Advantages of Mirrorless Cameras

Mirrorless cameras have become increasingly popular. They’re aimed at compact camera users who want DSLR image quality and interchangeable-lens versatility in a compact package, as well as at advanced and pro shooters looking for a lighter alternative to their big pro cameras. A goodly number of pros have a mirrorless camera as a backup or for when they want to travel light. But can a mirrorless system replace a DSLR system for a pro entirely?

Obviously, current mirrorless cameras aren’t ideal for some things, such as handheld long-lens and fast-action work. But their combination of image quality, excellent motion-capture ability and the availability of excellent optics makes them viable for many professional photography endeavors. Depending on what you do, mirrorless models might be able to step out from the shadows of backup status and move into the primary starter role—if you give them the chance. We’ve outlined some key criteria here and the top models from several manufacturers that you might consider for a move to mirrorless. For inclusion in this article, we required that a camera have an eye-level finder. We feel this is a necessity for professional work. This eliminated some cameras that would make fine backups. For primary use, an eye-level finder that you can reliably use in any conditions is essential.

Low-Light Capability

Using the same sensors, today’s mirrorless cameras can deliver high-ISO image quality equal to that of the best DSLRs with same-sized sensors (i.e., APS-C or Four Thirds). However, full-frame sensors can deliver better high-ISO image quality, and as cited, as of this writing we have no full-frame mirrorless interchangeable-lens cameras except the rangefinder Leica M Typ 240 (which rates 10th in low-light ISO scores among current full-frame cameras in’s sensor ratings). So, again, if you specialize in low-light work, a full-frame DSLR is your best bet today.

Image Quality

Mirrorless cameras are certainly capable of delivering professional image quality. Most have APS-C or Micro Four Thirds image sensors, and deliver images equivalent to those of DSLRs of equal sensor size and pixel count. Pixel counts of current mirrorless cameras are in the 16- to 24-megapixel range, with sensor ratings similar to those of same-format DSLRs produced by the same companies—as would be expected, since mirrorless cameras and DSLRs use essentially the same sensors.

We haven’t seen a full-frame mirrorless interchangeable-lens camera yet, but Sony’s RX1 and RX1R show it’s possible to put a full-frame sensor in a tiny body (4.5×2.6×2.7 inches, 16.0 ounces, including a built-in 35mm ƒ/2 lens). And Sony has for some time been rumored to have a full-frame mirrorless model in the works. (Leica’s M Typ 240 is a full-frame rangefinder—and thus mirrorless camera—with an accessory electronic viewfinder available, but focal-length range is limited to 16mm through 135mm.) So, for now, most applications requiring a full-frame sensor and interchangeable lenses are best done with a full-frame DSLR.

Focus Performance

The first mirrorless cameras had very slow AF. That’s because they use contrast-based AF, which requires several readings to determine and set focus, while the phase-detection systems in DSLRs can theoretically do it in a single reading. Despite this slowness, mirrorless cameras were still faster than DSLRs in Live View mode because the DSLRs had to use contrast-based AF in live view, including video, and this wasn’t implemented well.

Today, new technology has sped up mirrorless AF performance. Contrast-based systems now read at 240 fps instead of 60 fps. Hybrid systems use phase-detection AF to quickly ballpark focus, then contrast AF to fine-tune it. Contrast AF can be more accurate than phase detection because it works right off the image sensor, while traditional DSLR phase-detection uses mirrors that have to be precisely aligned for accurate results. Recently, Canon introduced (in its EOS 70D DSLR) an on-sensor phase-detection system that looks promising and could be used in a future mirrorless camera, while the on-sensor phase-detection system in the upcoming Olympus OM-D E-M1 mirrorless model also looks promising.

Phase-detection AF is better at tracking subjects moving toward or away from the camera than contrast AF, so for the moment, DSLRs are a better choice than mirrorless cameras for pro-level action shooting (pro DSLR action lenses are also better suited for such work than mirrorless lenses). The Nikon 1 mirrorless cameras have a hybrid phase/contrast AF system that works well on action subjects, but aren’t included here because they’re based on a smaller-than-DSLR image sensor and thus deliver less-than-DSLR image quality, with sensor scores in the low to mid-50s versus the mid-60s to low 80s for current APS-C mirrorless cameras. Hybrid systems and new on-sensor phase-detection systems will bring mirrorless AF performance up to pro level, but right now, DSLRs still have the edge for action with pro image quality.

