Sony Alpha SLT-A55 Review

Look and Feel

If you didn't know anything about the Alpha SLT-A55, you'd take a look at it and assume it was just another D-SLR. However, as I mentioned earlier, it's anything but, with its translucent mirror and electronic viewfinder. The A55 has an average-size body by D-SLR standards, and it's made almost entirely of high grade plastic. The camera's grip is on the smaller size, but it's not too small like on some of its competitors. The controls are fairly well laid out, though the dedicated movie recording button is a bit of a stretch from where your thumb normally rests.

The translucent mirror design of the SLT-A55 allows for a much smaller footprint than traditional D-SLRs, like the Sony Alpha DSLR-A550
Image courtesy of Sony Electronics

Above is a size comparison between the SLT-A55 and Sony's DSLR-A550, which is a traditional D-SLR. As you can see, the new design of the SLT models has allowed for a pretty substantial reduction in size! Now let's take a look at how the the A55 compares to the various D-SLR and ILC cameras out there:

Camera Dimensions (W x H x D, excluding protrusions) Volume (bulk) Mass (empty)
Canon EOS Rebel T2i 5.1 x 3.8 x 3.0 in. 58.1 cu in. 475 g
Nikon D5000 5.0 x 4.1 x 3.1 in. 63.6 cu in. 560 g
Olympus E-620 5.1 x 3.7 x 2.4 in. 45.3 cu in. 475 g
Panasonic Lumix DMC-G2 4.9 x 3.3 x 2.9 in. 46.9 cu in. 371 g
Pentax K-r 4.9 x 3.8 x 2.7 in. 50.3 cu in. 544 g
Samsung NX10 4.2 x 3.4 x 1.6 in. 22.8 cu in. 349 g
Sony Alpha DSLR-A550 5.5 x 4.1 x 3.4 in. 76.7 cu in. 599 g
Sony Alpha SLT-55 4.9 x 3.6 x 3.3 in. 58.2 cu in. 433 g

The SLT-A55 may be a lot smaller and lighter than the DSLR-A550, but it's easily eclipsed by the mirrorless cameras from Panasonic and Samsung, as well as a few traditional D-SLRs.

But enough about that -- let's start our tour of the SLT-A55 now!

Front of the Sony Alpha SLT-A55

Here's the front of the SLT-A55, without a lens attached. The camera uses the same Alpha mount as Sony's other D-SLRs, and it'll work with classic Minolta lenses, as well. Whichever lens you end up using, you'll have a 1.5X crop factor to keep in the back of your mind. To release an attached lens, simply press the button located to the right of the mount.

Image courtesy of Sony Electronics

Before we continue the tour, I want to quickly give you a closer look at the A55's transparent mirror. You're actually seeing the the camera's 16 Megapixel Exmor R CMOS sensor there -- right through the mirror glass. The light that is reflected is sent upward to the camera's 15-point autofocus sensor.

Despite the fact that the mirror doesn't flip up and out of the way when a photo is taken, dust is still a concern. Thus, Sony uses both a anti-static coating on the low-pass filter, as well as a dust "shake-off" when the camera is powered off. You can also manually clean dust off of the sensor by pressing that tab below the mirror, which lifts the whole thing out of your way.

Another feature of the A55 (and all Sony D-SLRs) is sensor-shift image stabilization. The camera detects the tiny movements of your hands that can blur your photos, especially in low light, or when using a telephoto lens. The A55 is able to shift the CMOS sensor itself to compensate for this movement, allowing you to use shutter speeds that are 2.5 - 4 stops slower than you normally could. Image stabilization won't freeze a moving subject, nor will it allow for multi-second handheld exposure (though Sony has some tricks up their sleeves for that), but it's way better than nothing at all. And, since the IS system is built into the camera, nearly every lens you attach will have shake reduction. Want to see the A55's image stabilization feature in action? Have a look at these:

Image stabilization off

Image stabilization on

Both of the above photos were taken at a shutter speed of 1/2 of a second -- definitely tripod or flash territory. Nevertheless, I was able to get a sharp photo out of the SLT-A55, thanks to its SteadyShot system. You can also use this system to help smooth out your video recordings, as you can see in this brief video clip. Do note that using the image stabilizer in movie mode will dramatically reduce the maximum recording time, presumably due to heat issues.

