This close-up attachment can be used with most EF lenses & the Canon PowerShot Pro90 IS to provide a shorter minimum focusing distance with no loss of light. Changes closest focusing distance from infinity to 500mm (approx. 19.7") from front of lens. The "D" series incorporates double-element achromatic design for maximum optical performance. The 500D works best with telephoto lenses from 70-300mm, manual focusing is recommended.