Small, affordable and with a minimum focus of 16.3cm, Nikon’s 40mm f/2.8 micro lens may be suitable for more than just macro images. Richard Sibley finds out what it can do
The first things that impressed me about the Nikkor 40mm f/2.8 lens were the rich colours and good level of contrast that it produces. These can really help to accentuate small details. What made this level of contrast even more evident was when I took the same image with a 55mm f/3.5 Micro Nikkor optic, dating from the mid-1960s.
This lens has a lower level of contrast, and when images are taken against a bright-white background they look very dull and desaturated. With anti-flare coatings, the bright white background was no problem for the 40mm f/2.8 lens and the images have a good level of contrast.
What is interesting is that this level of contrast is consistent throughout the aperture range of the lens on test. There is a slight drop in sharpness at f/2.8, but between f/4 and f/11 all images have about the same level of detail. At f/16 and f/22 there is a noticeable drop in sharpness and resolution, according to our test-chart results. In real-life examples, although the slight loss of sharpness is noticeable by comparison, in isolation images are still perfectly acceptable.
Image: The 40mm f/2.8 lens has only slight distortion and produces images with a good level of contrast
Generally, the 40mm f/2.8 lens performance is much like that of the AF-S Nikkor 50mm f/1.8G lens that we tested in AP 23 July. Similar optical coatings have been used on both lenses, and although two more optical elements are used in the 40mm f/2.8 lens, image sharpness in both lenses is almost identical.
There is some optical distortion produced by the lens, namely a slight pincushion effect. This is obviously much more noticeable at the closest focus distance, and those wishing to use the lens for photographing printed material, such as stamps, should consider this before shooting. Leave a little space around the subject to allow for software correction and subsequent cropping.
Red/cyan chromatic aberration is visible in some situations. The in-camera processing should remove, or at least reduce, any chromatic aberrations in JPEG images, but those editing raw files will have to perform the task manually. I found that it was very easy to remove the chromatic aberration using Adobe Camera Raw, with only a slight shift needed.
Vignetting is also present when shooting, although in most situations it will only ever be really noticeable when shooting at f/2.8. Once again, it can be corrected by switching on the in-camera vignetting control, or it can be easily removed from raw files using editing software.