Getting back to the tour now, the next thing to see is the SLT-A55's flash, which is released manually. The flash is relatively weak by D-SLR standards, with a guide number of 10 meters at ISO 100 (most cameras in this class have a GN of at least 12). If you want more flash power, you can attach an external flash to the hot shoe on the top of the camera, or cut the cord entirely and go wireless, which the A55 supports right out of the box. The flash is also used as an AF-assist lamp, helping the camera lock focus in low light situations. If you want to use it for focusing but don't want to take a flash photo, you can simply close the flash after focus is locked.

To the lower-left of the lens mount is the camera's depth-of-field preview button. Over on the grip you'll find the self-timer lamp as well as the receiver for the optional wireless remote control. Above that is the camera's sole control dial -- I wish it had another.

Back angled view of the Sony Alpha SLT-A55
Image courtesy of Sony Electronics

On the back of the SLT-A55 is a flip-down, rotating LCD 3-inch display. The screen can flip down 180 degrees, and then rotate 270 degrees, allowing you to take ground level or over-the-head photos with ease. The screen can also be put in a more traditional position (shown below) or closed entirely. While a rotating LCD is always nicer than a fixed one, I personally prefer screens that flip out to the side.

Back of the Sony Alpha SLT-A55
Image courtesy of Sony Electronics

Here's the LCD in a more traditional position. The screen has 921,600 pixels, so everything is super sharp. The display uses a technology that Sony calls TruBlack, which improves contrast and reduces reflections and glare. The TruBlack system delivers on its promises, offering excellent outdoor visibility, with the auto brightness adjustment feature helping considerably. In low light, the screen "gains up" quite a bit, so you still see your subject, though the view may be a bit grainy. I should point out that since this is a widescreen LCD, the image you're composing does not fill the screen (there will be a black margin on the sides), unless you're using a 16:9 aspect ratio. The wide LCD is great for recording movies, though all that space feels wasted when you're taking stills. The LCD also seemed to be a magnet for fingerprints, for some reason.

The "view" in live view

The translucent mirror design of the SLT-A55 means that you'll be using live view for composing all of your photos. Thankfully, Sony did an excellent job implementing this feature. You'll find a super-fast 15-point autofocus system, a live histogram, grid lines, face and smile detection, and frame enlargement for manual focus. The camera also shows a "shake meter" on the LCD/EVF, which helps you reduce the risk of blurry photos.

Electronic level in action

Another handy feature is an electronic level, which works for both tilt and pitch. When everything turns green, you're level! This feature is great for people like me who can't get a level horizon to save their life.

Just above the LCD is the A55's electronic viewfinder, which Sony calls a TruFinder. The TruFinder shows the same things as the main LCD, including menus. This large electronic viewfinder is 0.46" in size, with a magnification of 1.1X and 100% frame coverage. It packs a whopping 1.44 million total dots (480,000 pixels), so it's very sharp. Being a sequential field display, you may notice a "rainbow effect" when you blink or rapidly pan the camera. The TruFinder also seemed a bit washed out to me, which may make outdoor viewing a bit difficult. The A55 will automatically switch over to the TruFinder when you put your eye up to it, courtesy of a sensor just below it. This same sensor is used for the EyeStart AF feature, which activates the camera's autofocus system when you place your eye against the viewfinder. You can focus the image on the screen by using the diopter correction knob on its right side.

Now let's talk about buttons, starting with the four that surround the TruFinder. From left-to-right, we've got the Menu, movie recording, exposure compensation, and AE-Lock buttons. Those last two items can also be used for zooming in and out of an image (or display thumbnails) while in playback mode.

