Color negative film is able to capture a much wider range of intensities than slide film, and this can create a problem when scanning negative film.
Slide film maps a density range of 0:2.7 to an intensity range of 1:500, but negative film maps a smaller density range of 0:2.4 to a larger intensity range of 1:4000.
Imagine taking a picture of a typical outdoor scene with a bright blue sky with fluffy clouds along with a person standing in the shade under a tree. Further, imagine taking this picture with both slide film and negative film.
When taking this picture with slide film, the photographer has to set the exposure to either capture the details of the sky and clouds, or set the exposure to capture the details of the person standing in the shade under the tree. Once the picture is taken of one of the two intensity ranges, there’s no way to get back the other intensity range after developing the film. However, when taking this picture with an automatic camera using negative film, the camera will usually set the exposure so that both the details in the clouds and in the shadows are captured.
The decision of whether to capture the intensity range of the clouds or the person in the shadows is made by the photographer when using slide film, but it’s usually made by a computer in the film minilab when printing the negative. Most minilabs will print this type of scene with details in the shadows and the sky clipped to white without any cloud or sky detail.
One way to solve this problem is to manipulate the brightness of the image using the Color | Brightness or Color | White point (%) option to manipulate the negative image so that both the bright and dark parts of the image show detail when scanned.