Dim light has always been a problem for phase-detection and contrast-based AF systems, and at first, phase-detection handled it better. Recent contrast-based systems have narrowed the gap.

Many mirrorless cameras offer touch-screen focus control. Just touch the point in the image on the LCD monitor where you want the camera to focus, and it will focus there. This can be handy for video, as well as odd-angle still photography.

Many find mirrorless cameras easier to focus manually than DSLRs because the mirrorless models provide magnified viewing and focus peaking (which highlights the focused areas in color), while DSLRs have focusing screens designed for AF, not for manual focusing. On the other hand, with most mirrorless cameras, manual focusing is electronic, not mechanical. When you turn the focusing ring or other focusing control, it activates a motor that moves the lens; this eliminates the direct feel and precision of mechanical manual focusing.

HD Video

Mirrorless cameras actually have better video capabilities than most DSLRs because their AF systems are faster than typical DSLRs in Live View/Video mode. Of course, the camera’s built-in microphone will pick up the sound of the AF motor, so it’s wise to use an external mic or focus manually, or both. Many mirrorless cameras offer touch-screen AF, where you can change focus to any point in the scene just by touching it on the LCD monitor; this can be very useful for racking focus in a scene.

All current mirrorless cameras can shoot 1080 full HD video. Panasonic’s Lumix DMC-GH3, GX7 and G6 and Sony’s NEX-7, NEX-6 and NEX-5T can do it at 60p, Olympus’ OM-D E-M5 and Sony’s new ILC-A3000, at 60i; other Olympus models and Samsung’s NX20 record at 30p, and Fujifilm’s X-Pro1 and X-E1, at 24p. The 60 fps cameras can also shoot at slower rates. And like DSLRs, mirrorless cameras can shoot video at lower resolutions (720p, VGA), too.

It’s hard to shoot steady video holding the camera out at arm’s length, so you definitely want an eye-level finder for handheld video work. Steadiest results will come from using a tripod, but that negates one of the mirrorless camera’s main advantages over a DSLR: compact size.


DSLRs (except Sony’s SLT fixed-mirror models) have eye-level optical viewfinders that provide clear through-the-lens viewing and are familiar to veteran photographers. Mirrorless cameras, having
no SLR mirror, use electronic viewfinders for eye-level viewing (about half of today’s mirrorless models either have built-in EVFs or have one available as an accessory). Of course, DSLRs and mirrorless cameras have large external LCD monitors, as well; the ones that tilt and swivel are especially useful for odd-angle shooting.Early electronic viewfinders weren’t very good, but today’s better ones are very good—better than the pentamirror optical finders in entry-level DSLRs. EVFs can display lots of data, including live histograms and a preview of white balance and other effects. But the fact that they don’t provide a continuous view, but rather a high-frame-rate video one, makes them less effective than DSLR optical finders for action and panning shots. But as EVF technology continues to evolve, we expect that electronic viewfinders eventually will replace optical finders on most cameras.

Lens Options

DSLRs have been in production longer than mirrorless digital cameras (the first of the latter was introduced in late 2008), and many DSLRs were based on the manufacturer’s 35mm film SLR systems, so there’s a wider range of lens focal lengths available for DSLRs today. But mirrorless lens lines are expanding regularly and have the advantage of all being designed specifically for digital and the format of their cameras. Additionally, because mirrorless cameras have very short flange-back distances (the distance between the lens mount and the sensor), pretty much any lens for which an adapter can be found can be used on mirrorless cameras (with manual focusing, in most cases).

Fujifilm currently offers seven Fujinon X-series lenses for its X cameras, from a 14mm through a 55-200mm zoom, providing 35mm-camera-equivalent focal lengths from 21mm through 300mm. Several of the lenses incorporate OIS optical image stabilization.

