A French photographer who runs various experiments for his YouTube channel collaborated with one of his peers in order to create a DIY UV lighting setup to expose what our skin looks like when different, everyday cosmetics are applied.
The three-minute video shows French photographers Mathieu Stern and Pierre-Louis Ferrer assembling ultraviolet light bulbs and a giant UV ring flash. The pair recruited various female subjects to sit in front of the lens.
Stern uses the UV-sensitive camera to reveal how the women initially look under UV lights. He then has his subjects apply a variety of different everyday skincare and cosmetic products to review the effect via UV-cam, showcasing what is not visible to the naked eye. Freckles that were previously faint become much more prominent, whilst sunscreen appears black on the skin. They also test out a clay mask, foundation makeup, and a number of foods.
You can see high-res stills below, as well as watch the video and the behind-the-scenes making-of to see how it was all done.

source: fstoppers.com