What is a Mirrorless Camera?

Mirrorless cameras have been on the market for a decade, but they have really begun to make waves in the past few years. Most serious photographers would have certainly been shooting with a DSLR camera just a few years ago, but now many have traded in their DSLRs for the smaller and lighter form factors that mirrorless cameras provide. Not only are mirrorless cameras usually lighter and smaller than their DSLR counterparts, but they’re quieter, as well. With no mirror to slap up and down, street photographers, as well as wedding and theater photographers can now shoot virtually unnoticed.

Choosing a mirrorless camera can be a daunting task with lots of options, from sensor size, to video capabilities, to lens systems, and more. We will cover them all, and give you the information you need. Buying your new camera should be an exciting experience, so let this guide help you make an informed decision.

Lens Systems      

What differentiates mirrorless cameras from other compact cameras is the fact that they have interchangeable lenses. This makes a world of difference, and if you’ve never had an interchangeable-lens camera, you will be quite surprised by how it will change your photography.

Compact point-and-shoot cameras have a built-in lens that typically gives you an optical zoom with a variable aperture and small sensor. What this means is that while you might have the ability to shoot both wide and telephoto zoom lengths, you don’t have as much control over selective focus or shallow-depth-of-field techniques. Selective focus, often accentuated by pronounced bokeh, is one of the first things that people notice about photos taken with larger sensor, interchangeable-lens cameras, because now you have the option to shoot with a long zoom lens with an f/2.8 aperture, or a prime portrait lens with an f/1.4 aperture.

Sample shots were taken with a GH4 and SLR Magic HyperPrime CINE 25mm T0.95 lens.

A good thing about mirrorless cameras is that because there is no mirror inside the camera in front of the sensor, their design allows for a very short focal flange distance, or the distance between the lens mount and the plane of the sensor. Because of this short distance, lenses that have a large focal flange length can be used on mirrorless cameras when you have a compatible adapter.  This means that, in addition to a wide selection of mirrorless-dedicated lenses, most SLR lenses can also fit onto your mirrorless camera as well.  This is important to know if you have a bunch of old lenses lying around or are making the switch from a DSLR to mirrorless; chances are there are adapters to fit your lenses to your new camera. Of course, you should always check compatibility before making any purchases.

While using older “legacy” lenses on a mirrorless camera is a great benefit, every pro has a con and, in most cases, the downside in this situation is that the adapters usually do not allow for autofocus capabilities, and sometimes do not transfer any electronic signals at all, so aperture must also be set manually. This can be a drawback for some photographers, but for videographers who normally change aperture and focus manually, this isn’t a drawback at all. 

Maybe you don’t have any lenses from other cameras, or you want to sell them all and forget about adapters. In that case, there is certainly no shortage of great lenses designed specifically for mirrorless cameras. Due to increasing attention to mirrorless systems, manufacturers have invested a great deal into providing a wide variety of lenses, from fast prime lenses to wide-to-tele zoom lenses. Whatever you are looking for in a lens, chances are you can find it in a mirrorless line.

Sensor Size

Different mirrorless cameras come with various-sized sensors, and this is where things can get a little confusing. To make things simple, think of a full-frame DSLR camera as having the largest sized sensor, and a point-and-shoot as the smallest sized sensor. Most mirrorless cameras fall somewhere in the middle, packing an APS-C sensor, which is common in consumer DSLR cameras, or a Micro Four Thirds sensor, which falls between an APS-C sensor and a point-and-shoot. While they are the minority, there are now a few cameras that do have a full-frame sensor, and there will probably be more to come in the future.

Micro Four Thirds cameras feature a 17.3 x 13mm sensor, and are most commonly made by Panasonic and Olympus. Both manufacturers use the same mount, as part of the Micro Four Thirds standard, so lenses are interchangeable between brands. Olympus usually utilizes in-camera stabilization, while Panasonic tends to have their stabilization in the lenses. However, Panasonic has recently begun to utilize in-body image stabilization in some models, as well.

A little bit smaller than the Micro Four Thirds sensors are the Nikon 1 (CX format) and Pentax Q series cameras, which use sensors closer to the size of point-and-shoot cameras—1" for the Nikon 1, 1/1.7" or 1/2.3" for Pentax Q—allowing these lines to be much more compact than other mirrorless cameras.  

