General Tab Sheet
The General tab sheet contains
controls for adjusting the brightness, contrast and other image parameters.
Unlike the controls in the Selective tab sheets, which influence only certain
image areas, the General controls work on the whole image.
The Brighten slider lets you increase or decrease the brightness of the image in EV steps from -3.0 to +3.0. For many images you will only need adjustments between -1.0 and +1.0 though. It doesn't work like the brightness or gamma sliders that are known from many graphics applications. It doesn't cut off shadows or highlights and also doesn't change the contrast.
The Contrast slider does what its name suggests: It adjusts the contrast of the image. Values below zero can make some details more visible, but can create a more grayish look. Values above zero increase contrast and give the image more punch, but may make some shadow details less visible. If you deactivate the check box at the left, the Contrast slider is split up into two sliders, called S-Contrast and H-Contrast, for adjusting the contrast in the shadow and highlight areas independently. If both sliders have the same value, the effect is the same as that of the single Contrast slider.
The Amplify slider is meant to be used in addition to the Brightness and Contrast sliders. It offers further precision for brightness and contrast adjustments for difficult images. It performs a white point adjustment for positive values and a black point adjustment for negative values. Please use with care, because it can easily blow highlights or suppress shadows.
The Color Contrast slider works quite differently from the above mentioned Contrast slider. It uses the color differences in the original color image to increase the contrast of an image. Values above zero make blue areas darker and red and green areas brighter, which is what a traditional Polarizer filter does. On the other hand slider values below zero will make blue areas brighter and red and green areas darker.
The Multigrade and Paper Density sliders simulate the effect that different B/W photo papers had on the traditional B/W photo. The Multigrade slider ranges from -2.0 to +3.0. A value of zero will have no effect on the image, values below zero will make the image appear softer and values above zero will increase the edge contrast. The Paper Density slider controls the roughness of the effect. Higher values will make the effect rougher whereas low values will produce an effect with finer details.