D 3 100 photo The picture taken on a white background is a gray background.

I looked at your picture and found two problems.

The aperture is a bit large, the depth of field is not enough, and the product details are not fully displayed. It is recommended to close the aperture by 2 pieces.

Secondly, the problem of background gray is normal. The metering system of the camera is calculated according to 18% of the reflected light. So when you look at something white, when the camera shoots it, it is gray. So if you want a white background, either add lights to the background or increase the exposure compensation of 1-2.

There is a principle in filming called "white plus black minus". However, the main body in your picture is a product and it is black, so in order to show the details of the product, you should lower the exposure compensation by 0.3-0.7, and replace the evaluation side light or matrix side light with the central key side light. To make the background whiter, you can add a light source.