In the eye of the beholder?

I was surprised and a little puzzled on reading your usually excellent guidance in the portrait lenses test ( N-Photo 69). It was not so much that your figures seemed at odds with the results produced by

photozone.de, DxO and Ken Rockwell, who rated the Sigma 85mm f/1.4 very highly, with the Nikon 85mm f/1.4 not far behind; obviously samples vary and methods of testing are different.

But I did not understand how the Tamron 85mm f/1.8 emerged as the winner, when your own results seemed clearly to contradict this. I would have thought that, in portraiture, what you need is maximum sharpness and contrast, bokeh being not visible with a backdrop in a studio and significant only in outdoor pictures. Similarly, vignetting is fairly unimportant in portraiture, and both that and barrel/ pincushion distortion can be offset in Photoshop as well as in DxO.

If that is so, then on your charts the best 85mm lens looks to be the Nikon 85mm f/1.4, which only got four ‘blobs’ for performance (and was considered “outdated”); half a blob behind the Tamron, which seemed to have noticeably inferior sharpness. The runner up, the Sigma 85mm f/1.4, was worse still, yet was said to have “beautiful image quality”. Perhaps you can help by explaining the weighting you apply to different characteristics in reaching your final decision? Michael Becket, via email Lab test results never really tell the whole story and, for portraiture, the pictorial quality of defocused areas in a scene can be more important than whether the lens is sharp enough to reveal every blemish and wrinkle. We felt that the Tamron delivered the best performance and handling, as well as better value for money.