How does Nikon D90 match the photo studio to shoot black clothes?

1. Turn down the Iso, set the lamps, and first set the aperture, preferably between 4 and 8 (usually this is the best resolution of the lens). 2. Stick a piece of white paper (white card) on the clothes, fill the viewfinder and do a manual white balance sampling. 3. Put the back of hand (18 degree gray card) on the clothes, focus on exposure, and lock exposure value. Complete the adjustment. When the light changes, please do it once from step 2.