B-Tuned lenses are experimental Bespoke tuned lenses. The set gained popularity which is why it became dubbed B-Tuned lenses. These lenses offer multi-coated element with no edge coating, performing in similarly to the S-tuned lenses in terms of light management and flare control. Due to the selective uncoating, the lenses will have a slightly more washed out look to them in direct light. Please note that the ghost flares will be a light green/blue, more translucent elemental signature than standard S-tuned lenses.