Sony Alpha 7 review

The Sony Alpha 7 is a fast-shooting, full-frame mirrorless camera that's capable of capturing some impressive images, but overall, we prefer its sibling, the 7R.
Photo of Sony Alpha 7

The Alpha 7 ($1,699.99 direct, body only) is one of a pair of new full-frame mirrorless cameras from Sony. Aside from the model badge, it looks the same as its twin, the Alpha 7R, but the two cameras are quite different internally. The Alpha 7 is built for speed thanks to a 24-megapixel image sensor with on-chip phase detect autofocus sensors and a 5fps burst shooting rate. The camera is impressive and a joy to use, but we give the edge to the 36-megapixel Alpha 7R, which earns our Editors’ Choice award for full-frame mirrorless cameras. For an extra $600 you sacrifice just a little bit of speed, but gain a 50 percent increase in image resolution and a images that are critically sharp thanks to a sensor design that omits the low pass filter.

Build
Quite compact when you consider its full-frame image sensor, the Alpha 7 measures just 3.75 by 5 by 1.9 inches (HWD) and weighs about a pound without a lens. The Leica M (Typ 240), the first full-frame mirrorless camera with Live View, measures 3.1 by 5.5 by 1.7 inches, but is heavier at 1.5 pounds. The Leica gets some of its extra weight from its brass construction and optical viewfinder; the Alpha 7′s extra height is due to its built-in OLED EVF. The body itself is sealed against dust and moisture; I had no issues shooting in lighter rain. Lenses don’t have an o-ring gasket around the mount, so I’d be a little wary of using the camera in very heavy rain.

The Alpha 7 uses the same E-mount to attach lenses as previous Sony NEX cameras, including the NEX-6, which uses an APS-C image sensor. An APS-C sensor is physically smaller than the 35mm full-frame image sensor housed in the Alpha 7′s svelte body. It’s possible to use older lenses for NEX cameras that only cover an APS-C image circle; the Alpha 7 will automatically crop images to match the APS-C sensor size when these lenses are attached. Lenses designed for the full-frame Alpha 7 and 7R bear an FE designation.

The Alpha 7′s 24-mexapixel image sensor is the same physical size as the one found in the Alpha 7R (and Leica M), but it has something that those cameras lack: an optical low pass filter (OLPF). The OLPF is designed to reduce the possibility of color moiré effects in images. These can show up as rainbow patterns when shooting certain textures, notably textiles and feathers. It does this by slightly blurring an image, at the cost of very fine detail. It’s easier to reduce moiré via software when working with high resolution images, which is one of the reasons that they’ve long been omitted from medium format digital cameras. As image sensors have increased in resolution, and modern lens designs in sharpness, more full-frame 35mm and APS-C digital cameras have omitted the filter, the logic being that it’s better to address moiré when it does pop up in an image rather than to sap detail from every photo. Whether or not you want a camera with this filter is a matter of personal preference and the subject matter which you deal with. Landscape photographers rarely see it, and don’t need the fast burst shooting capability that the Alpha 7 delivers, which will likely push them to the 7R. If you regularly photograph fabrics, birds, or other moiré-inducing objects, you’ll want a camera with an OLPF. 

Physical Controls, Display, Wi-Fi
The A7 puts shooting controls at your fingertips via a well-designed selection of physical controls. There are front and rear control wheels, placed at the top of the camera and accessible when holding it using the handgrip. The top plate houses a standard mode dial, the power switch and shutter release, an EV compensation dial (3 stops in either direction at 1/3-stop increments), and the customizable C1 button—by default it adjusts autofocus pattern, but when the camera is in manual focus mode it enables quick frame magnification as a focus aid.

On the rear of the camera you’ll find the Menu button to the left of the eyepiece, and the C2 button to its right; C2 is also customizable, and is used to adjust the focus mode by default. The other controls are bunched to the right of the tilting rear LCD; there’s a toggle switch and button that give quick access to manual focus mode when placed in the up position, and engages exposure lock in the bottom.

A flat control dial can be spun to adjust the ISO, or pressed in a cardinal direction to adjust the drive mode, change the amount of information displayed over the Live View feed, or to adjust white balance. At its center is a button that is used to select items in menus; when shooting it enables Eye AF, which prioritizes the autofocus system to lock onto a human eye. The delete button doubles as C3 when shooting; there’s no default behavior, but you can add one via the menu. All of the rear controls are customizable, giving you near total control over how the camera functions. If a certain control is seldom used, or just isn’t the right place, you can adjust it to suit your needs.

