Sony Alpha SLT-A35
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Sony A35 Image Quality
Saturation & Hue Accuracy
Very good overall accuracy and saturation, with only minor shifts in hue and intensity.
Skin tones. Here, when adjusted for the correct white balance, the Sony A35 did well, producing natural-looking skin tones. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.
Hue. The Sony A35 did push cyan toward blue, red toward orange, orange toward yellow and yellow toward green, but shifts were relatively minor. (The cyan to blue shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors.) With an average "delta-C" color error of only 4.73 after correction for saturation, overall hue accuracy was very good; much better than average. Hue is "what color" the color is.
The Sony A35 offers six preset "Creative Style" options. You can adjust contrast, saturation, and sharpness for any of the settings.
|Creative Style Options|
Mouse over the links above to see the effect of the presets on our Still Life target. Click on a link to load the full resolution image.
The Sony A35 has a total of seven saturation settings available, three above and three below the default saturation. This covers a pretty wide range of saturation levels, about as wide a range as you're likely to find photographically relevant, apart from special effects that are arguably better achieved in software. The fine steps between settings mean you can program the camera to just the level of saturation you prefer, a feature we look for in cameras. Saturation also had little effect on contrast, which is how it should work.
|Saturation Adjustment Examples|
The table above shows results with five of the seven saturation settings, including the default and the two extremes. Click on any thumbnail above, then click again to see the full-sized image.
|See full set of test images with explanations
See thumbnails of all test and gallery images
Exposure and White Balance
Indoors, incandescent lighting
Very warm cast with Auto, but good color with the Incandescent and Manual settings. About average amount of positive exposure compensation required.
|Auto White Balance
|Incandescent White Balance
|Manual White Balance
Indoors, under normal incandescent lighting, color balance was overly warm with the Auto white balance setting. Results with the Incandescent setting were quite good, just slightly warm. The Manual setting was very accurate, though some may prefer Incandescent because it conveys a touch more of the warmth of the original lighting. The 2,600 Kelvin setting which matches the color temperature of our lights resulted in a slightly cool, bluish image. The Sony A35 required +0.3 EV positive exposure compensation here, which is average for this shot. (Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.)
Excellent results under harsh lighting, with good handling of contrast, color, and exposure.
|Manual White Balance,
|Auto White Balance,
Outdoors, the Sony A35 performed very well. No exposure compensation was required to keep the model's face reasonably bright in our "Sunlit" Portrait shot. The average among the cameras we've tested is +0.7 EV, so the A35 performed much better than average here. Contrast is a little high, as you might expect under such harsh lighting, but the camera does an excellent ob of holding onto detail in both the deep shadows and bright highlights, even without the help of Dynamic Range Optimization (DRO was off for these shots). Color balance was quite good, though Auto white balance rendered the model's face a touch too pink. We preferred results from the Manual white balance setting. Default exposure was quite good for our Far-field shot as well, with very few highlights blown, again with DRO disabled. Some very dark shadows in the leaves were lost, but the camera kept the main subject well exposed, so that's to be expected. The Far-field shot using Auto white balance had very good color. Overall, an excellent performance in harsh lighting.
Very high resolution, 2,100 ~ 2,200 lines of strong detail.
|Strong detail to
2,200 lines horizontal
|Strong detail to
2,100 lines vertical
|Strong detail to
2,200 lines horizontal
ACR converted RAW
|Strong detail to
2,100 lines vertical
ACR converted RAW
In camera JPEGs of our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,200 lines per picture height in the horizontal direction, and about 2,100 lines per picture height in the vertical direction. Complete extinction of the pattern didn't occur until about 2,800 to 3,000 lines. When converting the matching RAW files, Adobe Camera Raw wasn't able to extract significantly more detail here, so the Sony A35 is doing a very good job holding on to high contrast detail at base ISO. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.
Sharpness & Detail
Good detail, though fine detail is a little soft, with some minor edge-enhancement on high-contrast subjects. Moderate noise suppression visible in the shadows and areas of low contrast.
|Good definition of high-contrast
elements with some minor sharpening
artifacts. Fine detail is a little soft.
|Subtle detail: Hair
Noise suppression tends to blur
detail in areas of subtle contrast.
