# Negative Surface Reflectance

I am using Landsat Surface Reflectance Level-2 images. I have to convert the DNs to reflectance values. When I apply the formula provided in the Landsat8 User Handbook :

in the metadata file, Reflectance_MULT_Band = 2.0000E-05 and Reflectance_Add_Band= 0.1 The problem is I am getting negative values even after correction for the solar elevation angle.