Tamron SP AF 90mm f/2.8 Di Macro

Tamron SP AF 90mm f/2.8 Di Macro

As Tamron's macro has a focal length of 90mm rather than 100mm or 105mm, the lens has to be slightly closer than would otherwise be the case to record a true macro (1:1) image. That said, Tamron also offers a 180mm macro for times where a greater camera-to-subject distance is more appropriate. Although its AF mechanism is rather noisy, it is reasonably quick and very reliable thanks to a near-total absence of hunting. Switching from AF to manual mode is as simple as pulling the focusing ring backwards for Nikon and Canon users, but Minolta/Sony and Pentax users must also reset their camera bodies accordingly. The focused distance is shown in a window on top of the lens together with the reproduction ratio, which is hard to read. A white line is drawn between 0.4m and 0.45m, indicating that the focus limiter can restrict focusing to the closer side of 0.4m or the more distant side of 0.45m, but the 5cm between can only be accessed when the focus limiter is deactivated. This is likely to be immaterial in most cases. Conventional MTF testing revealed a significant weakness at f/2.8 but a solid range of results from f/4 to f/11; even at f/16 the resolution remained above the critical 0.25 cycles-per-pixel level. Improvised macro-MTF testing revealed a similar pattern, with particularly good results being recorded from f/4 to f/8.