Tamron SP 45mm f/1.8 Di VC USD review – Image quality

I’m pretty impressed with the quality of images this lens produced. I value wide-aperture sharpness and am pleased to say that although the lens doesn’t perform at its best at f/1.8, it’s still very good and sharpness is more than acceptable. It’s no surprise that resolution is better in the centre by f/4 and that the edges catch up by f/8, before things soften off a little from f/11 to f/16. Throughout the aperture range, though, the lens produces nice sharp images, and at no point did I notice softness that I found unacceptable.

At f/1.8 the characteristic of the lens is rather beautiful

At f/11 it’s a bit more crisp and factual

The benefit of the nine-bladed iris is easily seen in images shot between f/2 and f/4. Highlight orbs are nicely rounded and evenly illuminated, and they remain mostly circular close to the edges of the frame. This is a very pleasant characteristic, especially for those who like to shoot wide open to create a non-distracting backdrop for their subject.

Vignetting seems reasonably well controlled beyond f/2.8, although it is more than noticeable in flatly lit subjects when the lens is wide open. I rather like the effect, but it is a fault nonetheless – though not one that destroys images. More pleasing is the lack of chromatic fringing in images taken at all apertures. When inspected at 100% some cyan/green separation is visible along high-contrast edges, but you do need to look that close to see it. A click of the auto-correction button in Capture One Pro soon makes it disappear. As the iris closes, the fringing slips away and none can be seen when best sharpness is required around f/5.6-8.

The VC proved its worth in low-light situations and, helped by the usability of the f/1.8 aperture, I was able to avoid racking up the ISO as often as I might have done otherwise. However despite the assistance of the USD motor, I didn’t find the AF especially speedy, and have a number of pictures of moving people who have the focus on the back of them, not the front.