Sharpness. The Sony A35 captures fairly detailed images overall, though results are somewhat soft at default settings, despite using the very sharp Carl Zeiss 24-70mm F/2.8 SSM lens at f/8 for the shot above left. There are some minor but visible edge enhancement artifacts on high-contrast subjects such as the larger tree branches in the image. Fine detail such as the smaller branches and pine needles show very little edge enhancement, but appear a touch mushy due to slightly over-zealous noise reduction even at base ISO. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.
Detail. The crop above right shows moderate noise suppression in the darkest areas of the model's hair. Some individual strands are smudged together, though quite a few strands are still visible despite the low contrast subject. We saw similar results with fine detail in the pine needles shows. Still, pretty good results here for a 16-megapixel APS-C sensor at base ISO, though we wish Sony provided more control over noise reduction. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.
RAW vs In-Camera JPEGs
As noted above, the Sony A35 produces fairly detailed in-camera JPEGs, though fine detail is a touch soft. Quite a bit more detail can often be obtained from carefully processing RAW files with a good RAW converter.
In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking on the link will load the full resolution image. Examples include (from left to right): an in-camera Fine JPEG, RAW file processed through Sony's Image Data Converter SR version 3.2 software at default settings, another processed with IDC's sharpening turned up to +100 and its overshoot and undershoot sliders set to +50, and finally the same RAW file converted with Adobe Camera Raw 6.5 beta, then sharpened in Photoshop using unsharp mask at 300% with radius 0.3.
As you can see, the Sony IDC version at default settings is somewhat softer than the in-camera JPEG. (Color rendering is also slightly different.) Increasing the sharpening settings gave the image a crisper look and helped extract a bit more detail, though noise reduction is still blurring fine detail. The Adobe Camera Raw conversion showed the most detail, but also revealed more noise. You can always turn up the luminance noise reduction (default of zero was used here), or process the files in your favorite noise reduction program or plugin, though. Bottom line: as is usually the case, the Sony A35 rewards RAW shooters with better detail than JPEGs when used with a good RAW converter.
ISO & Noise Performance
Competitive noise performance for a 16-megapixel APS-C sensor, with excellent results up to ISO 800, though slightly strong default noise reduction at higher ISOs.
Default High ISO Noise Reduction
|ISO 100||ISO 200||ISO 400|
|ISO 800||ISO 1,600||ISO 3,200|
|ISO 6,400||ISO 12,800|
The Sony A35's images are quite clean and detailed at ISO 100 and 200, and ISO 400 is almost as good. Some noise "grain" is noticeable at ISO 800, and there's a bit of chroma noise in the shadows, but the camera does a good job at holding on to fine detail here. There's some stronger smudging of fine detail at ISO 1,600, but the A35 still does well at this ISO for its resolution. At ISO 3,200, fine detail suffers from more aggressive noise reduction, but there is still some detail left, and chroma noise really isn't an issue. Detail takes larger hit at ISO 6,400 and especially at 12,800, where there's quite a bit of chroma noise in the form of purple and yellow blotches. Overall though, these are very good results considering the class and resolution offered, and an improvement over the A33. Unfortunately, Sony still doesn't offer much flexibility in noise reduction (only two levels: Auto and Weak. See below). As always, see the Print Quality section below for maximum recommended print sizes at each ISO.
A note about focus for this shot: We shoot this image at f/4, usually using one of three very sharp reference lenses (70mm Sigma f/2.8 macro for most cameras, 60mm f/2.8 Nikkor macro for Nikon bodies without a drive motor, and Olympus Zuiko 50mm f/2.0 for Four Thirds and Micro Four Thirds bodies). To insure that the hair detail we use for making critical judgements about camera noise processing and detail rendering is in sharp focus at the relatively wide aperture we're shooting at, the focus target at the center of the scene is on a movable stand. This lets us compensate for front- or back-focus by different camera bodies, even those that lack micro-focus adjustments. This does mean, though, that the focus target itself may appear soft or slightly out of focus for bodies that front- or back-focused with the reference lens. We know this; if you click to view the full-size image for one of these shots and notice that the focus target is fuzzy, you don't need to email and tell us. :-) The focus target position will have been adjusted to insure that the rest of the scene is focused properly.
