Select a test from the dropdown list of "tone".

Contrast means the distinction between bright area and dark area. When increasing the contrast, the bright area becomes brighter and the dark area becomes darker, i.e. high contrast.

This is the reference to judge the brightness when adjusting the contrast. Upper from the contrast center is considered as bright, and lower is considered as dark. In other words, this reference decides the point where the brightness level is not changed when adjusting the contrast. When setting the contrast center smaller, you feel the tone of an image becomes lighter. This is because the contrast is increased based on the dark area, and causes the dark area to turn smaller and the bright area larger. On the contrary, when setting the contrast center bigger, you feel that the tone of the image becomes darker. Increasing the contrast means compressing the gray scale of bright area and dark area and expanding the gray scale around the contrast center. Therefore, if a target object is dark, set the contrast center smaller, and if it is bright, set the contrast center bigger to get the ideal tone. The contrast center is displayed on the "Histogram." When you move the cursor to the position on the photo currently displayed in the preview screen while histogram is displayed, the brightness of R, G, and B on that point is displayed. With this function, make adjustments, looking the brightness distribution on the area you want to add contrast, and you can find the appropriate level relatively easily.

Gamma is brightness adjustment. As the gamma is larger, the overall brightness becomes higher, and vice versa. You may think it is the same as exposure bias operation, however, they are not the same thing. With the exposure bias, the brightness is adjusted without changing the ratio of bright area and dark area. On the contrary, with gamma, the ratio is changed. When increasing the gamma value, the bright area is compressed, and the dark area is expanded. When decreasing the gamma value, the dark area is compressed and the bright area is expanded. Therefore, in this software, this operation is considered as tone-change-operation and classified as 'Tone Adjustment' since it changes tone.

Black level controls clear expression of the dark area. You can specify the level of black with this function. When increasing this parameter, the color black becomes deeper black. This function works effectively when a picture is taken against the sun and the image becomes unimpressive, or when a landscape image becomes grayish, influenced by irregular reflection of air.