As Micro Four Thirds cameras, Olympus and Panasonic mirrorless models can use all MFT lenses and just about any lens for which an adapter can be found. Current Olympus MFT lenses range from a 9-18mm zoom through a 75-300mm zoom, providing (thanks to the MFT sensor’s 2.0X crop factor) 35mm-camera-equivalent focal lengths from 18mm through 600mm. Panasonic currently offers 22 lenses, from a 7-14mm to a 100-300mm, providing 35mm-camera-equivalent focal lengths from 14mm through 600mm, including a fisheye and a 3D lens. Olympus mirrorless cameras provide in-body sensor-shift image-stabilization, and thus their lenses don’t offer it. Many Panasonic lenses have in-lens OIS (Optical Image Stabilization)—if you use one on an Olympus body, switch off one of the stabilization systems.

Samsung offers 12 NX-mount lenses, which currently number 12, ranging from a 12-24mm to an 18-200mm and a 55-200mm, and thus providing 35mm-camera-equivalent focal lengths of 18mm through 300mm. Samsung’s i-Function lets you access a number of functions via the focusing ring on i-Function lenses. The 45mm ƒ/1.8 2D/3D lens produces 3D stills and video that can be viewed on 3D-capable TVs and compatible devices.

Sony offers 12 native E-mount lenses for its NEX cameras (and the new ILC-A3000), from 10-18mm through 55-210mm, providing 35mm-camera-equivalent focal lengths from 15mm through 305mm. The LA-EA2 adapter lets you use Sony A-series and legacy Konica Minolta lenses and provides phase-detection AF with them. Some of the lenses feature Optical SteadyShot image stabilization, handy since the NEX cameras don’t have in-body sensor-shift stabilization.


Today’s mirrorless cameras start up and wake up from sleep mode comparably to equivalent-priced DSLRs, and button-pushing-to-image-recording times are very quick. Two things to consider, though, are frame rate and buffer size, and in both of these areas, DSLRs have an advantage. Some mirrorless cameras show very quick frame rates in their spec sheets, but you have to check whether these are for full-resolution images and whether the camera focuses for each frame. Often, the rate for full-res images with AF for each shot is slower than equivalent DSLRs and certainly slower than pro DSLRs. Also, mirrorless cameras have relatively small buffers; you can only shoot a few shots at the top frame rate compared to a higher-end DSLR.

Fujifilm X-Pro1


Top Pro-Worthy Mirrorless Cameras

Fujifilm X-Pro1. The X-Pro1 added interchangeable-lens capability to the features of the popular X100 camera. The beautiful, rugged and functional design and unique hybrid viewfinder now can be used with focal lengths from 14mm through 200mm (equivalent to 21mm through 300mm on a 35mm camera).

The 16.3-megapixel APS-C Fujifilm X-Trans image sensor features a unique RGB filter array that differs from conventional Bayer arrays by using a more random arrangement that positions red, green and blue pixels in every horizontal and vertical row. This minimizes moiré and false colors, allowing Fujifilm to do away with the sharpness-robbing optical low-pass filter required by Bayer-array cameras.

The Hybrid Multi Viewfinder lets you easily switch the eye-level finder between optical and electronic, as desired. Optical mode minimizes shutter lag and provides brighter viewing, while electronic mode provides a live-view image. Both display lots of information, including a virtual horizon, distance data and a histogram. You can also use the crisp, 3.0-inch 1230K-dot external LCD monitor for composing images.

Aperture rings let you make settings in precise 1⁄3-step increments, while dials atop the camera provide direct setting of shutter speeds and exposure compensation, and resist inadvertent turning.
AF is contrast-based. There’s no manual focus-peaking (the new X-M1 has it, but no eye-level viewfinder). Video capabilities include 1080 and 720 at 24p, with stereo sound. Estimated Street Price: $1,199 (body only).