The other control button on the rear is the Fn button. It brings up an on-screen menu that provides quick access to up to 12 camera functions. The default lineup includes the drive mode, flash mode and compensation, the focus mode and area, exposure compensation, ISO, the metering pattern, white balance and color output settings, dynamic range optimization settings.

There’s a record button to start videos, its located on the right side of the camera; it’s actually placed quite well, and is easily accessibly but unlikely to be accidentally pressed; it can’t be disabled or reprogrammed, but it can be set only to work when the camera’s mode dial is moved to the video setting.

The LCD is hinged so it can tilt up or down, but it’s not a vari-angle display like the one found on the Panasonic Lumix DMC-GH3, nor does it support touch input. It’s 3 inches in size and packs 921k-dot resolution into that space, which is impressively sharp. There’s no depth of field preview button on the camera, instead the Live View feed changes to show you the focus, depth of field, and exposure as you adjust the aperture of the lens.

Wi-Fi, Interface, and Apps
The EVF is an OLED panel with a 2,359k-dot resolution, similar to the one found in the NEX-7 and other APS-C Sony mirrorless cameras. It’s one of the best you’ll find in a digital camera, although we give slight preference to the LCD EVF in the Olympus OM-D E-M1. The LCD tends to give a more natural impression of a scene, while the OLED tends to produce a punchier view of the world with a bit more contrast. The EVF can lag a bit in very low light; it’s not quite as smooth as the E-M1 in those conditions, but it is smoother than the EVFs in Sony cameras from previous years.

The Alpha 7 features built-in Wi-Fi. By default it’s a pretty simple implementation—it allows for transfer of images to your iOS or Android device via the free Sony PlayMemories Mobile app, available from Apple and Google Play. The camera broadcasts an SSID to which your phone connects so you can transfer images when out and about; NFC pairing is available if your device supports it. Even if you’re a Raw shooter you’ll be able to take advantage of this function, as the Alpha 7 can extracted the embedded JPG image from the Raw and send it over. If you’re shooting video you’ll have to use the MP4 format for transfer; AVCHD footage still needs to be loaded onto a computer via cable or memory card. You can also transfer images or video to a PC, or view them wirelessly on a compatible HDTV.

The menu system is a departure from previous NEX cameras. It’s largely text based, with pages and pages of options. Thankfully you won’t have to spend too much time in it once you’ve got the camera configured to your liking, and it’s not a bad thing that Sony has given photographers control over how much of the camera the menu system operates. It’s broken up into six sections: Camera Settings, Custom Settings, Wireless, Application, Playback, and Setup. Navigating through them is as simple as scrolling left and right to change pages and up and down to access particular settings. If you are a fan of the old tile based NEX menu you can enable it, although all that does is present a splash screen with large icons for each of those six submenus; once you get past that the menu interface is unchanged.

Sony’s PlayMemories app store was introduced along with the NEX-6, and it offers a number of programs that can be downloaded to expanded the functionality of the camera. Sony has built out the app library for APS-C NEX cameras, but there are only a pair of apps for the Alpha 7 and 7R available at this time. There’s the Smart Remote Control, which allows you to control the camera from your phone or tablet. It’s a pretty robust remote; you can tap an area of the Live View feed to focus, and fire the shutter. But you also have access to full shooting controls depending on what mode the camera is in. They vary a bit by shooting mode, but you can adjust the shutter speed, aperture, exposure compensation, ISO, and white balance, and set the self-timer—all from your phone or tablet.

The other app is Direct Upload. If you’re near Wi-Fi with Internet connectivity, or using your phone as a hotspot, this app lets you push images to Facebook or to Sony’s PlayMemories online service. There’s a sidecar app that adds support for Flickr. It’s a simple, straightforward process that makes it easy to share images with friends and family.

Non-Native Lenses
The short distance between the image sensor and lens mount makes it possible to practically any lens designed for a 35mm camera to the Alpha 7 via an adapter. Sony SLR shooters can add the LA-EA3 or LA-EA4 adapter and enjoy full autofocus compatibility with A-mount lenses from Sony and Minolta. The Alpha 7 can also accept Canon EOS lenses via an adapter by Metabones, and there are mechanical adapters out there for Nikon F, Pentax K, Leica R, and lenses from many other SLR systems. Most adapted lenses will be manual focus only, even if the lens supports autofocus. At this time the Sony/Minolta A-mount and Canon EOS lenses are the exception, and there is an autofocus adapter in development for Contax G rangefinder lenses.

