DCRP

Sony Alpha SLT-A55 Review

Using the Sony Alpha SLT-A55

Record Mode

The Alpha SLT-A55 is ready to start taking photos a fraction of a second after you flip the power switch.


A live histogram is one of many things that can be displayed on the LCD or EVF

One of the promises of the SLT-A55's translucent mirror design is super-fast autofocus in live view, and Sony has certainly delivered the goods in that department. The A55 feels like it focus instantly in most situations. Expect focus lock in 0.1 - 0.3 seconds at wide-angle and about twice that at telephoto (depending on the lens, of course). The only time the camera struggled a bit was when there wasn't a lot of contrast in the scene, but it still managed to focus. Low light focusing is very good, even without the flash popped up for some AF assistance. What I'm getting at is that focus times will rarely exceed one second, in any situation.

Shutter lag isn't an issue, nor would I expect it to be.

Shot-to-shot speeds were around a second, regardless of the image quality setting, or whether you're using the flash. Nice!

To delete a photo you just took by pressing the (get ready) delete photo button!

Now let's take a look at the image size and quality options on the SLT-A55. This is the abridged version, covering only the default 3:2 aspect ratio.

Resolution Quality Approx. file size # images on 4GB SDHC card (optional)
Large (16 MP)
4912 x 3264
RAW+JPEG 25.5 MB 157
RAW 17.9 MB 223
Fine 7.2 MB 555
Standard 5.1 MB 790
Medium (8.4 MP)
3568 x 2368
Fine 4.5 MB 898
Standard 3.2 MB 1250
Small (4.0 MP)
2448 x 1624
Fine 2.8 MB 1415
Standard 2.2 MB 1802

As you can see, you can take a RAW image alone, or along with a large-sized JPEG. I suppose I should also remind you that the RAW format cannot be used in sweep panorama or handheld twilight mode.


A very brief description of each option can be displayed

If you've used the menu systems from Minolta cameras of yesteryear, then you'll feel right at home on the Alpha SLT-A55. The menus aren't flashy, but they're still attractive and fairly easy-to-navigate (though they went a bit overboard with tabs, in my opinion). If you hover over any menu option for a few seconds, a little help bubble pops up with a description -- always a nice thing to have. As I mentioned, the menu is divided up into tabs (and lots of them), covering recording, custom, playback, memory card, clock, and setup options. Here's the full list of what you'll find in the A55's menu system:

Recording menu
  • Image size (see chart)
  • Image aspect ratio (3:2, 16:9)
  • Image quality (RAW, RAW+JPEG, fine, standard)
  • Movie: file format (AVCHD, MP4)
  • Movie: size (1920 x 1080, 1440 x 1080, 640 x 480) - first option is for AVCHD, second and third for MP4
  • Movie: audio recording (on/off)
  • SteadyShot (on/off) - there are no options for things like panning, just on or off
  • Panorama: size (Standard, wide)
  • Panorama: direction (Right, left, up, down)
  • 3D panorama: size (16:9, standard, wide)
  • 3D panorama: direction (Right, left)
  • Flash control (ADI, pre-flash TTL)
  • AF illuminator (on/off)
  • Color space (sRGB, AdobeRGB)
  • Long exposure NR (on/off)
  • High ISO NR (Auto, weak) - options are kind of limited here

Custom menu

  • Eye-Start AF (on/off) - whether the camera focuses when you put your eye against the EVF
  • Finder/LCD setting (Auto, manual) - whether the eye sensor is used to activate the EVF
  • AEL button (Hold, toggle) - how this button works
  • Focus hold button (Focus hold, DOF preview) - for lenses that have such a thing
  • Focus magnifier (on/off) - whether pressing the delete photo button enlarges the frame
  • Redeye reduction (on/off) - fires the flash before a photo is taken to reduce redeye
  • Release w/o lens (Enable, disable) - whether you can take a photo without a lens attached
  • Grid line (Off, rule of thirds, square, diagonal + square)
  • Histogram (on/off)
  • Display rec. data (Live view, viewfinder) - I'm still trying to figure this one out
  • Auto review (Off, 2, 5, 10 secs)
  • Auto+ continuous advance (on/off) - whether the camera will automatically shoot a burst of photos in Auto+ mode
  • Auto+ image extract (on/off) - whether the camera saves all images taken in a burst or only an "appropriate" one