Function menu

Just to the right of the LCD is the Function button, which opens up a shortcut menu (whose icons are found on the black borders on the sides of the LCD). The items in the function menu include:

  • Scene Selection (Portrait, sports/action, macro, landscape, sunset, night view, handheld twilight, night portrait)
  • Sweep Shooting (Sweep Panorama, 3D Sweep Panorama) - choose whether you're taking 3D or regular panoramas
  • Drive mode (Single-shot, continuous lo/hi, 2 or 10 sec self-timer, 0.3/0.7 EV bracketing, lo/hi WB bracketing, remote commander)
  • Flash mode (Off, auto, fill flash, slow sync, rear sync, wireless) - the last option requires a compatible Sony external flash
  • Autofocus mode (Single-shot, automatic, continuous) - single AF locks the focus when the shutter release is halfway-pressed; continuous AF keeps focusing; automatic selects between the two based on the scene
  • AF area (Wide, spot, local) - first is 15-point auto, second is center-point, third is manual focus point selection
  • Face detection (on/off)
  • Smile Shutter (on/off)
  • ISO sensitivity (Multi-frame NR, Auto, 100, 200, 400, 800, 1600, 3200, 6400, 12800)
  • Metering mode (Multi-segment, center-weighted, spot)
  • Flash compensation (-2EV to +2EV in 1/3EV increments)
  • White balance (Auto, daylight, shade, cloudy, incandescent, fluorescent, flash, color temp, color filter, custom)
  • DRO / Auto HDR (DRO Off, DRO Level 1-5, HDR Auto/Manual)
  • Creative Style (Standard, vivid, portrait, landscape, sunset, black & white)

The very attractive scene selection menu

There's a lot to talk about before we can continue the tour. While the SLT-A55 is perfectly content to automatically pick a scene mode for you in its two auto modes, you can also select one manually in Scene mode. The only notable option in the Function menu is handheld twilight, which combines a series of six exposures into a single image, to reduce blur in low light situations. Here are two examples of the handheld twilight feature:

The handheld twilight mode cranked the ISO all the way to 6400 for the two photos you see above. While you probably won't be making 20 x 30 inch prints of either, these photos (handheld with the Sony 70-400 lens) are blur-free and are good enough for small prints or sharing online. Note all the orange in the top photo -- congrats Giants!

A sweep panorama (wide resolution) taken from atop Haleakala on Maui

The Sweep Panorama feature, a Sony original, is one of my favorite features on the A55. Point the camera at your starting point, and then "sweep" it in the direction of the arrow on the screen, and the camera will instantly stitch together a beautiful panorama (see above). You can select from regular or "wide" sizes, with the latter having a whopping resolution of 12416 x 1856 when panning horizontally. The A55 can also record 3D panoramas, and it does so by taking photos for the left and right eye as you pan across the scene, and saves everything into an MPO file. Naturally, you'll need one of those pricey new 3D televisions in order to view these. The examples I've seen were quite impressive.

In the drive submenu you'll find some of the A55's continuous shooting options. Here you can shoot at low (3 fps) or high speed (6 fps) -- and the A55 is capable of going even faster. But more on that later. Other options here include bracketing for exposure (in 0.3 or 0.7 EV increments) and white balance (in 10 or 20 mired increments). For both of those options, the camera takes three photos in a row, each with a different exposure or white balance value.

The SLT-A55 locked onto all six faces

The SLT-A55 shares the same face and smile detection features as Sony's compact cameras. The face detection feature can find up to eight faces in the frame, making sure they're properly focused and exposed. Sony has done a great job implementing this feature -- the A55 locked onto all six faces in our test scene with ease. The Smile Shutter feature goes on step further -- once it's turned on, it will wait until one of the people in the frame smiles, and then it'll start taking photos until you tell it to stop. You can adjust the sensitivity of this feature, from slight to normal to big smiles.

The ISO sensitivity menu is fairly self-explanatory, but I do want to tell you about the multi-frame noise reduction feature. In this mode, the camera will quickly capture a number of exposures, and then do some magic to combine them into a single photo with less noise than you'd normally get. You can set it to Auto (which I believe tops out at ISO 1600), or manually crank things all the way up to ISO 25,600. Does it actually work? See for yourself:

ISO 6400, standard JPEG

ISO 6400 via Multi-frame NR

ISO 6400 via RAW->JPEG conversion + NeatImage + Unsharp Mask

All three of the above photos were taken at ISO 6400. The first was just a regular shot, the second used the multi-frame NR feature, and the third is a RAW-> JPEG conversion. The multi-frame NR feature does reduce the noise level in the image, though it's pretty soft. The RAW conversion has more visible noise, but more detail, as you'd expect. If you don't want to deal with RAW, I'd say that it's worth using the multi-frame NR feature at high ISOs. Just keep in mind that you can't use it with RAW files, or if the D-Range Optimizer or HDR features are turned on.

