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Shadow noise

The latest generation of sensor (as seen in the Sony A580, Nikon D7000 and Pentax K-5), has gained a great deal of dynamic range at low ISOs with a new design that offers much lower (sensor/electronics-derived) read noise. This means that much of the detail captured in shadow regions can be pulled back into images without bringing too much noise at the same time, giving tremendous latitude in post-processing. The Sony SLT-35's sensor is closely related to the sensors in the cameras mentioned above but has, according to Sony, been modified for energy saving and heat resistance. Despite these modifications the difference to the cameras using the older version of the sensor is marginal.

In the example below we've illustrated this by pulling up the shadows using Adobe Camera Raw with all noise reduction turned off, to give the closest possible representation of the sensors' inherent capabilities. The shadow noise on the A35 is a touch higher than on the Sony DSLR-A580 but lower than on cameras with more conventional sensors.

Sony SLT-A35 - ACR+3.0EV Sony DSLR-A580 - ACR+3.0EV
100% crop 100% crop

Raw shooting

The Sony SLT-A35 comes with the same software bundle as the SLT-A55 and most recent Sony SLT/DSLR models. It includes the cataloging and browsing application Picture Motion Browser (Windows), the browsing and workflow application Image Data Lightbox (Windows / Mac) and the RAW converter Image Data Converter (Windows / Mac). You can read more about the software package on the RAW page of our A55-review. The samples below have been converted using Adobe ACR 6.5 beta.

On the left is the out-of-camera jpeg, on the right hand side is the same image with custom sharpening applied during RAW conversion in Adobe ACR 6.5 beta (amount 32, radius 1.0, detail 67, masking 0). As you can see there is a marginal amount of additional fine detail in the converted image but you'd struggle to spot a difference at a magnification smaller than 100%.

As you can see in the sample shot above converting the A35 output in ACR does not get you an awful lot of additional detail. However, RAW conversion is of course about much more than only sharpening. It allows you to take control over white balance and noise reduction and, to a degree, even exposure. This is demonstrated in the sample image below.

The A35's metering system and Auto White Balance somewhat struggled with this ISO 100 shot in the shadow. The shot is underexposed and has a strong blue cast. However, the image could be saved using a RAW converter. We lifted the exposure by 1.15 EV and modified the color temperature to correct the cast. The resulting jpeg is correctly exposed with neutral colors. Despite the digital exposure compensation shadow noise is well under control.

Overall Image Quality / Specifics

The Sony SLT-A35's sensor and imaging pipeline are closely related to the first SLT camera that was announced in August 2010 - the SLT-A55. It's therefore not a surprise that the image output from both cameras is very close. That said there is a slight difference in noise performance. The A35's base noise levels are slightly higher than on the A55. When shooting JPEG this is partly compensated for by a slightly more heavy-handed noise reduction which results in some additonal loss of fine detail. That said, the difference is really only visible at ISO 3200 and higher.

Other than that, the differences to the A55 are marginal and you'd struggle to spot any of them at low ISOs. Like the A55 the A35 has a very wide dynamic range in JPEG mode of almost 9EV which means that assuming metering is accurate, highlight clipping is not a problem in all but the most challenging of scenes. Metering, AF and Auto WB work reliably - with only a few exceptions all our various hundred sample pictures were correctly exposed, in focus and with good white balance.

There is not a massive difference in image quality between out-of-camera JPEGs and converted RAW files but those who want the best RAW conversion can squeeze some extra detail out of their image files, especially in low contrast areas of the image. It also gives you better control over white balance, sharpening, noise reduction and some other shooting parameters.

We would expect ghosting effects to be visible around punctual light sources in night shots. However, despite our best efforts to provoke the effect, we could not spot any obvious signs of ghosting in our SLT-A35 samples.

Due to their unique design, the cameras in Sony's SLT-series can, at least in theory, be prone to so-called 'ghosting'. This effect is caused by the presence of the semi-transmissive mirror in the camera's light path. It takes the form of a vertically displaced ghost image around highlight areas, and is caused by a tiny portion of the light which passes through the mirror being reflected off the inner surface of the mirror and back onto the sensor. While we could find some signs of ghosting in our SLT-A55 review, on the A35 we struggled to spot the effect in any of our several hundred sample shots, even in urban night shots, where ghosting tends to be most visible around punctual light sources.

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