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Sony a7 Review: Catapulting the Mirrorless Market
by Theano Nikitas -  12/31/2013

Sony rocked the photographic world when it launched the first full-frame mirrorless cameras, the a7 and a7R. These cameras catapulted the mirrorless market into the forefront of technology for many MILC advocates. But those outstanding specs don't mean anything if the cameras' features and performance don't live up to the hype. Read on to find out if these cameras met our expectations.

Overview

The idea of packing a compact camera with the same (or similar) features and image quality of a DSLR is, of course, highly appealing. And mirrorless interchangeable lens cameras have promised to meet those needs but, often, with a smaller sensor. But the a7/a7R have gone beyond current models by incorporating a full-frame sensor.

The two cameras are almost clones of each other and while this review focuses on the a7, we'll comment (where appropriate) on the a7R as well. To start, the biggest difference between the two is the sensor. The a7 uses a 24-megapixel full-frame sensor with hybrid autofocus, which utilizes on-chip phase and contrast detection AF. Perhaps the main difference between the two is that the a7R is built around a 36-megapixel full-frame sensor. Additionally, the a7R lacks an optical low pass filter (OLPF)--a trend that we're beginning to see in high end cameras to help ensure that the a7R delivers the ultimate resolution (hence the addition of the letter "R" to the name). Both have Wi-Fi, the must-have feature of 2013.

At the same time, Sony announced several FE lenses--e-mount lenses that cover the camera's full-frame sensor (otherwise you need to use the camera's crop mode or be okay with the vignette that non-FE lenses deliver). These FE lenses include the kit 28-70mm, f/3.5-5.6, the Zeiss 55mm, f/1.8 and the Zeiss 35mm, f/2.8. Next up is a 24-70mm, f/4 lens due soon. But Sony and third-party adapters, such as Metabones, are available to attach a wide range of lenses. Sony's FE lens roadmap promises a total of 15 lenses by 2015 but photographers are currently making good use of adapters to happily attach a wide range of Sony and third-party lenses to these two cameras.

I tested the cameras with the three FE lenses and spent a brief time with a prototype of the Zeiss Otus 55mm, f/1.4 lens as well. Read on to find out what I thought about the a7 and the lenses.

Build and Design
Although not quite as tank-like as the Sony RX1 (the a7 weighs a manageable 16.7 ounces), the a7 is well-made and feels solid in the hand. It's built around a magnesium alloy body and is dust and moisture resistant (yes, I shot with it in the rain with no ill effects). Relatively compact at 5 x 3.75 x 2 inches, the a7 is small enough--particularly when equipped with the FE 35mm lens--to meet my ideal size and weight for mirrorless interchangeable lens camera (ILC). The kit and FE 55mm lenses add more bulk and weight but are still relatively compact. And although longer lenses, like the large, heavy Zeiss OTUS 55mm sort of defeat the purpose of having a carry-anywhere mirrorless camera, the a7 and its feels well-balanced regardless of which lens is attached.

Ergonomics and Controls
Shooting with the camera is, for the most part, a pleasure. A contoured handgrip and a well-positioned thumbrest provide a solid and comfortable hold--good enough for one handed shooting with short lenses like the FE 35mm. While I appreciate the control layout, my hands are relatively small so it's a little bit of a stretch to reach a couple of the controls, such as the mode dial. But that didn't interfere with my ability to enjoy shooting with the a7.

Overall, though, all controls are easy to access and operate. The biggest issue is that there are so many custom options that one can be easily overwhelmed when setting up the camera and then equally baffled when trying to remember what features and functions were customized. But being able to choose from 46 functions to customize buttons and dials is a challenge I'll happily face any day.

The top deck of the camera is home to the mode dial, with the standard PASM options, auto and scene modes. Other modes include sweep panorama, two custom settings, intelligent auto and movie (movies can be started/stopped independently by pressing the red dedicated movie button on the side of the camera in most modes). To the right you'll find the shutter button/power switch, along with a separate exposure compensation dial (which I love), a custom button. Forward and rear dials are integrated in front of and to the rear of the camera's right top panel.