High ISO NR = Weak
High ISO NR = Auto
Noise Reduction Oddity. The "Weak" high ISO NR setting smudges the red leave pattern in our Still Life target setting more than the "Auto" setting at higher ISOs. The Auto setting does reduce chroma noise compared to the Weak setting though (lower crops), and we confirmed the filenames are correct. We saw similar behavior with previous Sony models such as the NEX-5/3 and A55/A33.
Extremes: Sunlit and low light tests
Very high resolution with excellent highlight and shadow detail. Very good low-light performance, capable of capturing bright images in near darkness. Special modes make it possible to capture low-light images without a tripod.
|0 EV||+0.3 EV||+0.7 EV|
Sunlight. The Sony A35 handled the deliberately harsh lighting in the test above very well. We preferred the default, 0 EV exposure here, though some may prefer the slightly brighter skin-tones of the +0.3 EV exposure. Contrast is a little high, but shadow and highlight detail are both very good. Despite the apparent brightness, there are actually very few clipped highlights in the model's face and shirt (even at +0.3 EV), with most of the clipping occurring in specific color channels in the flowers, or in specular highlights where you'd expect clipping. There were only a few lost shadows, which is also very good. Still, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible. See below for results with Dynamic Range Optimization and High Dynamic Range features enabled.
Dynamic Range Analysis
A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)
What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work.
JPEG. The graph at right (click for a larger version) was generated using Imatest's dynamic range analysis for an in-camera Sony A35 JPEG file with a nominally-exposed density step target (Stouffer 4110). At the base ISO of 100 (the optimal ISO) with DRO and HDR settings turned off, the graph shows 10.6 f-stops of total dynamic range, with 7.91 f-stops at the "High" Quality level, with fairly gradual roll-offs at both the highlight and shadow ends of the tone curve. These are are very good results, almost as good as the best performers to date, such as the the Nikon D7000. Compared to the Sony A55 which uses the same or very similar sensor, the A35 scored slightly higher at the High Quality level (7.91 vs 7.74 f-stops), and also higher in total dynamic range (10.6 vs 9.8 f-stops). Note though that this measurement has a margin of error of about 1/3 f-stop, so differences of less than 0.33 can be ignored.
RAW. The graph at right is from the same Stouffer 4110 stepchart image captured as a RAW (.ARW) file, processed with Adobe Camera Raw using the Auto setting. (Slightly better results are likely possible with manually tweaking, but we weren't able to do much better.) As can be seen, the score at the highest quality level increased from 7.91 to 9.36 f-stops, which is almost a 1.5 f-stop improvement, while total dynamic range increased about one f-stop, to 11.5 from 10.6. Again, these results are very good, though not quite as good as the best APS-C sensors. (The Nikon D7000 for example managed 10.1 f-stops at the highest quality level, with 12.1 f-stops total dynamic range.) It's also worth noting here is that ACR's default noise reduction settings reduced overall noise somewhat (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the higher quality thresholds.
Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here. In actual shooting conditions, be sure to use fill flash in situations like the one shown here; it's better to shoot in open shade whenever possible.)
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. Just as with its saturation adjustment, the Sony A35's contrast setting meets both challenges.
|Contrast set to lowest,
|Contrast set to lowest,
At its lowest contrast setting, the SLT-A35 did a really excellent job of preserving highlight detail, maintaining natural-looking skin tones, and holding nice detail in the shadows. Overall, very good results here, especially when the contrast setting is tweaked. (This is a really tough shot; the Sony does a much better than average job handling it.)
|Contrast Adjustment Examples|
The table above shows five of the seven contrast setting, including the default and two extremes. It's pretty hard to evaluate small differences in contrast on small thumbnails like these, so click on any thumbnail to go to the full-size image.