Playback

  • Delete (Multiple images, all in folder)
  • Still/movie select (Still, movie) - a mind-bogglingly dumb option -- why can't you see your stills and movies at the same time?
  • Slide show
    • Repeat (on/off)
    • Interval (1, 3, 5, 10, 30 secs)
    • Movie type (All, AVCHD, MP4) - only shown when viewing movies
    • Image type (All, 3D only) - only shown when viewing images
  • Image index (6, 12 images) - how many photos fit on the thumbnail screen
  • 3D viewing - if I had a 3D TV, then I'd tell you what this does
  • Protect
  • Specify printing
    • DPOF printing (Multiple images, cancel all)
    • Date imprint (on/off)
  • Volume settings (0 -7)
  • Select folder
  • Select date - for movies only
  • Playback display (Auto rotate, manual rotate)

Memory Card Tool menu

  • Format
  • File number (Series, reset)
  • Folder name (Standard, date)
  • Select REC folder
  • New folder
  • Recover image DB - if you're having trouble playing back images
  • Display card space - displays how many photos or movies can be taken at the current settings

Clock setup menu

  • Date/time setup
    • Daylight savings (on/off)
    • Date/time
    • Date format
  • Area setting - choose your time zone
Setup menu
  • LCD brightness (Auto, manual, sunny weather) - the manual option lets you select from -2 to +2
  • Viewfinder brightness (Auto, manual)
  • GPS settings
    • GPS power (on/off)
    • GPS auto time correction (on/off) - uses the GPS signal to set the clock
    • Use GPS assist data (on/off) - use the data sent over from the PMB software to reduce satellite acquisition times
    • Delete GPS assist data
  • Power save (10, 20 secs, 1, 5, 30 mins) - how long the camera is idle before powering off
  • Control for HDMI (on/off) - whether the camera can be controlled with your HDTV remote control when connected via HDMI
  • Language
  • Help Guide display (on/off) - gives menu hints and describes shooting modes when you rotate the mode dial
  • Upload settings (on/off) - turns the transmitter in Eye-Fi cards on and off
  • USB connection (Mass Storage, PTP)
  • Audio signals (on/off)
  • Cleaning mode - manually activates the dust removal system
  • Version
  • Demo mode (on/off)
  • Reset default

Believe it or not, there's just one thing from the menu that I want to talk about, and that's the SLT-A55's GPS feature. As with Sony's compact cameras, the A55's GPS feature runs quietly in the background. There's no real interface to it -- just on or off. You can't see your current location and, no, there's no built-in database of landmarks. But the system works well, with acquisition times of roughly 10 seconds with the assist data loaded. In addition to tagging your location, the GPS can be used to set the date and time on your camera automatically.

And that's it for menus -- let's talk photo quality now! I used the 18 - 55 mm kit lens for all of these, except for the night shot.

I've got no complaints about how the SLT-A55 handled our usual macro test subject. The colors are nice and saturated, with the camera handling my studio lamps without any trouble. The figurine has the "smooth" look that is typical of D-SLRs, though plenty of detail is still captured. I don't see any evidence of noise, and I sure as heck wouldn't expect to.

Obviously, the minimum focus distance will depend on what lens you're using. For the 18 - 55 mm kit lens, that distance is 25 cm. Serious close-up photographers may want to consider one of the three dedicated macro lenses that Sony sells.


I busted out the monstrous F4.0-5.6, 70 - 400 mm Sony lens for the night test shots. This turned out to be a pretty nice lens, as it helped produce a nice and sharp photo of the San Francisco skyline. The buildings all have clearly defined edges, and noise levels are low. There's some highlight clipping here, but it's not too bad. Noise levels are very low, as you'd expect. One thing I do see here is purple fringing, which is usually related to the lens, rather than the camera itself.

