JPEG Image Size & Quality

Standard Test Scene

The Coolpix 3100 provides five preset image size and quality combinations, to make it easier for the novice user image size and quality are wrapped into a single setting. The lower resolution settings are labelled 'PC' (1024 x 768) and 'TV' (640 x 480) to hint towards the potential use of images at that size.

To give an impression of what some of the combinations of image size and quality produce we have provided samples of each.

  • 3M High (2048 x 1536)
  • 3M Normal (2048 x 1536)
  • 2M Normal (1600 x 1200)
  • PC screen (1024 x 768)
  • TV screen (640 x 480)

Images below are cropped 240 x 100 area of the image magnified 200% (nearest neighbour).

2048 x 1536
936 KB
609 KB

1600 x 1200
383 KB

1024 x 768
178 KB

640 x 480
85 KB

The only image quality setting which didn't exhibit JPEG artifacts was the 3M* (2048 x 1536 Fine JPEG) setting, it delivered relatively clean images but with the extra storage penalty of a 940 KB file. Go further down the size / quality settings and you can clearly see ringing and 'mosquito noise' artifacts surrounding areas of detail, which is a pity because I would guess that some people may shoot this camera in the 1024 x 768 size for email purposes. It would have done no harm to have slightly less compression at these smaller sizes. Additionally I wasn't overly impressed by the lack of a decent interpolation algorithm used to downsample images.

Image Parameters

In 'manual record' mode the Coolpix 3100 provides control over image sharpening, no other image parameters can be adjusted. That said however many cameras at this level offer no control over any image parameters.