Olympus OM-D E-M5

Olympus OM-D E-M5. The “mini-DSLR”-style OM-D E-M5 features an excellent 16.1-megapixel Micro Four Thirds image sensor and a sturdy, lightweight magnesium-alloy body with dust- and splashproof sealing like Olympus’ E-5 pro DSLR. While not all m43 lenses are splashproof, the M.Zuiko Digital ED 12-50mm ƒ/3.5-6.3 EZ kit zoom is, as are the provided FL-LN2 flash unit and optional HLD-6 Power Battery Grip and MMF-3 Four Thirds lens adapter.

Building on the superquick FAST (Frequency Acceleration Sensor Technology) contrast-based AF system introduced in the PEN E-P3, the OM-D E-M5 doubles the speed (now 240 fps off the sensor), providing a shooting rate of 4.2 fps with 3D tracking AF that can follow a moving subject through X, Y and Z axes (and 9 fps with focus locked at the first frame). There’s also five-axis sensor-shift image stabilization that works for still and video shooting with all lenses, and counters horizontal and vertical shift, plus roll, yaw and pitch motions.

A 1,440,000-dot electronic view-finder provides convenient eye-level operation, while a tilting 3.0-inch, 610,000-dot rear OLED monitor offers touch-screen AF and odd-angle shooting. A handy mode dial provides easy access to shooting modes, Art Filters, video and more.

The OM-D E-M5 can record 1920×1080 full HD and 1280×720 HD MOV (MPEG-4 AVC/H.264) video at 60i (59.94 fps), and 1280×720 HD and 640×480 SD AVI (Motion JPEG) video at 30 fps. You can shoot video in program, shutter-priority, aperture-priority or manual mode, and apply special effects. A buil
t-in microphone provides stereo sound recording. Estimated Street Price: $999 (body only).

Panasonic Lumix DMC-GH3

Panasonic Lumix DMC-GH3. Panasonic’s top-of-the-line mirrorless model, the Lumix DMC-GH3 provides a rugged, dust- and splash-proof magnesium-alloy body that’s a bit larger than its predecessor’s for easier video shooting. The 16.05-megapixel Live MOS image sensor delivers improved still image quality, as well as new video capabilities. Normal ISO range is 200-12,800, expandable to 125-25,600. The GH3 can shoot full-res images at 6 fps (4 fps with live view) and 4-megapixel images at 20 fps. Contrast-based Light Speed AF exchanges data at up to 240 fps between body and lens for superquick performance for stills and video.

Panasonic’s GH cameras have been noted for their video capabilities. The GH3 expands on them. It can shoot MOV (H.264) 1080p at 60, 30 and 24 fps and 720p at 60 fps, 50 Mbps with IPB compression and 72 Mbps with Al-Intra compression. It can also shoot AVCHD Progressive at 1080/60p and AVCHD 1080 at 60i and 24p—all with SMPTE timecoding, if desired. It can also shoot MP4 1080p, 720p and 480p video at 30 fps. The camera is designed to disperse heat for longer run times. Built-in microphones record stereo sound, and there’s a 3.5mm external microphone jack, plus a headphone jack.

A 1774K-dot OLED Live View Finder provides handy eye-level still and video shooting, while the free-angle 3.0-inch, 640K-dot OLED touch-screen monitor offers easy odd-angle shooting and autofocus-point selection. A flash-sync socket lets you connect studio flash systems. There’s also a built-in flash, a hot-shoe and wireless off-camera flash capability.

Built-in Wi-Fi provides easy linking to smartphones or tablets. Images are stored on SD/SDHC/SDXC cards, including UHS-I-compliant. A new Tough Battery is CIPA-rated for 500 to 550 images per charge (depending on the lens), and the optional Battery Grip DMW-BGGH3 doubles that. Estimated Street Price: $1,299.

Samsung NX20

Samsung NX20. The NX20 features a 20.3-megapixel, APS-C Samsung CMOS image sensor, as do all current NX mirrorless cameras. But the NX20 also features a “mini-DSLR” design, while the other NX cameras (except the next Galaxy NX) use a “flat” compact camera-style design. There’s a built-in SVGA (1440K-dot) eye-level electronic viewfinder to complement the bright, tilting and rotating 3.0-inch, 614K-dot AMOLED monitor.