A significant reason that some people like mirrorless cameras is that they are smaller and lighter than DSLRs, and a lot of that has to do with the smaller sensor size. While a smaller and lighter camera is great for some, it, too, has a drawback. Generally speaking, larger sensors perform better in lower light, and produce less image noise in photos taken with higher ISO sensitivities. If low-light photography is important to you, you might want to consider one of the full-frame mirrorless cameras, or at least one with an APS-C sized sensor. If you are more concerned with a smaller camera size, and don’t require the best in low-light performance, a Micro Four Thirds camera might be a good fit for you. This is not to say that cameras with smaller sensors are not suitable for low-light shooting, rather, it is one of the main benefits of a larger sensor size.

Sample shots were taken with a GH4 and SLR Magic HyperPrime CINE 25mm T0.95 lens.

Viewfinders

Viewfinders are another thing to take into consideration, particularly if you’re switching from a DSLR or other type of camera that has an optical TTL (through-the-lens) viewfinder. A TTL viewfinder means that what you are seeing is exactly (or very close to) what the lens is seeing. Since, by design, there is no mirror to direct the view of the lens to the viewfinder, many mirrorless cameras utilize an electronic viewfinder, or EVF.

There are, of course, benefits and disadvantages to the EVF, just as there are for an optical viewfinder. One thing that can be distracting is that touch of lag time between the moment that something is actually moving and the time that you see it in the EVF. As technology improves, this lag time is becoming shorter and shorter and, in some cameras, is already imperceptible.

Another disadvantage is that an EVF eats away at your battery power, just as using your LCD screen would. This is minimal, and usually not a huge concern, but just another thing to take into consideration.

As for advantages, there are quite a few, the first of which is focus peaking, which has become a desirable asset when comparing cameras for video or manual-focus uses. Focus peaking is a real-time focusing aid that highlights edges of contrast within the frame with a colored line, which helps to avail a more objective system of determining critical sharpness when focusing manually.

Focus Peaking

The other main advantage an EVF has is its ability to give an accurate depiction of any exposure, color balance, or other camera-setting adjustments prior to shooting. Whereas an OVF simply displays the subject as it is, an EVF gives you a closer representation of the final image.

Autofocus

DSLR cameras use what is called phase detection to focus on a subject, while mirrorless cameras use contrast detection. Phase detection takes advantage of the mirror in a DSLR camera to divide the incoming light into pairs of images, compares them, and then quickly focuses the lens on the subject.

Mirrorless cameras, on the other hand, use contrast detection to measure the contrast between pixels on the sensor until it detects enough contrast to find that the image is in focus. The downside of this focusing method is that it is slower, and more difficult to use in low light. It is also less effective when trying to focus on moving objects.

The good news for mirrorless shooters is that many newer cameras are now using a hybrid focusing method that combines phase- and contrast-detection methods. This is another consideration to weigh before choosing your camera. If fast autofocus, especially in low light, is important to you, you should consider a camera with a hybrid autofocus system.

Video

Video recording is one area where mirrorless cameras and DSLR cameras are pretty much neck and neck, when it comes to quality. Of course, mirrorless cameras are going to offer video shooters more flexibility with lenses than DSLR cameras, but both systems offer cameras that can shoot full HD, and some cameras can also now shoot 4K.

Get the most out of 4K video recording by connecting your mirrorless camera to a 4K recorder/monitor.

What mirrorless cameras improve upon, compared to many DSLRs, is the way they shoot, not necessarily what they can shoot. Because mirrorless cameras focus with continuous contrast-detection, you can more easily focus, and maintain focus, on moving subjects in your frame. DSLRs also utilize contrast-detection focusing when recording movies, or when working in live view, but since it is the inherent technology within a mirrorless camera, it is often more refined and responsive.

If you’re making the move up from point-and-shoot cameras to a mirrorless, then the video quality is going to be leaps and bounds better than what you’re used to. For one thing, you will be able to control the depth of field via the aperture, and also manually focus your shot. This gives you greater creative control, not to mention much higher-quality files.

The smaller size of mirrorless cameras means that the camera’s light weight allows for longer shooting with less fatigue than shooting video handheld with a DSLR camera.

If you are a serious videographer and want professional video capabilities, you might consider a mirrorless camera that records video in a high-quality format, such as AVCHD or XAVC S, and one with which you can use external microphones, headphones, video monitors, and recorders.

