Nikon D3X vs Sony Alpha 850 – Noise, resolution and sensitivity
Image: Both these raw images were processed in Adobe Camera Raw, with no noise reduction applied, but they were sharpened individually. Both show the same amount of detail, but noise is better controlled in the image taken by the D3X
Image quality should be the ‘meat and potatoes’ of any photographer’s camera-purchasing decision. With more than 24 million pixels, both the Nikon D3x and Sony Alpha 850 are capable of resolving a lot of detail.
At ISO 100, both cameras reach an impressive 30 on our resolution chart.However, as soon as the sensitivity increases, the differences between the processing systems of the two cameras becomes apparent.
Although our noise test shows that the Alpha 850 has a high percentage of noise in the red channel, the green, blue and luminace channels actually show slightly less noise than the D3X.
Both raw and JPEG files from the Nikon D3x are clear at ISO 400 and ISO 800, but chroma noise has started to creep into images produced by the Alpha 850.
The Sony camera also suffers from luminance noise and a speckled effect is present in raw files, while smudging, which is caused by noise reduction, has affected JPEG images.
In contrast, the level of noise is far better controlled in JPEG files produced by the Nikon D3X, and it is easily reduced in raw images.
Images from the D3X at the maximum ISO 6400 sensitivity have a soft, granular texture, whereas the Alpha 850 images have a clumpier, blotchy texture. Nikon has designated the ISO 3200 and ISO 6400 settings as the extended Hi-1 and Hi-2 sensitivities, meaning they are not recommended for regular use but only if and when needed. I would recommend Alpha 850 owners adopt the same approach.
Image: In this JPEG image taken at ISO 6400, the Nikon D3X shows little in the way of chroma noise. However, it does take on a rather smudged appearance
Image: The Sony Alpha 850 JPEG image shows patches of coloured chroma noise at ISO 6400
