Field of View:
The 40mm is a DX lens for DX cameras. It will not work on an full frame camera unless you enjoy heavy vignetting for artistic effect. The view angle is only slightly narrower than the 35mm, so if you are planning to upgrade from the kit lens and have not purchased a 35mm or a 50mm, this may be a good lens to consider. I chose this one because it does everything a prime lens does, but it also has macro capabilities. All-in-one multi-functional.
This lens works as a great general purpose lens because, when used on a cropped sensor camera, this lens mimics natural human vision. That means it will work well for travel photography and street photography. You can also use it for full length portraits and possibly mid length portraits, but it may be to wide for head shots. You would have to get uncomfortably close.
Of course, the whole point of choosing this lens over other cheaper prime lenses is that you can get really close. Super close. 1 to 1 magnification. That is where the macro feature comes in (or “micro” as Nikon calls it). It makes this lens is great for food photography. This lens would probably not be a good choice for studio work on a tripod from far away as it is too wide.
Aperture and Focus:
Maximum aperture is f2.8, but decreases to 3 point something when focused in super close. according to other reviews and test sites, the sweet spot for the sharpest images is between f4 to f8. I have no idea if that’s true. Everything looks pretty sharp to me. Auto-focus is fast and responsive on my camera. I use point focus option for selective focusing when I want to blur out foreground or background elements.
The only drawback is that this is a prime lens, which means manual zooming with your feet. Other than that, this is a great general purpose lens with macro capabilities. If you already own a 35mm or a 50mm, don’t buy this one because it would be redundant. Else, if you are looking to upgrade from you kit lens and you have a DX camera, you may want to get this one for extra sharpness and versatility.
It’s great. I’ve been using it and the pictures are super sharp! Great for travel photography. Great for food photography. Great for product photography, if you’re trying to sell stuff on ebay. Probably not the best lens choice for portraits. It takes great pictures and is in a price range that is accessible to normal people.
The 40mm is the cheapest macro lens available from Nikon at $280. The next one up is the 85mm at $530. The 40mm does cost more than the 35mm, an $80 difference.
Compare tech specs at Nikon.