Wireless Functionality

The wireless capabilities that have been included in many of the mirrorless cameras on the market are truly incredible. Most cameras with Wi-Fi also have a partner app for either iOS or Android that allow you to control the camera from a smartphone or tablet.

NFC allows cameras to “bump” each other, or another smart device, to share photos.

These apps range from basic live view and shutter control, to full control over shutter speed, aperture, ISO, and other settings that you would normally need to adjust on the camera.

Some cameras enable you to transfer images directly to a smart device from your camera, or even right to your favorite social media sites. Another great Wi-Fi function is Near Field Communication, or NFC, which allows cameras to tap-to-connect with one another or a smart device, to share photos. This is especially helpful when you’re with friends and you want to share photos without having to remember to email them later.

Choosing Your Mirrorless Camera

By now you should be able to make an informed decision about buying your next camera. Keep in mind the main points we discussed. If image size and quality, especially in low light, is important to you, choose a camera with either an APS-C or full-frame sensor. However, if you’re looking for a compact camera that offers more control and options than a point-and-shoot, choose one of the cameras with a smaller sensor.

Most mirrorless cameras will fall into one of three categories: consumer, prosumer, and professional. This doesn’t mean that a professional camera will guarantee professional-looking photos, rather, that it is built with the capabilities that professionals need and want.

Consumer

Entry-level consumer mirrorless cameras are a great starting point for someone looking to make a move from point-and-shoot cameras to something with a little more flexibility and control. Often, entry-level mirrorless cameras are a replacement for consumers who are using an entry-level DSLR and like the interchangeable-lens feature, but want something that is lighter and smaller. These cameras usually offer an LCD to compose your photos instead of an electronic viewfinder. Consumer-level mirrorless cameras typically have a smaller sensor, allowing for a smaller and lighter body size, while sacrificing a little bit of image quality.

Prosumer

In between consumer and pro cameras are “prosumer” cameras. In the world of mirrorless cameras, prosumer-level cameras will probably be most comfortable for photographers making the move from a DSLR to a mirrorless model. Prosumer cameras have a slightly smaller body size than professional-level cameras, while offering more control and better image quality than consumer cameras.

Another thing that makes prosumer mirrorless cameras appealing is that many of them have an electronic viewfinder, as well as the LCD screen on the back of the camera. This makes the transition to mirrorless much easier if you are accustomed to looking through an optical viewfinder. With both an EVF and an LCD screen, problems with viewing your composition in bright light are minimized.

Professional-Level Cameras

If the highest-quality video and imagery is what you seek from a mirrorless camera, a professional-level camera will deliver what you need. These cameras straddle all formats, including Micro Four Thirds, APS-C, and full-frame and also tend to feature larger, more durable bodies that are often weather sealed. Additionally, they are characterized by faster processors, which aid autofocus performance and buffering when shooting large files or burst sequences. These cameras are also ideal for shooting professional videos, thanks to their support for external monitors, headphones, and microphones, as well as external video recorders.

These are the cameras that you will want to consider if you are an advanced hobbyist or professional who is used to the feel and performance of a professional DSLR camera. They offer the most creative control through their inclusion of fully manual adjustment capabilities and support for interface customization. Additionally, professional-grade cameras are usually the preferred choice when working in adverse situations, such as extreme low lighting or fast-action situations, due to their expanded imaging capabilities, sensitivity, and refined focusing performance.

After you choose your preferred sensor size or system type, think about what kind of lenses you might already own, or what types of lenses exist for the various cameras you are considering. Some manufacturers have a wider line of lenses for their mirrorless cameras than others, and this might be important to you if you like options.

Once you have narrowed down the larger, important aspects of choosing your camera, take a look at what features are important to you. Do you need HD or 4K video? Maybe you are a social-media guru and really like the ability to share photos online directly from your camera.

Another consideration is the accessories that are available for the various cameras. If you use an external flash, you’re going to want to make sure compatible flashes are available, and that the camera has a hot shoe to which one can be attached. Other accessories that might be important are battery grips, cases, remote controls, and apps―just to name a few.

You should now be prepared to choose the mirrorless camera that best suits your needs. Of course, if you have any questions, feel free to stop by the B&H SuperStore in New York, speak with a sales professional on the telephone at 1-800-606-6969 or contact us online for a Live Chat.