Curves are a powerful tool in Photoshop, and can be used to make a variety of edits to your photos. To use curves, first open the Curves dialog box by going to Image > Adjustments > Curves.
In the Curves dialog box, you’ll see a graph with a diagonal line running from the bottom left to the top right. This line represents the tonal range of your image, from shadows to highlights. You can click on this line to create anchor points, which can be used to adjust the tonal values of your image.
To adjust the shadows, midtones, or highlights of your image, click on the corresponding button at the bottom of the dialog box. This will cause a new anchor point to appear on the line. You can then click and drag this point to lighten or darken the corresponding tones in your image.
You can also adjust the overall brightness of your image by clicking on the white point or black point on the line and dragging it up or down.
The Curves tool is a powerful way to make subtle or dramatic changes to your photos. With a little practice, you’ll be able to get great results with this versatile tool!