ISO Sensitivity / Noise levels (contd.)

Noise reduction and fine detail

Noise reduction systems, whether they be in-camera or in image manipulation programs, don't just reduce noise. Generally, detail suffers too, especially towards the higher end of the ISO scale where noise is at its highest. The Nikon D3000's applies noise reduction to high ISO images by default, but the intensity of the processing can be increased by switching noise reduction to 'on' in the shooting menu.

With this in mind, the best option for photographers that want more control over noise reduction is to shoot in NEF mode and convert the files in Capture NX2 or a third-party converter such as Adobe's Camera Raw for Photoshop/Lightroom. View NX, which is bundled with the D3000, does not offer a noise-reduction control. In fact, the approach that View NX takes to high ISO noise reduction is to essentially mimic the appearance of JPEGs processed in-camera at whichever noise reduction setting is used. When shooting normal photographic subjects, apart from a slight increase in sharpness (and a corresponding increase in 'grittiness') there isn't an enormous difference in terms of critical detail reproduction between JPEGs straight from the camera and NEF files processed in View NX.

To check the effect of noise and noise reduction on low contrast detail we shoot our new studio setup at various ISO and noise reduction settings (where available), then crop an area that's challenging to any camera. The very fine detail in the feathers will help to better judge the effect of noise reduction on fine detail.

Raw vs in- camera JPEG noise reduction low contrast detail comparison

At its default settings, Adobe Camera Raw does a good job of removing the worst of the chroma noise from the D3000's high ISO NEF files, and also delivers slightly better detail in both low and high contrast areas than the camera's JPEG engine. It is clear from looking at these images why Nikon reserves ISO 3200 as an 'emergency' extension setting - the increase in noise from ISO 1600 to 3200 is quite sudden, and detail drops dramatically as a result of in-camera noise reduction in JPEG images. This decrease in resolution is most pronounced when noise reduction is turned on, at which point the D3000 becomes much more aggressive in its treatment of noise at ISO settings of 800 and above.

  NEF (ACR NR Off) NEF (ACR default NR) JPEG NR off (default) JPEG NR on
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600

Hi 1 (ISO 3200)