Next up are the A55's numerous white balance controls. You have the usual presets, each of white can be fine-tuned to your heart's content. The custom option lets you use a white or gray card for accurate color in unusual lighting. You can also set the color temperature (2500K - 10000K), and that too can be fine-tuned in the green or magenta direction. And, as I mentioned earlier, the A55 also allows you to bracket for white balance.

The SLT-A55 also has a pair of dynamic range enhancement functions. The first is the D-Range Optimizer, which has been around for several years now. Simply put, this breaks the image down into smaller segments, and adjusts the contrast for each of them individually. You can set it to automatic, or adjust it manually, from level 1 to 5. Here's an example:

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Auto DRO
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There's almost no difference between the Auto and Off settings, at least in this example. Throw things into manual mode, however, and the shadows begin to brighten quickly. The DRO feature has little-to-no effect on highlight clipping, though. For that, you'll want to try out this next feature!

The Auto HDR feature can be quite handy when you have a lot of contrast in an image. This will take three photos in rapid succession -- one normally exposed, one underexposed, and another overexposed -- and then combine them into a single image. This allows for brighter shadows and less highlight clipping. As with the DRO feature, you can set it to auto, or manually adjust the exposure interval from 1EV to 6EV. Do note that you cannot use the HDR feature in the Auto modes, or when the RAW image format is selected. In addition to the HDR image, the A55 also saves a JPEG with everything (read: DRO) turned off. Here's an example:

Regular photo (DRO/HDR off)
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HDR Auto
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The differences here are quite obvious. The regular photo has highlight clipping in several places, and the sky is not as blue as it was in reality. The HDR photo dramatically cuts down on the blown highlights, while returning the sky to a more natural blue. The whole HDR process is quick and painless, so it's certainly worth doing in situations where highlight clipping is likely.

Adjusting the sharpness parameter of a Creative Style

The last thing to mention in the Function menu is Creative Styles. The A55 has six preset Creative Styles (and strangely, no custom options), such as vivid, portrait, and black & white. You can adjust the sharpness, saturation, and contrast for each of these (a noise reduction setting would've been nice). One thing I don't care for is how each of the presets has their parameters set to zero, so you can't really compare the difference between each of them.

Okay, back to the tour! Below that Function button is the four-way controller, used mainly for menu navigation and reviewing photos you've taken. The controller is also used the following:

  • Up - Display (toggles info shown on LCD/EVF)
  • Down - ISO sensitivity (described above)
  • Left - Drive (described above)
  • Right - White balance (described above)
  • Center - Activate AF / Select AF point + Set/OK

The last buttons to see on the back of the camera are for entering playback mode and deleting a photo. In record mode, the delete photo button is also what you'll press to activate the manual focus frame enlargement feature, as well.

Top of the Sony Alpha SLT-A55

You'll find plenty of additional buttons and dials on the top of the camera. Let's start with the mode dial on the far left of the photo, which has these options:

Option Function
Auto mode A regular point-and-shoot mode, without auto scene selection. Most menu options locked up, which includes exposure compensation, ISO sensitivity, and white balance.
Auto+ mode Point-and-shoot but with auto scene selection. The camera can also use multi-shot modes like Auto HDR, continuous shooting, handheld twilight, and more. Same restrictions as above.
Program Auto mode Still point-and-shoot, but now with full access to all camera settings. The A55 lacks a Program Shift feature.
Aperture priority mode You choose the aperture, and the camera picks appropriate shutter speed. Range depends on lens used. For the 18 - 55 mm kit lens, the range is F3.5 -F36.
Shutter priority mode You choose shutter speed, and the camera selects the proper aperture. Shutter speed range is 30 - 1/4000 sec.
Full manual (M) mode Choose both the shutter speed and aperture yourself (same ranges as above). A bulb mode will keep the shutter open for as long as the shutter release is pressed.
Continuous Advance Priority mode The SLT-A55 will shoot at up to 10 fps while adjusting the focus and exposure between each photo.
Sweep Shooting I told you about this cool feature earlier.
Scene selection You pick the situation, and the camera uses the appropriate settings. Choose from portrait, sports action, macro, landscape, sunset, night view, handheld twilight, night portrait).
Flash off Does just as it sounds. Also disables the AF-assist function of the flash.

