UV cameras should not be used to provide accuracy in verifying or comparing the SPF potency of a sunscreen. They are especially error-prone for tinted sunscreens because of the various components of the physical sunscreen blockers (zinc oxide, titanium dioxide), chemical sunscreen components, and tints that provide desired color tones (formulations contain different amounts of various iron oxides which are of different colors). Some of these components at various concentrations absorb the UV light while some reflect it, making the camera appearance very inconsistent among the different combinations of ingredients to give the desired tint.
These UV cameras can be used to determine if the user has applied a sunscreen, and the areas missed. However, home UV systems may be quite inaccurate in general and of varying quality and accuracy.
Even though this topic is now trending on TikTok, TikTok postings point out the errors of using this method to assess sun protection and cannot compare products.