Di: Digitally Integrated Design, is a designation Tamron puts on lenses featuring optical systems designed to meet the performance characteristics of digital SLR cameras.
DI Lenses have the following benefits
• Improved Resolution
• Minimized peripheral light fall-off
• Compensation of ghosting and flare
• reduction of chromatic aberations
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.