Sony DSLR-A580 High ISO NR
Sony A580 High ISO Noise Reduction
The Sony A580 offers only two high ISO noise reduction settings: Auto and Weak, with Auto being the default. We've also included crops from the new Multi-frame Noise Reduction mode, which shoots a burst of six images with a single press of the shutter button and combines them in-camera to average out a lot of noise.
See for yourself how the noise reduction works under daylight-balanced lighting at high ISOs. Click on any of the crops below to see the corresponding full-sized image.
The above crops show the effects of the Sony A580's two high ISO noise reduction settings, plus Multi-frame Noise Reduction under our studio HMI lighting we use to simulate daylight. As you can see, the "Weak" setting does result in more chroma noise than the Auto, but it also smudges detail in the red leaf fabric at higher ISOs more than Auto. (You can really see a difference at ISO 1,600 and above.) It would have been nice if Sony gave us more flexibility in NR settings or at least a truly "Weak" setting.
The new Multi-frame Noise Reduction mode takes a burst of 6 shots and combines them to average out noise. This mode is similar to Hand-held Twilight, but gives you control over ISO and exposure mode (PASM). It produces some very clean, detailed images and also extends the available ISO settings to 25,600, but still requires the use of a tripod at slower shutter speeds, so similar results can be obtained by simply shooting at a lower ISO with longer exposures if you're already using a tripod.
How do the Sony A580's JPEGs compare to state-of-the-art APS-C models with similar resolution at high ISOs? See the following table which compares at the default noise reduction setting.
All four cameras in this group show similar levels of noise at ISO 800 with the Canon 60D and Sony A580 showing a touch less, but both are starting to blur tone-on-tone detail in the red leaf fabric more than the others. At higher ISOs, the Nikon D7000 starts to pull away from the pack in terms of low contrast detail in reds, with the others applying stronger chroma noise reduction. However, the K-5 and 60D both do a slightly better job at keeping higher-contrast detail more clearly defined. It's also no surprise that the 18-megapxel Canon 60D outresolves the other three which all have 16-megapixel sensors.
In general, the Sony A580 applies stronger default noise reduction than the others. Still, the Sony A580's performance is competitive compared to its peers, but we do wish it offered more control over noise reduction. The good news is you can always shoot RAW for the ultimate control over noise reduction, as the Sony A580 does not apply NR to its RAW files.