I am trying to film dental procedures with my iphone 6s plus but the light that I must have to do the procedure is too bright to get a good picture. Is there a setting I can adjust to get a better picture?

I like videography&photography very much even if i am just an amateur, and i haven't taken any relevant classes in this area before. In general, i prefer to use my Iphone to take pictures, and recently i made an attempt to make some videos. Iphone is very convenient , but I really want to make a...