Why is it that the brighter the lighting in the studio, the black products produced by SLR?

First of all, do you know how to adjust the brightness of the picture with SLR? . . If you don't know, get to know the three values of ISO shutter speed and aperture, and then take a picture, otherwise you can't operate at all. . . The higher the ISO, the slower the shutter speed and the smaller the aperture value. . Are ways to increase the brightness of the picture, otherwise the darker it is. . Don't use automatic gear when taking pictures in the studio, use M gear, that is, manual gear. After adjusting the value, don't move the value as long as the light remains the same.