But a lot of folks are going to look at the Alpha 7 as a platform for Leica M rangefinder lenses, especially considering that it’s priced about $3,700 less than the least expensive full-frame digital Leica, the M-E (Typ 220). These lenses are manual focus only, so a simple mechanical adapter is all that’s required to mount them.  They are generally compact, and if modern lenses like the Leica Summilux-M 50mm f/1.4 ASPH., are phenomenal from an optical standpoint. Rangefinder lenses are typically fairly limited in close focus, but with the Hawk Peng Macro Helicoid Adapter, which acts as a variable extension tube, the limitation is lessened. The Leica Elmarit-M 28mm f/2.8 ASPH. is able to focus as close as 0.2 meters with the adapter, versus 0.7 meter without it.

The Alpha 7′s 24-megapixel image sensor generally does a good job with adapted lenses. Sony states that offset microlenses have been incorporated into both the 7 and 7R to improve corner performance, but they are optimized for native lenses. These lenses straighten light that comes in at steeper angles at the edges of the frame so that the image sensor can properly collect it. The Alpha 7 generally produces good results when paired with rangefinder lenses, even a wide-angle optic like the Elmarit-M 28mm f/2.8 ASPH. When used with the Alpha 7R this lens shows a moderate amount of purple color shift at the corners of the frame; the microlenses on that sensor, combined with its higher pixel depth, can’t fully compensate.

The Leica M (Typ 240) uses a similar microlens system to improve corner performance when paired with M-mount lenses. Not surprisingly, the Elmarit 28mm is a better performer on it than it is on either the Alpha 7 or the 7R, especially at the corners. Imatest shows that the lens manages about 1,347 lines per picture height at the out edges of the frame on the M (Typ 240); it only musters 489 lines at the edges of the frame on the Alpha 7. It fares a little worse on the 7R, and shows the color shift on top of that.

And then there’s an ultra-wide angle lens like the Voigtlander Super-Wide Heliar 15mm f/4.5 Aspherical. I only had the older Leica Thread Mount version of the lens on hand for testing, not the more recent M-mount version. The edges and corners of the frame are just as blurry with the Alpha 7 as the Elmarit-M 28mm ASPH., but the Alpha 7 does manage to avoid showing color shift with that lens. It’s one that shows moderate color shift on the Leica M, although the corners are sharper at f/4.5 there than they are with the Alpha 7, and extreme purple color shift on the 7R.

What the Elmarit-M 28mm ASPH. and the Voigtlander Super-Wide Heliar 15mm have in common is a symmetrical design. Wide-angle SLR lenses, like the Pentax SMC FA 31mm f/1.8 Limited typically employ retrofocus designs—in very basic terms a reverse telephoto—and perform much better on the A7 and A7R. But even that lens showed some edge softness on the Alpha 7 when compared with the Leica M. At f/1.8 the edges showed 1,425 lines on the Alpha 7, 1,281 lines on the 7R, and 1,560 lines on the M. Edges improve as you stop down, regardless of the camera body used, and by f/4 it’s an impressive performer on all three cameras, but the Leica still wins in terms of edge-to-edge sharpness.

The Leica M enjoys one more advantage over the Alpha 7, but whether it’s worth the premium price is up to you. When shooting with rangefinder lenses, the optical viewfinder and bright patch deliver a quicker manual focus experience than the Alpha 7′s OLED EVF is able to. I’m able to get sharp, in-focus shots with a 50mm f/1.4 and the Leica M rather quickly, but to do the same on the Alpha 7 I really had to use the magnification function. By default that’s C1 on the top plate when using a manual focus lens, and it brings up a 7x view of the frame in the eyepiece or on the rear LCD. Focus peaking, which highlights in-focus areas of the frame, is available for working more quickly, but I found that I had to stop a 50mm lens down to about f/4 before the peaking did the job on its own. When working slowly the magnification is extremely precise, but for quick shots I still prefer an optical rangefinder. Granted, there are caveats to that—a rangefinder lens and camera need to be properly calibrated to really nail focus; if your M lens and camera aren’t quite matched properly you’ll never get an in-focus shot, but that’s been the nature of rangefinder cameras since their inception.

Native lenses are much better performers. The Sony Carl Zeiss Sonnar T*FE 35mm F2.8 ZA and Sony Carl Zeiss Sonnar T* FE 55mm F1.8 ZA are impressively sharp from edge to edge on both the Alpha 7 and 7R.

Performance and Image Quality
The Alpha 7 is the speedier of the two inaugural full-frame Sony mirrorless cameras. It starts and grabs an in-focus photo in about 1.7 seconds, focuses and fires in about 0.05-second in good light, and requires about 0.7 second to do the same in very dim light. It captures images at 5 frames per second when set to its Speed Priority mode. It can manage that pace for 24 Raw+JPG, 27 Raw, or 55 JPG shots before slowing down. The time to fully clear the buffer to a SanDisk 95MBps memory card varies based on format; 20.3 seconds for Raw+JPG, 14.7 seconds for Raw, and 29.6 seconds for JPG.

