A few scanning tips



These images were contributed by Ed Hamrick, the author of VueScan.   VueScan 7.2.4 was used with a Nikon LS-30 scanner with an infrared channel. The color negative is Fuji 800 film, using VueScan's Generic Negative film type.

Note that there are two ways to increase the brightness of the image, including the darker areas too. Increasing Brightness, or increasing the white point percentage (which moves the white point to the left) lightens the image, and also increases image contrast.

All-default settings. Note the long horizontal scratch across the top.

Infrared Cleaning filter turned on, to remove the scratch. There isn't any color shift between scanning with and without the cleaning filter in VueScan.

Cleaning plus 15% white point.

Moving the white point to increase the intensity in the dark area clips detail (loses detail) in the sky area (and looks like the print of this negative) The VueScan default is 1%.

Cleaning plus Brightness 1.5 (and default 1% white point).

Increasing Brightness increases the intensity in the midrange and dark areas without losing detail in the sky area.

In VueScan, Brightness is a multiplier that modifies Gamma, which boosts the midrange tones (Brightness 1.5 and Gamma 2.2 equals Brightness = 1 and Gamma 1.5 x 2.2 = 3.3). VueScan Brightness is the same as the MidPoint in most histogram tools.

This trade-off between white point and brightness can be used to great effect when scanning negatives because there is a wider range of intensities captured with color negative film. Slide film and prints don't have as much of an intensity range, so using the default options in VueScan are usually sufficient.

The white point % setting affects the image intensity because the specified percentage of the pixels in the image is clipped, at the right of the white point. The larger the white point % setting, the more highlights are clipped (and the 15% here is a LOT). This clipping limits the original range for the purpose of creating greater contrast. It also increases overall image intensity.

Copyright © 2000-2010 by Wayne Fulton - All rights are reserved.

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