Nikon-fit lenses that are fit for full-frame
Following on from last month’s roundup of DX-format wide-angle lenses, we’re now turning our attention to FX-format ones. Again, we’re not covering fisheyes – sticking to wide-angle lenses with rectilinear optics which, as far as possible, aim to keep distortions to a minimum.
Moving from DX to FX territory, one noticeable difference is that you’re no longer limited to zoom lenses when going wide. There are plenty of 24mm, 28mm and 35mm prime lenses available, all of which are classed as wide-angle lenses. However, these focal lengths are all covered by standard zoom lenses. For this test, we’re therefore concentrating on lenses that deliver shorter focal lengths and an even wider angle of view. Even so, it’s interesting to see how a topquality 24mm prime lens compares with standard zoom lenses at their shortest focal length, so we’re also including the Nikon 24mm f/1.4.
Viewing angles can be measured on the horizontal, vertical and diagonal. Manufacturers most commonly state the diagonal angle, as it’s the biggest. The maximum viewing angle of the Nikon 24-85mm standard zoom lens is 84 degrees. Compared with this, the Nikon 14-24mm, 16-35mm and 18-35mm give maximum viewing angles of 114, 107 and 100 degrees respectively. In each case, a difference of just two millimetres in the focal length of wide lenses has a noticeable effect on angles of view.
Warp factor none…
As well as squeezing more into the frame, wide-angle lenses have the effect of greatly exaggerating perspective. With this in mind, many photographers tend to use wide-angle zoom lenses at or near their shortest focal lengths to maximise their potential. However, doing so is missing a trick. At their mid-range or longer zoom settings, wide-angle lenses typically give much less distortion than when using a standard zoom at the same focal length. For example, the Nikon 24-85mm gives pronounced barrel distortion at its shortest focal length, equivalent to a score of -4.07 in our lab tests. By comparison, at the same 24mm focal length, the Nikon 14-24mm gives much less distortion, equating to a score of -0.63, and the Nikon 16-35mm gives barely any at all, scoring just -0.04.
This gives wide-angle zoom lenses a distinct advantage over standard zooms at a 24mm focal length for architectural photography and other scenarios in which unwanted distortions can be noticeable. The same can’t be said for most wide-angle prime lenses but, again, barrel distortion is quite restrained in the Sigma 20mm and Nikon 24mm lenses on test. It’s helped by the fact that they both have a longer focal length than is available at the short end of all the zoom lenses in the group. The generous viewing angle of the Samyang 14mm prime lens results in a similar amount of barrel distortion to most zoom lenses at the short end of their zoom ranges.