A tiltable LCD (which I'll discuss later) takes up the bulk of the rear real estate but still leaves plenty of room for other controls including a menu button to the left of the EVF. Placement there is a little awkward but once you set up the camera, you'll rarely need to access the menu anyhow. To the right of the EVF is another custom button, followed along the right edge of the LCD with the remaining external controls: AE/MF and AEL switch, a Fn button to call up a quick on-screen menu for most commonly used functions, a rotating control wheel that also functions as a 4-way controller to set display options, white balance, drive/self-timer. Below that sits the playback and delete buttons; the latter can be assigned a custom function for use in capture mode.

The red direct movie button on the side of the camera (to the right of the thumbrest) is a little awkward to use but not terribly inconvenient. And its position frees up more room for other, more frequently used controls.

A multi-interface/hotshoe is located in the center of the top deck atop the electronic viewfinder. The interface is no longer proprietary and will now accept ISO standard accessories, along with Sony accessories such as a hotshoe flash (there's no built-in flash), video light, external microphone and XLR adapter.

I have almost no complaints about the control layout, which is unusual for me. And, in the end, that really says a lot about the a7's design.

Menus and Modes
As much as I love the company's NEX cameras, the NEX user interface is frustrating to use. Fortunately, the a7's menu system is like that of the RX1. While you won't spend much time in the a7's menu system thanks to the external controls and custom options, when you do, you'll be pleasantly surprised. But, if you're a fan of the NEX icon-driven menu, there's an option to switch to a similar graphical interface.

The internal menu system is logical and features easy-to-navigate pages. Each page is self-contained so rather than scrolling down to get to the next page, a quick press of the 4-way controller quickly moves to the next page or tab. I'm sure other people prefer menus that wrap but I happen to like the a7's menus just the way they are.

Menu options include everything from image size and quality, noise reduction settings, the ability to save (or not save) individual settings and much more, as well as options for the camera's Wi-Fi and PlayMemories apps.

 

Multiple on-screen display options are available and are generally easy to navigate. Press the function button for an on-screen display of parameters of ISO, metering mode, flash compensation, white balance, DRO (dynamic range optimization) and more. Then use the control wheel/four way controller to change any of those settings.

There's also an on-screen menu that comes in handy when you're using the EVF. Just press the up arrow on the 4-way controller to change the screen display. This allows you to view your current settings on the LCD while focusing and composing with the EVF. If you want to change settings from this screen, just press the Fn button and use the 4-way controller to navigate to the functions you want to adjust.

Display and Viewfinder
One of the issues facing photographers using some mirrorless ILCs is that not all of them have a built-in EVF. Fortunately, the a7 comes equipped with a large and bright electronic viewfinder. This XGA OLED EVF provides a sharp, 100% field of view. Unfortunately, the dioptic adjustment falls just short of what I need to shoot without my reading glasses. Still, even with the glasses, it's comfortable to use.

The camera has an eye sensor that automatically switches the view between EVF and LCD, which can get annoying when trying to shoot from waist level using the LCD. The eye sensor is so sensitive that just holding the camera in front of your body puts it into EVF mode, so you're left with no way of composing an image. I found this happened most often when shooting in portrait mode and using the tilt LCD. There's no button to turn the EVF or the LCD off like other cameras that have a Live View button to activate/turn off the LCD. Instead, you have to go into the main menu system and change the monitor setting to Auto, monitor or EVF. It's not a dealbreaker but it would be so much more convenient to have a Live View button on the back of the camera.

The a7's 3-inch, 921,600-dot LCD also offers 100% field of view. It works well under most lighting conditions and offers a sunny weather mode to help visibility under bright skies, as well as a 5-step (+/- 2) manual brightness control. While it's not fully articulated, the LCD tilts enough to be useful for waist level (or lower) and overhead shooting. Numerous display options are available including a grid, level gauge, histogram and, as mentioned earlier, shooting information. The a7 offers focus peaking with a choice of levels and colors, as well as a magnified display for manual focus and in playback.

Performance

Neither the a7 nor the a7R are well-suited to fast action shooting, although the a7 can shoot continuously at about 5 fps, with the 36-megapixel a7R dropping to about 4fps. That said, I was able to easily capture a horse galloping at moderate speed so you can stop action but I wouldn't trust it when shooting sports or a Formula One race.