The only other autofocusing full-frame mirrorless camera on the market is the Alpha 7R. The two cameras use different autofocus systems; the Alpha 7 has phase detect pixels on its sensor, although they are grouped around a center area, indicated on the Live View screen. When the camera needs to focus outside that area it falls back to contrast detection, the same focus method that drives the A7R. There are plenty of focus areas from which to choose, including Center and Zone areas that restrict the focus to the phase detect area, a Wide area that covers most of the frame, and three sizes of Flexible Spot focus that put you in control of the focus point.

The 7R starts and shoots in about 1.9 seconds, requires 0.2-second to focus and fire in ample light, and 0.9-second in very dim light. It’s just a beat slower than the Alpha 7 at every turn, including burst shooting where it manages 4 frames per second. It can keep that pace for 14 Raw+JPG, 15 Raw, or 15 JPG shots; it requires 18.7, 13.4, and 16.5 seconds to clear the buffer to the same SanDisk memory card as the Alpha 7, respectively. It’s no surprise that the 7R’s buffer can’t match up to the Alpha 7; the larger 36-megapixel images are the culprit there. The 7R packs more pixels, but it’s also a louder camera when shooting. The Alpha 7 supports an electronic first curtain shutter, so it only produces a single click when firing a photo, versus the louder clunk-clunk that opening and closing the Alpha 7R’s shutter requires.

We’re reviewing the Alpha 7 as a body only, but it’s also available in a kit with the Sony FE 28-70mm F3.5-5.6 OSS zoom lens for $1,999.99. That lens sells for $500 on its own, so that’s a $200 savings, but testing shows that it’s got some optical issues. There’s very noticeable distortion at both the wide-angle and telephoto extremes if you shoot in Raw mode (it’s automatically corrected when shooting JPG), and the edges are just not that sharp at apertures wider than f/8. If you don’t mind the compromises that come with an inexpensive zoom lens it’s a decent starter lens, but you’ll get much more out of the camera by pairing it with either of the two Zeiss ZE prime lenses that are currently available. A Zeiss zoom, covering a 24-70mm range at a constant f/4 aperture, is scheduled to go on sale in February for about $1,200.

We used Imatest to check images for noise here in the PCMag Labs. Our standard test showed that the Alpha 7 kept noise below the 1.5 percent threshold through its top ISO setting of 25600 when shooting JPG with default settings. Those settings apply some in-camera noise reduction, and image detail does suffer at ISO 25600 when shooting in JPG. I took a close look at images from our ISO test scene on a calibrated NEC MultiSync PA271W to take a look at how images held up at each ISO setting. JPG detail is better at ISO 12800, even with noise reduction enabled, but ISO 6400 is the top setting at which I’d shoot at default noise reduction settings with the Alpha 7. The Alpha 7R uses the same type of noise reduction, and also captures out-of-camera JPGs with acceptable noise through ISO 25600, but at that top setting its 36-megapixel photos actually hold up a bit better in terms of detail than the A7′s 24-megapixel photos.

You’ll get more detail, and a little more noise, if you set High ISO Noise Reduction to Low, or better yet, Off, in the camera menu. And if you’re willing to put the work in and shoot the Alpha 7 in Raw you’ll be happily surprised at just how much detail you’ll get at ISO 25600. Some quick work in Lightroom will net images with little noise and excellent detail through the top ISO, provided you start with a Raw image, just adjust the Luminance Smoothing slider to around 30. The rule of thumb that, given the same sensor size, a lower resolution camera will hold up better at higher ISO settings doesn’t apply to the Alpha 7 and 7R. Even though the 7R has a 36-megapixel image sensor, Raw images at ISO 25600 from the 7R show just a little bit more noise than those from the Alpha 7, and the extra resolution gives you more room to work with noise reduction without sacrificing detail.

Video Quality and Conclusions
Video is recorded in AVCHD format at up to 1080p60 quality; 1080i60 and 1080p24 are also available in that format, as are 1080p30 and VGA quality in the more easily shareable MP4 format. The AVCHD footage looks great; sharp details are preserved, colors are accurate, and the full-frame sensor provides excellent control over depth of field. The autofocus is just as quick as when shooting stills, there’s a mic input, a headphone output, and audio level control built into the camera. There is some evidence of the rolling shutter effect, which cause the bottom of the frame to advance more quickly than the top of the frame for a jello-like effect, during very fast pans, but it’s largely minimized during slow pans at 60p. That’s impressive for such a larger image sensor. Voices come through clearly on the audio track, and the sound of the lens focusing is silent, but if you make adjustments to camera settings when recording they’ll be audible. If you’re planning on using the Alpha 7 for any sort of serious video work, an external mic is a necessity.