A top shutter speed of 1⁄8000 sec. with a very brief lag, along with 8 fps shooting at full resolution, puts the NX20 right in there with the top APS-C DSLRs in terms of shooting speed. It can shoot at up to 30 fps at reduced 5-megapixel resolution.

Video features include full HD 1920×1080, HD 1280×720, 640×480 and 320×240 at 30p, plus widescreen 1920×810 at 24p. There’s also Multi Motion that lets you produce clips at ¼ to 20X normal speed. Sound is stereo via a built-in microphone, and there’s a jack for an external mic.

In i-Function 2.0 mode, you can make many camera settings using the lens’ focusing ring. The depth-of-field preview button can be programmed for other functions, including activating/deactivating the RAW+JPEG feature.

Built-in Wi-Fi means you don’t need a Wi-Fi card or other device to upload your images to a social-networking site or compatible smartphone, or e-mail them. Estimated Street Price: $599 (with 18-55mm zoom).

Sony NEX-7

Sony NEX-7. It’s two years old now, but Sony’s NEX-7 is still the top model in the NEX mirrorless lineup. Its 24.3-megapixel Sony Exmor APS HD CMOS sensor offers the most megapixels (and highest sensor rating) of any mirrorless interchangeable-lens camera. ISOs run from 100-16,000. The built-in, eye-level, 2,359,000-dot XGA OLED Tru-Finder is the best EVF we’ve seen (it’s also used in Sony’s A99, A77 and A65 translucent-mirror DSLRs and the NEX-6 mirrorless model); it’s complemented by a 3.0-inch, 921,000-dot tilting LCD.

The NEX-7 can shoot 24.3-megapixel images at 10 fps (with focus and exposure locked at the first exposure), or 2.5 fps with continuous AF and exposure adjustments. Shutter release lag is a class best 0.02 seconds. AVCHD Progressive v2.0 format video can be shot in 1920×1080 full HD at 60p, as well as the usual 60i, and 1080/24p for a more “cinematic” look. There’s also 1440×1080 and 640×480 MP4 video at 30p when smaller files are desired. A built-in stereo microphone provides Dolby Digital stereo sound.

AF is contrast-based (the newer NEX-6 offers quicker hybrid phase-detection/contrast AF). The LA-EA2 adapter lets you use Sony A-mount (and legacy Konica Minolta Maxxum) lenses on the NEX-7 and provides a fixed translucent-mirror and phase-detection AF similar to that in the SLT-A65. The NEX-7 also provides manual focus peaking, which outlines in-focus edges in your choice of white, red or yellow, making it easy to see just where focus is in the image.

The first NEX to feature a built-in flash unit, the NEX-7 also has a hot-shoe for an external accessory flash and an adapter that provides a PC terminal for studio flash systems. Estimated Street Price: $1,099 (body only); $1,249 (with 18-55mm zoom).


A big part of a DSLR system is a wide range of accessories. Mirrorless cameras offer fewer accessories, but there are some good ones.

For its X-series cameras, Fujifilm offers three flash units, handgrips, a remote release and an adapter for Leica M-mount lenses, plus filters, a leather case and the XF lenses.

Olympus offers electronic viewfinders for the current models that don’t come with one (including a new tilting VF-4 with 2.36 million dots and 1.48X magnification), three flash units and a macro arm light (plus flash brackets and a hot-shoe flash cable), a remote cable release, Four Thirds and OM lens adapters, and fisheye, wide and macro converters.

Panasonic offers a battery grip for the GH3, and for all models, three flash units, a stereo shotgun microphone, adapters to use Four Thirds, Leica M and Leica R lenses, a remote shutter release, fisheye/wide/tele/macro adapters, and a zoom lever to help smooth zooming during video shooting.

Samsung mirrorless accessories include four flash units, an NX external microphone and a remote shutter release.

Accessories for Sony NEX mirrorless cameras include flash units, lens adapters (including one that adds phase-detection AF with Sony A-mount DSLR lenses), fisheye and ultrawide converters, a stereo microphone, a wireless remote commander unit, a five-inch external HDMI monitor (with headphone jack and LCD hood), and for the NEX-5T, a tilting, 2359K-dot OLED eye-level Tru-Finder.

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