"Tamron Di-II lenses are engineered expressly for digital SLR cameras with image sensors commonly referred to as APS-C, measuring approximately 24mm x 16mm. Rendering an ideal image circle for APS-C sensors, Di-II lenses also include properties to optimize digital imaging performance. Rely on Tamron Di lenses for use with DSLRs featuring larger full frame (36mm x 24mm) sensors or 35mm film SLRs. Tamron Di lenses are performance optimized for digital SLR cameras and usable with DSLRs featuring sensors commonly referred to as APS-C, measuring approximately 24mm x 16mm, as well as larger full frame (36mm x 24mm) sensors and 35mm film SLRs. Tamron 60TH ANNIVERSARY MODEL 18-270MM Di II VC PZD - THE WORLD'S LIGHTEST, SMALLEST 15x ZOOM, WITH TAMRON'S FIRST PZD (PIEZO DRIVE) AF SYSTEM A light, compact, ultra-high-power 15x zoom lens with PZD (Piezo Drive) the first Piezoelectric internal autofocus motor by Tamron exclusively for digital SLR cameras with APS-C sized sensors. The acclaimed Tamron 18-270mm VC ultra zoom for APS-C format DSLRs has reached an astonishing new level of compactness, performance, and speed with the addition of PZD (Piezo Drive), an innovative ultrasonic autofocus motor based on an advanced piezoelectric design. The result is a lens that's considerably lighter, and noticeably shorter and slimmer (filter diameter: 62mm) than any previous lens in its class, and provides faster, quieter auto-focusing. Signature"