The cameras are both slow to start up, which was surprising and both seem to be power hogs. The a7, for example, is rated at about 340 shots per charge but that seems to be a little optimistic (even when the WiFi is not used). Fortunately, the a7's on-screen power indicator is pretty accurate and displays the percentage of battery life left so you shouldn't get caught short if you pay attention (and have a second battery). You can also charge the battery via USB, so if you have a newer car, you can even charge the camera while you're driving around. AC charging is, of course, available as well.

Autofocus worked pretty well on both cameras, although the a7's hybrid AF system was faster than the a7R. Since the phase detection coverage doesn't reach to the far edges of the frame, the a7's AF speed also depended on your composition. Both cameras' AF worked best in brighter light but I had some good experiences (and some not so great luck) with AF when shooting in low light. Outdoors, though, the tracking AF seemed to be fairly accurate for both models.

One complaint I have--and I know I'm not alone in this--is that both cameras are very noisy when you click the shutter. The a7 is a little quieter than the a7R but do a sound test before you buy one if you plan to use the camera in quiet environments like wedding ceremonies.

Lenses
As mentioned earlier, the a7 is equipped with an E-mount, like Sony's NEX cameras. However, because the a7 uses a full-frame sensor, E-mount lenses don't cover the full sensor and will cause vignetting unless you set the camera to shoot in crop mode.

Currently, there are only three FE lenses designed for the a7's full-frame sensor: the a7's kit 28-70mm, f/3.5-5.6, the Zeiss 55mm, f/1.8 and the Zeiss 35mm, f/2.8. An FE 24-70mm, f/4 lens is due soon and, by 2015, Sony plans to have 15 native FE lenses for the a7. Meanwhile, there are several options to attach A-mount and third party lenses to the a7. Sony offers two adapters for A-mount lenses, the $200 LA-EA3 and the $350 LA-EA4. The latter has phase detection AF built in, providing faster AF. Metabones offers a wide range of adapters for the a7 including those for Canon, Nikon, and Leica lenses, to name a few. (Note: Metabones Speed Booster automatically switches to crop mode on the a7/a7R.)

Of the handful of lenses I tried with the a7, I have to say that the FE Zeiss 35mm, f/2.8 is my favorite. I like wide angle lenses and this one delivered sharp, crisp images, with edge-to-edge sharpness. And, as I mentioned earlier, it's so small and light that the 35mm lens makes the a7 the size and weight that's perfect for carrying this camera anywhere.

That said, Zeiss OTUS 55mm, f/1.4 lens is one sweet lens. It's incredibly sharp and, when paired with the a7R, is astounding. On the other hand, it's large, heavy and manual focus only. Since I was shooting in very low light, with the aperture at f/1.4, I had a difficult time focusing, even with focus peaking since there was so little depth-of-field. But the areas that were in focus were incredibly crisp. Oh, before I forget there's one other detail you should know about the OTUS. It costs $4,000.

I also liked the FE Zeiss 55mm lens, although it was larger and heavier than I anticipated. But images were sharp and clear and it's a focal length that most of used when we first started shooting 35mm.

The a7 kit lens, at 28-70mm, provides a good zoom range for everyday shooting. It's not terribly fast at f/3.6-5.6 but I found that the a7's autofocus performed best in good light anyhow, so it matches well--especially if you shoot mostly in daylight or in the studio. I found that most, albeit not all, of my test shots were nicely focused.

I also tried a 70-200mm lens, although it was borrowed and the metadata doesn't show what brand it was (my guess is Sony). It was large, heavy and, again, difficult (for me) to focus manually, even with the camera's magnified view. But the a7/a7R felt pretty well balanced even with the long lens attached.

Wi-Fi and Apps
Wi-Fi is pretty much a mandatory feature on new cameras these days and the a7 doesn't disappoint. The a7 is also equipped with NFC (Near Field Communication) technology, which makes it easy to connect with compatible mobile devices--all you have to do is tap the camera and device together and you're set. Using the a7 with an iPhone (or an iPad) is easy, although not as simple as with NFC. Typing in my network password would have been so much easier if the a7 had a touchscreen but it only took a minute or so to use the virtual keyboard to enter the information and I was able to connect the a7 and my iPhone with little hassle so I could easily transfer images to my mobile device.

