Saturday, March 19, 2011

Nikon AF Nikkor 50mm F1.8D Lens Review (FX)

The Nikon AF Nikkor 50mm F1.8D

Introduction:
Nikon has been making 50mm F mount lenses for just over 50 years, so they've had a long time to perfect the design of these commonly called, standard lenses. The AF Nikkor 50mm F1.8D is the low cost version of the three 50mm lenses that Nikon produces (at the time this review was written), with the others being the AF Nikkor 50mm F1.4D and finally the significantly more expensive AF-S Nikkor 50mm F1.4G. The design of the 50mm F1.8 goes back to the 1980's with the introduction of the original AF Nikkor 50mm F1.8, which like most of the first generation AF lenses had a very narrow plastic manual focusing ring. The 50mm F1.8 has been revised several times, first of which is considered the 50mm F1.8 "N", which has a similar design to the first one, but added a broader rubberized manual focusing ring. The 50mm F1.8 and 50mm F1.8 "N" use a slightly higher quality plastic than the modern "D" lens, and was similar in construction to that of the 24 F2.8 and 35mm F2. The 50mm F1.8D was released in February 2002, and introduced support for distance information and full matrix metering on modern Nikon SLRs and DSLRs.


Build and Mechanical Quality:
The AF 50mm F1.8D body is made of seemingly low quality plastic, which doesn't seem overly reassuring when you pick it up the first time. Considering that this is one of the cheapest SLR lens that Nikon has ever made, you cannot expect much though. Don't be fooled by the cheap feel of the lens, in some ways the flexible plastic is a plus for this little lens. I say that because this is the only lens that I've ever dropped, on a hard rocky surface, and yet it doesn't even have a scratch on it! Unlike cheap DX kit lenses the 50mm F1.8D features a metal lens mount, so you don't have to worry about it breaking off the camera if you hold the combination by the lens.

The manual focusing ring on the lens seems a little stiff, which makes precise manual focusing difficult, but that seems to be the case with most low cost AF-D lenses. If you are going to do a lot of manual focusing considering picking up a 50mm F1.8 AI-S or Series E, both of which are much better for manual focusing.


Auto Focus Speed and Accuracy:
The AF 50mm F1.8D uses a screw driven motor to auto focus, so lower end DSLRs such as the D40(x), D60, D3000, D3100 and D5000 cannot auto focus with this lens. All current Nikon FX bodies have a built in focusing motor, so you will not have a problem using this lens on the D700, D3, D3s or D3x. Auto focus speed on the D700 is almost instantaneous, and focus accuracy seems to be good overall. Since the camera focus motor drives the lens when auto focusing there will be some noise while focusing, but it is one of the quieter lenses of this type.


Image Quality:
Overall the 50mm F1.8D can produce sharp images, but you do need to be aware of a few characteristics of this lens. First of all the lens is not very sharp wide open at F1.8, in fact my copy is not sharp till around F2.8 on an FX body. Another well known characteristic of the 50mm F1.8 is that bokeh is not overly pleasing in bright areas when wide open. The reason for this is the use of straight, rather than curved aperture blades that higher end 50mm lenses tend to use. Vignetting is almost unnoticeable in the field with this lens on an FX body, but there is some when shooting with the lens wide open.

Considering these negative points, one might wonder why this lens would be very useful, but it isn't all bad news when it comes to the 50mm F1.8D. The good news is that at F2.8 or stopped down more the lens produces sharp images. Contrast is lower than higher end lenses, but considering the age of the design (first introduced in 1986) it isn't bad. The lens is sharp right through to F16 on an FX camera, at F22 diffraction becomes an issue and sharpness drops off.

Image Samples:
These are sample images, all taken with the 50mm F1.8D mounted on a Nikon D700.

Click samples for larger image

 50mm @ F16

50mm @F5.6

50mm @F8

50mm @F2.8

50mm @F2.8 (Harsh bokeh seen in bright areas in this image)

Comments and Final Thoughts:
Unless you want to have an F1.4 50mm lens there are not very many reasons for a FX shooter to avoid the 50mm F1.8D. In fact the only reasons I can think of is that you don't shoot in low light very often, or that you don't like the 50mm focal length. As noted earlier the lens does need to be stopped down a bit (F2.8 or more) to get the best results, but overall sharpness is very good. Bokeh is a little nasty looking in bright areas of the frame at F1.8, and stopping the aperture down doesn't help a lot, but overall out of focus areas are okay.

Pros:
- Cheapest Nikon lens on the market today
- Fast and accurate auto focus on FX cameras
- Good for shooting in low light
- Sharp from F2.8-F16 on FX cameras
- small and light weight

Cons:
- Low quality plastic construction means it isn't overly tough
- Harsh bokeh (out of focus area) in bright areas of the frame
- A little soft at F1.8, avoid shooting wide open