Now let's use that same scene to see how the A55 performed at higher sensitivities!


ISO 100

ISO 200

ISO 400

ISO 800

ISO 1600

ISO 3200

ISO 6400

ISO 12,800

You'd be hard-pressed to spot the difference between the first three crops, though there's a slight increase in noise at ISO 400. Things start to get a little blotchy at ISO 800, but it shouldn't reduce your output sizes by too much. That changes at ISO 1600, so that might be a good time to start thinking about shooting RAW (see below for examples). There's a fair amount of detail loss at ISO 3200, and even more at the two sensitivities above that (which you'll probably want to avoid altogether in low light).

Let's take the ISO 1600 and 3200 images and see if we can't clean them up a bit with some easy post-processing!

ISO 1600

JPEG, straight out of the camera

RAW -> JPEG conversion (Adobe Camera Raw)

RAW -> JPEG conversion + NeatImage + Unsharp Mask
 
ISO 3200

JPEG, straight out of the camera

RAW -> JPEG conversion (Adobe Camera Raw)

RAW -> JPEG conversion + NeatImage + Unsharp Mask

I should preface this by saying that I don't consider myself an expert in RAW processing. Even with my skill set, I was able to pull back a lot of the detail that noise reduction smudged away by spending maybe 30 seconds running each image through Photoshop. I think the highlights look a bit better in the RAW conversions, as well.

I'll give you another example of "RAW in action" in a moment.

There's moderate barrel distortion at the wide end of the 18 - 55 mm Sony kit lens. You can see this in the real world by looking at the flagpole on the left side of this photo. I didn't find vignetting (dark corners) or corner blurring to be issues with this lens.

The SLT-A55 can fire its built-in flash to shrink the pupils of your subject(s), reducing the risk of redeye. As you can see, redeye was not a problem in our test. If you do encounter some, you'll have to fix it on your computer, as there's no digital removal system to be found on the A55.

Now it's time for our studio ISO comparison. Since the lighting is always the same, you can compare these photos with those taken with other cameras I've reviewed over the years. The very high resolution of the SLT-A55 means that you're only seeing a small portion of the test scene below, so be sure to view the full size images too! And with that, let's take a look at how the A55 performed at various sensitivities in normal lighting:


ISO 100

ISO 200

ISO 400

ISO 800

ISO 1600

ISO 3200

ISO 6400

ISO 12,800

First off, I have no idea why the lower part of the test image looks soft. I didn't notice this in my real world photos, so I'm going to assume that it's some kind of fluke. As for noise, you won't see any through ISO 800. Noise does make an appearance at ISO 1600, though it's not bad enough to keep you from making midsize or large prints. Even the ISO 3200 and 6400 photos are usable for small prints, especially if you're shooting RAW. As for ISO 12,800, you're losing a fair amount of detail, and there's a drop in color saturation, as well. I'd pass on that one unless you're really desperate.

I already showed you how using the RAW image format can improve your high ISO sensitivity night shots. Let's do it all over again for the ISO 6400 and 12,800 images from above:

ISO 6400

JPEG, straight out of the camera

RAW -> JPEG conversion (Adobe Camera Raw)

RAW -> JPEG conversion + NeatImage + Unsharp Mask
 
ISO 12,800

JPEG, straight out of the camera

RAW -> JPEG conversion (Sony IDC)

RAW -> JPEG conversion + NeatImage + Unsharp Mask

Two words: huge improvement. If you're shooting at high ISOs, then I'd highly recommend using the RAW format, as the A55's noise reduction system is clearly heavy-handed at those sensitivities. Naturally, you get more grain-style noise, but I'd say it's worth the trade-off, wouldn't you?