The SLT-A55 has two auto modes: one vanilla, and the other fully loaded. The Auto+ mode not only has automatic scene selection -- it'll do things like Auto HDR, handheld twilight, and continuous shooting, if it thinks they're necessary. Something I don't like about the two auto modes is that you cannot adjust basic settings like white balance, ISO sensitivity, or exposure compensation.

Naturally, the A55 has a full set of manual controls, though I was surprised to see that it lacks a Program Shift function. There's no custom spot on the mode dial, either, which would've been a nice touch.

The Continuous Advance Priority mode is where the A55 can really strut its stuff. In this mode you can shoot at a whopping 10 frames/second, with the camera adjusting the focus and exposure between each shot. No other D-SLR in the world can do that at these speeds, as far as I know. Below is a table that summarizes all three of the burst modes on the SLT-A55:

Quality setting Continuous low Continuous high Continuous advance priority
RAW+JPEG 22 shots @ 2.9 fps 19 shots @ 6.7 fps 18 shots @ 9.7 fps
RAW 25 shots @ 2.9 fps 20 shots @ 6.6 fps 19 shots @ 10.0 fps
JPEG (Large/Fine) Unlimited @ 2.9 fps Unlimited @ 6.8 fps 29 shots @ 10.0 fps
Tested using a Panasonic Class 10 SDHC card

Well those are some very impressive numbers! I do have a couple of notes for you about these modes. First, I found that the image on the LCD and EVF keep up quite well with the action, so tracking a moving subject should be easy. If you're shooting RAW or RAW+JPEG, you can expect the LCD/EVF to black out for about 20 seconds after you take a burst, during which time you can't do anything. When the screen comes back on you can start taking photos again, though the camera will be sluggish until it finishes flushing the buffer memory (which takes close to a minute). In Continuous Advance Priority mode you cannot adjust the ISO, shutter speed, or aperture while the AF mode is set to continuous. However, if you set it to single AF, the ISO can be adjusted, and a Program Shift feature allows you to flip through various aperture/shutter speed combinations (why this isn't in the regular Program mode is beyond me).

The next stop on the tour is the camera's hot shoe, right at the center of the above photo. Sony is still using the same, somewhat proprietary hot shoe connector that was developed by Minolta. While it works just great with Sony and Minolta flashes, you'll have to buy a pricey adapter if you want to use a "standard" external flash. Speaking of Sony flashes, they'll work best with the A55, as they'll be able to "talk" to the camera's metering system. With a non-Sony flash, you'll probably have to adjust everything manually. if you're using the HVL-F42AM or HVL-F58AM flash, you'll be able to use them at any shutter speed that you wish. Otherwise, the limit is 1/160 sec.

Straddling that hot shoe (and hard to see in my photo) are the A55's small stereo microphones. If you want better sound recording, then you'll almost certainly want to pick up an external microphone.

Continuing to the right, you can see the camera's speaker, which has a button for switching between the EVF and LCD (if you're not using the eye sensor). Next to that is a button for the D-Range Optimizer that I told you about earlier. I would gladly trade that button for a second command dial.

The last thing to see on the top of the SLT-A55 is the shutter release button, which has the power switch wrapped around it.

Side of the Sony Alpha SLT-A55

Here's one side of the SLT-A55, which is mostly where you'll find the camera's I/O ports. But first, I should point out the two AF/MF switches (one on the body, the other on the lens) and the release for the built-in flash.

The I/O ports can be found at the far right of the photo, and are divided into three compartments -- all protected by plastic covers. The ports include:

  • HDMI
  • USB
  • Microphone
  • Remote control

The HDMI port is your only way to output video on the A55, as it does not support traditional composite video output.

The 18 - 55 mm kit lens is at the full wide-angle position here.

Side of the Sony Alpha SLT-A55

There's nothing to see on the opposite side of the camera, unless you count the strap mount. The kit lens is at its full telephoto position here.

Bottom of the Sony Alpha SLT-A55

On the bottom of the camera you'll find the battery/memory card compartment and a metal tripod mount. The door that covers this compartment is of average quality, and features a locking mechanism. Accessing the compartment while the camera is on a tripod is not an issue.

The included NP-FW50 lithium-ion battery can be seen at right.