Review Date: July 4, 2011
Category: Family DSLR – Beginner Amateur
Sony SLT-A35
IMAGE QUALITY
The Sony Alpha SLT-A35 is a Single Lens Translucent (SLT) camera with lightning-fast autofocus in Live View. It has 16.2 megapixel resolution on an Exmor™ APS HD CMOS sensor (23.4 X 15.6mm). It is positioned as an entry-level Family DSLR camera and accepts interchangeable lenses on the Sony A-mount.
What makes the SLT-A35 different from other traditional DSLRs is its translucent mirror. On traditional mirrored DSLR, the mirror flips down to direct light up to the optical viewfinder (and the Phase-Difference AF sensor) and then flips up to get out of the way and allow light to expose the image sensor.
The mirror in the SLT-A35 is fixed in the down position. It does not flip up and down because it does not need to. Instead the mirror is translucent, i.e. it is semi-transparent and lets most of the light in to expose the image sensor but a small part of it is reflected up to the Phase-Difference AF sensor.
This is a very clever implementation because it takes care of a major problem that DSLRs using the traditional mirror suffer from: in Live View, the mirror is flipped up and so the Phase-Difference AF sensor cannot be used for autofocus; instead, they need to use Contrast-Detection for focusing and this is generally so painfully slow as to be impractical. Because the SLT-A35 uses a fixed translucent mirror that is always reflecting part of the light to the Phase-Difference AF sensor, its autofocus in Live View is full-time and lightning-fast. And because the SLT-A35 uses an electronic viewfinder, the view is always bright, clear and precise.
The Sony SLT-A35 has very good image quality (including very good low-light performance) up to ISO 800 with plenty of detail preserved and good colors, with very usable ISO 1600 and usable ISO 3200. Higher ISOs suffer from noise and detail loss.
| Sony 18-55mm 3x Optical Zoom |
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| Wide-angle 18mm (27mm, 35mm equivalent) |
Telephoto 55mm (82.5mm, 35mm equivalent) |
One of the many advantages of a DSLR is the ability to use interchangeable lenses suited for specific jobs. The Sony SLT-A35 comes with a Sony 18-55mm f/3.5-5.6 Lens as standard kit lens, which provides a 27-82.5mm equivalent field of view. In the above pictures, we show the coverage for 27mm and 82.5mm (35mm equivalent).
The Sony 18-55mm f/3.5-5.6 lens has a max. aperture of f/3.5(W)-5.6(T) and min. aperture of f/22(W)-f/36(T). It has 7 blades (Circular aperture) and accepts 55mm diameter filters.
The Sony SLT-A35 has full exposure flexibility with PASM modes (there is no Program Shift).
The camera also provides exposure compensation (with Auto Bracketing), Custom (Manual) White Balance and WB Bracketing. A Histogram can be displayed in both Live and Playback modes.
Shutter speed ranges from 1/4,000-30 sec. in PASM, plus B in Manual Mode.
Macro
The actual macro capability is a function of the lens you use. The Sony 18-55mm kit lens allows you to focus as close as 25cm (9.84 in.). AF locks precisely and fast.
The AF Area can be manually moved to any of 15 points [simply press the AF button and use ARROWS or the Command Dial to move the AF point], but not to the edges of the screen. There does not seem to be a quick way to return to center.
There are three metering modes: Multiple (Multi-Segment), Center Weighted and Spot.
| Auto White Balance Indoors | |
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| AWB | Custom WB |
As the above two pictures show, the Auto White Balance (AWB) is pretty accurate indoors under artificial lighting [I have two energy-saving fluorescent light bulbs on the ceiling]. Manual WB is easy to set and provides very good results. In bright natural light, AWB works very well.
| ISO Comparisons | |
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| ISO 100 | |
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| ISO 200 | ISO 400 |
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| ISO 800 | ISO 1600 |
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| ISO 3200 | ISO 6400 |
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| ISO 12800 | |
The Sony SLT-A35 has 8 ISO settings going from ISO 100 to ISO 12800, and 25600 with the Multi-Frame NR function. You can also set the max. ISO the camera will use. The 100% crops above (area delimited by the white square) demonstrate the noise at the available ISO Speeds. At ISO 100 to 800, noise is under control. Noise starts to be slightly visible at ISO 1600 but is still very acceptable, with ISO 3200 also quite usable in smaller prints or for Web only display. Loss of detail is apparent at ISO 6400, and noise (with detail loss) is quite visible at higher ISOs. Overall, very good noise handling.
CA (Purple Fringing)
CA is under control in everyday shots and is very slight in high contrast shots. The corner delimited by the red square at bottom left, and reproduced at 100% crop at bottom right, shows slight purple fringing.
Long Exposure - 55mm, Shutter-Priority, Pattern, 30 sec., F10, ISO 100, Custom WB, Self-timer, Tripod Used
Our Long Shutter Speed test is a torture test for digital cameras. Here we test whether (and how well) a camera can lock focus, provide accurate WB and obtain a correct exposure in extreme low light situations. The Sony SLT-A35 with its Phase-Detect AF passes this test quite easily.
The Sony A35 allows the use of a long shutter speed of up to 30 sec. in PASM modes, therefore allowing very nice night photography. Generally, with image sensors, noise usually becomes more prominent at slow shutter speeds. You can turn Noise Reduction ON in MENU – 3 – Long Exposure NR – ON; you’ll notice a longer processing time (approx. twice as long) before the next picture can be taken.
To test this noise reduction algorithm, we take a low-light indoors shot. I experiment a bit to obtain the optimum exposure, eventually settling on 30 sec. at F10. Even at this long shutter speed, the Sony A35’s noise reduction seems to be working great, producing a nice smooth blurring effect of the background.
The Sony A35 allows you to save an image in the RAW file format. I was able to take max. 7 RAW images in 2.5 sec. (@ 2.8fps) in Continuous Shooting Lo and 6 RAW images in 2 sec. (@ 3fps; note that this is slower than the stated 5.5fps) in Continuous Shooting Hi. It takes about 3 sec. to write a RAW image to memory card (I used a regular 16GB SDHC SiliconPower card). Note that these times do not include the extra processing times you’ll experience if Noise Reduction kicks in. You can also select to save a RAW+JPEG.
I was able to take 46 JPEG Fine images in 17 sec. (@ 2.7fps) in Continuous Shooting Lo, 3 JPEG Fine images in 1 sec. (@ 3fps) in Continuous Shooting Hi, when the buffer fills up and the speed slows down.
I set the camera to ISO 1600, shutter speed 1/160 sec., Picture Size Fine, and everything else pretty much turned off. Your performance times may vary depending on your camera settings.
At Picture Size = Fine, a 16.2MP JPEG image is compressed down to anywhere between 2.6MB and 9.6MB. A RAW image occupies about 16.5MB.
We find the overall image quality of the Sony SLT-A35 at ISO 100 to be excellent with good details in the shadows and highlights. Images up to ISO 800 are also low in noise. ISO 1600 to 3200 are very usable. Overall, very good image quality.
View the Sony A35 Photo Gallery [In the Photo Gallery, click on the picture of the camera to return here.]
Next: Sony A35 Handling & Feel