Overall, I was quite impressed with the photo quality on the SLT-A55. The one real negative is related to the camera's metering system which, more often than not, overexposed by 1/3 to 1/2 a stop. I ended up having to reshoot most of my Stanford photos because of this. My advice: bracket! The A55 is a bit of a highlight clipper, as well. Colors were pleasing, and photos have the "smooth" look that is a common trait of digital SLRs. The A55 does a good job of keeping noise levels low until you reach the midrange sensitivities (ISO 800 or so), and even then, things don't get really smudged until the very highest settings. As the previous example illustrated, you'll almost certainly want to shoot RAW when you get to ISO 3200 and above. The A55 did have some issues with purple fringing with both lenses I tested. I blame the lenses more than the camera, but it's still worth noting.

Now, I invite you to have a look at our SLT-A55 photo gallery. View the full size images, print a few if you can, and then decide if the photo quality meets your expectations!

Movie Mode

One of the big features on the SLT-A55 is its ability to record Full HD movies. That means that you can record video at 1920 x 1080 at 60 interlaced fields/second (though the sensor output is 30p) with Dolby Digital Stereo sound. The camera uses the AVCHD format (common on HD camcorders), and since it's outputting video at a standard frame rate, it should be fairly easy to edit. In theory, the camera can keep recording video at that setting until 29 minutes have elapsed. However, that's with SteadyShot turned OFF, at 68 degrees Fahrenheit. With SteadyShot turned on (or at higher ambient temperatures), the recording time drops precipitously, down to as little as 9 minutes. That's a bit disappointing. As you might imagine, Sony recommends a high speed memory card for HD movie recording.

Added comment about 30p sensor output on 3/20/11

Don't need Full HD video? Then you can downsize to 1440 x 1080 or 1280 x 720 (both at 30 fps). When you do that, you're also switching from the AVCHD codec to MPEG-4, which is a easier to both edit and share on your PC. Both of those will stop recording when the file size hits 2GB or the recording time reaches 29 minutes (again, dependent on whether you're using the IS system).

Obviously, you can zoom in and out all you want while the camera is recording video (though the kit lens is very jerky when you adjust it). When using continuous AF, the camera is able to refocus very quickly as you pan around, or if you subject moves. After taking a lot of test videos, I found that the camera isn't responsive enough to keep up with fast-moving subjects. However, if you're panning the camera from one thing to another, the camera does indeed refocus quickly (see this example). With wide AF, the camera will change focus points automatically -- to do so manually, use local AF. The image stabilizer is available, but as I mentioned, using it reduces your recording time considerably.

Preceding paragraph updated with example on 11/28/10

The SLT-A55 does not offer any manual controls in movie mode. You can adjust the exposure compensation, but that's it. A wind cut filter or manual audio level adjustment feature would've been nice, as well.

I have two sample movies for you, which I took at the Full HD setting. I converted the movies from AVCHD to H.264 format using Toast Titanium 10. If you want, you can download the original MTS files and view those instead.


Click to play movie (1920 x 1080, 30 fps, 32.5 MB, QuickTime/H.264 format)
Click to download original MTS file (44.3 MB)


Click to play movie (1920 x 1080, 30 fps, 14.9 MB, QuickTime/H.264 format)
Click to download original MTS file (17.7 MB)

Playback Mode

For being a camera targeted toward consumers, the SLT-A55's playback mode feels a bit too stripped-down. The basics are all here, including slideshows, DPOF print marking, image protection, thumbnail view, and playback zoom.

Photos can be viewed one at a time, or on thumbnail pages containing either six or twelve pictures. One incredibly dumb thing on the SLT-A55 is that you can't view stills and movies at the same time -- you either have to go to the menu to switch, or zoom out to thumbnail view and change the "tab" from one to the other.

There are no editing features on the camera, unless you count image rotation. There are no tools for trimming or grabbing frames from movies you've recorded, either.

By default, the camera doesn't show you much information about your photos, but press "up" on the four-way controller and you'll get a lot more, including multiple histograms.

The SLT-A55 moves from photo to photo instantly in playback mode. The only time I noticed a slowdown was when the camera was still saving a burst of images to the memory card.

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