts to cause camera shake while shooting. The smaller size of a mirrorless camera also makes it more portable.

With light consistently projected onto its image sensor, a mirrorless camera offers features such as face and eye tracking, zebra patterning and focus peaking. Therefore, mirrorless cameras are quicker at focusing on subjects and optimizing light exposure. Similarly, the electronic viewfinder in a mirrorless camera enables certain features, such as a live preview of depth of field and light exposure levels.

Video recording capability is another feature to consider because mirrorless cameras outperform DSLRs at shooting videos. While recording 4K videos is a feature mostly reserved for expensive, high-end DSLRs, most mirrorless cameras – even the entry-level ones – can shoot 4K videos. Mirrorless cameras also have faster shutter speeds and deliver better image stabilization.

However, it’s also important to know areas where DSLR cameras outperform mirrorless models. DSLRs drain batteries more slowly and enjoy a richer selection of lenses and accessories. These differences make them more versatile for extended photoshoots. To help bridge the gap in accessories options between the two types of cameras, there are adapters for mounting DSLR lenses on mirrorless camera bodies.

It’s important to know how a DSLR works to understand how a mirrorless camera works and appreciate its simpler mechanics. A DSLR camera requires eight key components to take a photo. These are interchangeable lenses, a reflex mirror, a focusing screen, a condenser lens, a pentaprism, an optical viewfinder, a shutter and an image sensor. Incoming light passes through each of these components to the optical viewfinder when framing a shot, and then through the shutter to the image sensor when taking a picture.

In contrast, a mirrorless camera needs only four components to take a photo. While it also uses an interchangeable lens, a shutter and an image sensor, it eliminates other components and substitutes the optical viewfinder with an electronic one. Incoming light from the interchangeable lens goes directly to the image sensor after passing through the shutter. Then the electronic viewfinder sees the image and projects it with the sensor onto the LCD screen to help frame the shot.

For all their advantages, mirrorless cameras are not without certain drawbacks. Mirrorless cameras drain batteries faster than DSLRs, as they need constant power for their LCD screens and electronic viewfinders. In contrast, the optical viewfinder in a DSLR doesn’t draw power. A shorter battery life means a mirrorless camera isn’t great for long photoshoots. For extended photography sessions, you’ll need to have spare batteries handy in your camera bag. Get rechargeable batteries to spend less on keeping your power-hungry mirrorless camera running.

With its smaller lens selection, a mirrorless camera may not be as adaptable as a DSLR for certain types of photography. Professional photographers expect that, with time, the variety of lenses available for mirrorless cameras will match the rich lens selection for DSLRs.

Lastly, while high-end mirrorless cameras and DSLRs have comparable prices, entry-level mirrorless cameras cost more than entry-level DSLRs that have impressive features for their price. With these drawbacks, beginners and amateur photographers are more likely to choose DSLRs.

In summary, a mirrorless camera is a simpler, lighter and quieter professional camera that rivals a DSLR in performance. Understand its advantages over a DSLR and its limitations before deciding to buy a mirrorless camera.