Why is the background of the products I took with my camera different?

If it is chromatic aberration, it is white balance! However, what you said is the problem of light and shade, so it is the cause of photometry. In the automatic mode, the camera automatically gives the exposure value according to the subject, which makes the exposure of the subject accurate. Simply put, the lighter the subject color, the smaller the exposure and the darker the surroundings. The darker the subject color, the greater the exposure and the brighter the surrounding environment. If the exposure is not enough, the black subject may be dead and dark. There are three solutions: 1 manually set the aperture shutter sensitivity to fix the exposure value (if there is a manual mode); 2 Increase or decrease exposure through exposure compensation (common cameras have it); 3 (If the camera has the function of selecting metering points) Select the same color object for metering (If you have an iphone or a better Android phone, you can click on the picture on the screen in the shooting interface for focusing metering, and the brightness of different photos will be different when clicking.