There are a few ports on the camera. There’s a hot shoe on top of the EVF; it’s got extra data connectors that make it compatible with a number of Sony accessories. There’s no PC sync socket, but you can add a simple adapter to the hot shoe if you need to use the camera with studio lights, or trigger them using a PocketWizard PlusX. And there are standard mic and headphone jacks on the left side of the camera, along with a micro USB port and a micro HDMI port. The micro USB port doubles as a charging port—if you don’t invest in an external charger you’ll need to charge the battery in camera. It’s a Sony camera, so Memory Stick PRO Duo media is supported in addition to standard SD, SDHC, and SDXC media.

The Alpha 7 is rated for 340 photos per charge using the EVF, and you’ll get less if you utilize the LCD and Wi-Fi extensively. A second battery is a must for this camera, and Sony should have included a charger so that you could recharge that battery while shooting with the other. As such the charger costs $50 and a second battery is priced at $80 (but available for about half that if you shop around). If you prefer a beefier camera, a vertical shooting grip is available for $300; it can hold two batteries, effectively doubling the operating life of the Alpha 7. This is the one area where the Leica M actually looks like a better value than the Alpha 7 or 7R; it ships with a huge battery that’s rated for 800 shots using its optical finder, and it includes an external charger. But a second battery for the Leica is more than double the price the Sony, so that gap is quickly bridged if you opt to purchase a spare.

There’s a lot to like about the Sony Alpha 7. At this time it’s the least expensive full-frame camera on the market and its impressive autofocus system and burst shooting capabilities allow it to go toe-to-toe with many traditional D-SLRs. The short distance between the lens mount and sensor make it possible to use practically any lens for a 35mm system with the camera, including those with no native digital full-frame options available like Pentax K and Canon FD lenses. And, most importantly, the compact design is a pleasure to use. It’s not perfect—the two FE Zeiss primes are excellent, but the native lens library is its infancy so you’ll have to use adapted Sony Alpha SLR lenses for any telephoto or macro work that requires autofocus for the time being, the standard 28-70mm zoom that is available as kit lens is a little underwhelming, and if you’re an old rangefinder shooter looking for a poor man’s Leica, there are some issues with corner and edge sharpness when using wide-angle M-mount lenses—but not to the extent that the 7R displays with wide-angle rangefinder lenses.

But the camera’s strengths greatly outweigh its weak points. Sony promises to add about a dozen native lenses over the next few years, including a stabilized 70-200mm zoom by the middle of 2014. The video quality is excellent, as are the OLED EVF and the control layout. As much as we like the Alpha 7, we’re awarding our Editors’ Choice to the higher resolution Alpha 7R. Its higher resolution sensor and OLPF-free design deliver superior images when paired with the excellent FE Zeiss lenses, and its Raw image quality is impressive through its top ISO. It can’t match the Alpha 7 in burst shooting, but it can grab a decent number of shots at 4fps and its autofocus is adequate to capture most subjects. Action shooters may take exception to this verdict. If you frequently shoot sports or other fast moving action, the Alpha 7 will focus just a little bit faster and fire off shots at a 5fps pace. For the rest of us, the 7R is the better camera, and worth the extra $600 that it commands.

Specifications
Dimensions 3.75 x 5 x 1.9 inches
Interface Ports micro USB, micro HDMI, Mic, Headphone
Megapixels 24 MP
Recycle time 0.2 seconds
LCD dots 921600
LCD size 3 inches
Touch Screen No
Media Format Secure Digital, Secure Digital High Capacity, Memory Stick Pro Duo, Secure Digital Extended Capacity
Maximum ISO 25600
Type Compact Interchangeable Lens
GPS No
Boot time 1.7 seconds
Sensor Type CMOS
Weight 1 lb
Waterproof Depth (Mfr. Rated) 0 feet
Video Resolution 1080i, 1080p
LCD Aspect Ratio 4
Lens Mount Sony E
Shutter Lag 0.05 seconds
Sensor Size Full-Frame (24 x 36mm) mm
EVF Resolution 2359296 dpi
Viewfinder Type EVF

Verdict
The Sony Alpha 7 is a fast-shooting, full-frame mirrorless camera that is capable of capturing some impressive images, but we prefer its sibling, the 7R, overall.
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Copyright © 2012 Ziff Davis, Inc