We test the Nikon D200 digital SLR at night for long exposure noise
The following images were shot with exposures of 30 seconds and varying aperture, to give the correct exposure value.
The D200 has two types of noise removal: Long Exposure and High ISO. High ISO noise reduction kicks in at 400ISO and above.
The RAW files for these images are available on the special digital camera section of the site for download so that you can examine the images yourself.
These exposures were made in Shutter-priority mode with a starting exposure
(100ISO) of 30 second and f13. They were shot with the Nikon
18-70mm, f3.5-4.5G ED-IF AF-S DX Zoom Nikkor lens, at a focal length of 70mm.
100ISO all noise reduction off
100ISO Long Exposure NR on, High ISO NR off
The addition of long exposure NR softens the image very slightly but also reduces some very subtle noise in the sky areas.
For the following images we left High ISO noise reduction on but varied the long exposure form.
400ISO, Long Expsosure NR off
400ISO, Long Exposure NR on
Both images are soft (from the High ISO NR), but Long Exposure NR does kick back the noise without softening the image further
1600ISO, NR off
1600ISO, NR on
Here the use of both NR technologies seems to have actually increased the noise, although the results are still very good for such a long exposure.