Tamron SP 80-200mm f/2.8 LD (Model 30A) adaptall lens is an absolutely superb optical design which features a three element focus group integrating one low dispersion (LD) element, plus a five element variator group coupled with a three element compensator group. This lens is the ideal portrait lens due to its flexibility in combination to its inherent sharpness and contrast. It is extremely soft in the corners at F/2.8 due to relatively slight off-axis astigmatism and coma. Chromatic aberration and lateral color are extremely slight as well. Corner sharpness equals center sharpness by F/4, producing very sharp images across the entire film plane. Sharpness peaks at F/8 with razor sharp images.