One very nice feature of Sony's contrast adjustment is that it has very little effect on color saturation. Contrast and saturation are actually fairly closely coupled, it's a good trick to be able to vary one with out the other changing as well. Sony did a good job here.
Outdoor Portrait DRO Comparison
Dynamic Range Optimization is Sony's name for their dynamic range enhancement technology. DRO divides the image into small areas, analyzes the range of brightness of each area, and adjusts the camera's image processing parameters accordingly to make the best use of the available dynamic range. Auto DRO is enabled by default on the Sony A35. You can also set the level manually, from 1 ("weak") to 5 ("strong"), or turn it off. As one would expect, DRO is only available for JPEG files.
The above thumbnails and histograms show the effects of the various levels of DRO on our "Sunlit" Portrait shot with no exposure compensation. Mouse over the links to load the associated thumbnail and histogram, and click on the links to visit the full resolution image. As you can see from the thumbnails and associated histograms, DRO had only a slight effect on the highlights in this shot, with higher levels clipping just slightly more highlights. The bulk of the difference between different levels of DRO is found in the shadows and darker midtones. The stronger the DRO level, the more boost is applied to darker areas. That usually results in more visible noise in boosted areas of the image, but the A35 produces images with fairly low shadow noise, so increased noise wasn't really an issue even at the highest DRO levels. The default Auto DRO setting did a pretty good job here.
Above, you can see the effect of DRO settings on our Far-field House shot. The default Auto setting produced a good exposure overall, despite the harsh lighting.
High Dynamic Range. The Sony A35's HDR mode takes three images in rapid succession, one nominally exposed , one underexposed, and one overexposed, then combines them into one high dynamic range JPEG automatically. Lighter areas from the underexposed image are combined in-camera with darker areas from the overexposed image to produce an image with increased dynamic range. The camera then saves a single composite image, as well as the nominally exposed image. The overlaid images are micro-aligned by the camera, but it can only correct for so much movement. If it can't micro-align successfully, an icon indicating HDR capture failed will appear. For best results, the subject should not move or blink, so it's not really intended for portraits. There is also a manual mode where you can select 1 EV ("weak") to 6 EV ("strong") difference in exposures.
Mouse over the links to load the associated thumbnail and histogram, and click on the links to visit the full resolution image. As you can see, the Auto setting produced an image that looked flat and unnatural with this scene, similar to the 5 EV setting. The higher the setting, the more highlights were toned-down, and shadows opened up. The middle manual settings did a pretty good job at boosting shadows while reducing highlights, though there weren't many clipped highlights to begin with.
Above, you can see the effect of HDR settings on our Far-field House shot.
|Face Detection On
The Sony Alpha DSLR-A35 has the ability to detect faces, and adjust exposure and focus accordingly. As you can see above, the image with face detection enabled is much brighter with the face slightly overexposed, with highlights in the shirt and flowers quite hot. Auto+ exposure mode did a better job overall, automatically enabling DRO to brighten shadows without blowing many highlights.
Low Light. The Sony A35 performed well in our low light test, producing bright images down to the lowest light level we test at (1/16 fc) at all ISO settings. The metering system struggled a bit at very low light levels though, so we used manual exposure for these shots. Noise is very well controlled up to ISO 800, though as expected, at higher ISOs there are moderate to high amounts of fine luminance noise and some blotchy chroma noise. Auto white balance did a very good job here, producing a fairly neutral, just slightly cool color balance at all ISOs and light levels. There is just a hint of some horizontal banding at very high ISOs, but that's not uncommon. Hot pixels can be seen with long exposure noise reduction turned off (the second column from he right) at low ISOs, but they are few and far between. The right-most column shows the results with Multi-frame NR active. It works really well at reducing noise compared to a single frame, and allows ISO sensitivity to be expanded to 25,600 equivalent.
