Noise, resolution and sensitivity
Image: Even in overcast light, resolution is good and colours are vibrant with natural tones
As mentioned before, the sensitivity range of the D3100 has been increased from the D3000 and now stands at ISO 100-3200. This can be further extended to ISO 6400 (Hi1) and 12,800 (Hi2), which boosts low-light capabilities and is impressive for a camera in this class. Unlike some other Nikon SLRs, the ISO 100 is not an expanded Low ISO but it is where the ISO range begins, which is impressive.
An increase in resolution from 10.2 million pixels in the D3000 to 14.2 million pixels in the D3100 is a substantial improvement, and it is no surprise that the new camera resolves more detail than the D3000. The amount of detail resolved is respectable, reaching 24 on our charts, although for a 14.2-million-pixel sensor I would expect slightly more. What is good, though, is that the resolution of detail is consistent all the way through from ISO 100 to the highest sensitivity of ISO 12,800, with only a slight drop off to 20 on our charts. Unedited raw files are able to resolve slightly more detail.
Image: There is good detail in shadow and highlight areas in this scene of low light. Noise levels are respectable, too
It would hardly be surprising that high levels of noise are present at such ISO settings. However, I am pleased at how the D3100 coped with noise in my images. Using the noise reduction makes lines a little sharper and punchier, but overall pixels in my images became slightly more smudged as the ISO sensitivity was raised.
Resolution charts: These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using a Nikon 18-55mm f/3.5 kit lens at 50mm. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.
