Digitally Integrated Design (Di) is a designation Tamron puts on lenses featuring optical systems designed to meet the performance characteristics of digital SLR cameras.Tamron introduces a new version of the famous 90mm macro lens for film and digital photography. Tamron's 90mm macro lens, often referred to as the portrait macro and loved by photographers all over the world, is now reborn as a Di lens that is perfect for use with both film and digital cameras. more info