Who Needs VR?
19 Jul 2008
Professional photographers need a good zoom lens. Artists do not. The best lens in terms of resolution, contrast and image quality is a single focal length prime lens. A zoom cannot compare because it is, by its very nature, a compromise. A zoom represents a futile effort to be all things to all people at all times.
Historically the major disadvantage of zoom lenses over prime lenses, purely in terms of advertisable features, was speed. Most zoom lenses had maximum aperatures of f/3.5 or 4.5. A few had a variable maximum aperature of f/2.8 to 3.8 or 4. They were therefore unsuitable to anyone who needed a lens for low light work where prime lenses reigned supreme.
The latest marketing gizmo devised to attack this inequality is VR or IS technology ("vibration reduction" or "image stabilization"). This technology makes it possible to hand-hold the camera at speeds two or three stops lower than previously possible. Jolly good.
There are several reasons why I have chosen not to partake in this latest fad. First of all, lenses have enough moving parts without this excess technology. I see no point in purchasing a lens which is mechanically more complicated than my camera. The more moving parts any mechanism has, the less reliable it is.
Second, I don't need a zoom lens. I am not a professional photographer. When I see something worth photographing I reach into my bag and choose the proper lens. It ain't that hard.
Third, VR lenses offer no advantage in terms of speed over a prime lens. Do the math. Most of the VR lenses marketed for Nikon cameras have variable maximum aperatures of f/4 to 5.6. If the VR technology gives two stops of additional hand-holdability, then the VR zoom now has an equivalent of f/2 to 2.8. Every prime lens in my bag has a maximum aperature of f/2.8 or better.
Fourth, VR lenses are all zooms and are therefore optically inferior to prime lenses. This is particularly true when shooting digital. Remember that Nikon DSLRs have a 1.5 crop factor due to the size of the image sensor. When using any lens designed for film cameras this means the digital sensor is only reading the central image area of the lens which is opitally the best part of any lens. All lenses suffer some light falloff and degradation in resolution toward the corners. This problem is eliminated when using a prime Nikkor on a DSLR.
Of course if you have a D40, D40x or D60 you can't autofocus with prime Nikkors because these lenses have no motors. They rely on the motor in the camera which the aforementioned models lack. This means the prime Nikkors suffer a slight disadvantage in terms of af speed which may be important if you are shooting sports or if you're an imbedded wartime correspondent. For the rest of us the advantage of fewer moving parts is well worth the absence of a lens-contained motor.
Finally there is the issue of price. You can find used prime Nikkors on ebay for about half what they sell for new, particularly if you buy one of the older non-D versions. The newer "D" versions communicate distance to the camera. Experts disagree over whether this is really any advantage in the real world.
The 35mm f/2 makes a great standard lens for a DSLR. The 50 f/1.8 is one of the sharpest lenses ever made by anyone. On a film camera it's an awesome standard lens. On a DSLR it's a great portrait lens.
Oh yeah and if you have one of the Nikon DSLRs that don't have their own autofocus motors, get rid of it. If you really need the megapixels get a D80. Otherwise you're just as well served with a used D50 or D70.