Sony also offers a series of apps from its Play Memories online store that can be loaded directly onto the camera. Cost ranges from free to about $10. At this stage, not all of the apps are currently compatible with the a7 but Sony promises that they will be in the future. However, you can use the Smart Remote Control app, for example, to control the camera from your phone/tablet, or use direct Upload to send images directly to social media accounts.

Video Quality
The a7 offers a full range of video options from 1920 x 1080 HD at 60p/60i or 24p in AVCHD as well as space saving MPEG 4 options.

Let's get the bad news out of the way first. I mentioned the position of the red video button before as being awkward but it's important to mention it again. When you push the red button from the side to active video recording and to stop recording, the camera is going to move from the pressure so you may have to edit out the first and last second of the clip. Also, while video quality is good--and certainly better than previous NEX cameras, for example--the a7 (and the a7R) exhibited moire. Surprisingly, though, there wasn't much difference that I could see in terms of quality between the two.

On the other hand, you have manual control over exposure and video quality is good, albeit not exceptional. But I was pleased, overall, with exposure accuracy, color rendition and smoothness of the footage. You'll need an external microphone for the best sound, of course, but the built in stereo microphones delivered better-than-expected audio.

Image Quality
Overall, despite a little moire, the a7R's image quality bests that of the a7 but that's no surprise given the camera's 36 megapixel sensor and lack of OLPF. Images from the a7R are mind-bogglingly good. However, the a7 is no slouch when it comes to image quality.

Test shots were, for the most part, impressive with sharp details, natural color rendition and generally accurate exposure. Although DCR editor and photographer Laura Hicks had a worse experience with the kit lens than I did, I was happy with most of my images, regardless of lens used. However, test shots with kit zoom lens were less likely to be consistently as good as those with other lenses, particularly the FE Zeiss 35mm. Laura was not terribly happy with the a7's processing on skin tones and textures while I thought that flaws in my people test shots might have been more the result of ISO and lighting. However, when looking more closely, I can see that the a7 sometimes lost a little skin and hair texture in some areas. But, I wouldn't hesitate to shoot portraits--or any other subject--with the a7 or the a7R.

Both cameras perform well in low light, although I tend to think that the a7 has a slight edge over the a7R in terms of image noise, especially given the a7R's higher resolution. On the other hand, the a7R tends to maintain detail a little better. In some senses, though, this is comparing apples and oranges due to the difference in resolution.

With the a7, I feel very comfortable shooting at ISO 1600. After that, details tend to get a little mushy and, depending on lighting conditions, grainy image noise is even more visible. On the other hand, shooting extremely dark scenes, the darkest shadows (blacks) are rich and deep.

I'm not thrilled with Sony's in-camera noise reduction and always turn it off. I'd rather take care of image noise or any other issues in post, so shooting RAW (or RAW + JPEG) is--in my opinion--the best way to go.

Sony a7 Sample Images


Sony a7R Sample Images


Conclusion

There's no doubt that Sony has raised the bar for all other camera manufacturers with the release of the a7/a7R. These cameras go far beyond the basic excitement of being full-frame mirrorless cameras. A broad feature set with extensive custom options will attract photographers who want to maintain control over their image taking while those who prefer a simpler workflow can go with the cameras' Program mode and leave the rest of the settings at default. 

Perhaps the bigger issue, for some, is choosing between the a7 and the a7R. Frankly, I'd happily pay the extra $300, put up with some more, slightly slower performance and huge files to get the extraordinary resolution of the a7R over the a7. On the other hand, not everyone wants or needs a 36 megapixel camera, which will quickly fill up hard drives.

While the performance of both cameras--including slow start up, slightly sluggish AF in low light and slow continuous shooting vis-a-vis DSLRs--leaves something to be desired, the image quality is outstanding. And, in the end, that's what really counts.

Pros

Cons