The camera's autofocus system was able to focus on the subject down to below the 1/16 foot-candle light level unassisted with our 70mm f/2.8 reference lens. That's excellent performance, and the SLT-A35 was able to focus in complete darkness with its built-in focus assist lamp enabled.
How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.
NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) Thanks to their phase-detect AF systems, digital SLRs like the Sony A35 tend to do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects. (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)
|Low Light Multi-frame NR|
|Manual, 1/4s, ISO 12,800||Multi-frame NR, 1/4s, ISO 12,800|
Multi-frame Noise Reduction. This feature is similar to Sony's Hand-held Twilight mode which shoots a burst of six images with a single press of the shutter button and combines all six images into one composite image with reduced noise. But unlike Hand-held Twilight, Multi-frame NR gives you control over the ISO, aperture and shutter speed used, so you may still need to use a tripod depending on the exposure parameters you select. (We frankly don't see the value to this mode when using a tripod, as selecting a lower ISO and longer shutter speed will produce a clean image as well.) As you can see, the image captured with Multi-frame Noise Reduction (right) is both more detailed and cleaner than the standard image (left) despite both being shot at ISO 12,800. An added bonus is that ISO 25,600 equivalent is available with MF NR.
Produces a good 20x30-inch print from ISO 100-400; ISO 3,200 images are better at 11x14; and ISO 12,800 can be counted on for a decent 5x7.
ISO 200 images look about the same at 20x30 inches, with only slight softening in red areas, hardly worth mentioning.
ISO 400 shots also look good at 20x30 inches, though contrast in reds begins to reduce more noticeably.
ISO 800 images still show good detail at 20x30 inches, though luminance noise dances in the shadows. Red areas in particular look better with size reduction to 16x20 inches, as do the shadows.
ISO 1,600 shots are very usable at 16x20 inches, with good control over shadow noise. There's a hint of softness overall, though, which tightens up at 13x19 inches.
ISO 3,200 images are good at 13x19 inches too, though detail in reds is considerably softer, such that we'll stop tracking it from here, as it gets worse faster than other areas. There's luminance noise in the shadows that's accompanied by blobs of chroma noise. Reduction to 11x14 reduces the influence of these factors.
ISO 6,400 shots are usable at 11x14, but shadows are a bit too murky. Everything but low-contrast reds looks good at 8x10.
ISO 12,800 are rough but usable at 8x10, but look quite nice at 5x7.
Overall an excellent performance from the Sony A35, tracking pretty well with most modern APS-C SLRs in the print quality department, with its highest ISO able to produce a good 5x7-inch print.
Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 Mark II studio printer, and the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)
Recommended Software: Rescue your Photos!
Just as important as an extra memory card is a tool to rescue your images when one of your cards fails at some point in the future. We get a lot of email from readers who've lost photos due to a corrupted memory card. Memory card corruption can happen with any card type and any camera manufacturer, nobody's immune. A lot of "lost" images can be recovered with an inexpensive, easy to use piece of software though. Given the amount of email I've gotten on the topic, I now include this paragraph in all my digital camera reviews. The program you need is called PhotoRescue, by DataRescue SA. Read our review of it if you'd like, but download the program now, so you'll have it. It doesn't cost a penny until you need it, and even then it's only $29, with a money back guarantee. So download PhotoRescue for Windows or PhotoRescue for Mac while you're thinking of it. (While you're at it, download the PDF manual and quickstart guide as well.) Stash the file in a safe place and it'll be there when you need it. Trust me, needing this is not a matter of if, but when... PhotoRescue is about the best and easiest tool for recovering digital photos I've seen. (Disclosure: IR gets a small commission from sales of the product, but I'd highly recommend the program even if we didn't.) OK, now back to our regularly scheduled review...
Not sure which camera to buy? Let your eyes be the ultimate judge! Visit our Comparometer(tm) to compare images from the Sony Alpha SLT-A35 with those from other cameras you may be considering. The proof is in the pictures, so let your own eyes decide which you like best!
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Note: For details, test results, and analysis of the many tests done with this camera, please click on the tabs at the beginning of the review or below.