Sometimes You Have to Open Up Wide for Pictures That Say "Aaaahh"
Raise your hand if this ever happened to you. You took a picture of your sweetie-pie at the park. When you looked through the camera's viewfinder, your sweetie-pie's eyes were nice and sharp, along with a bit of her hair and sweater. The shot looked really good. Then you get the pictures back and lo and behold there are tree branches coming out of sweetie-pie's head, a Mr. Softy truck seems to be parked on her shoulder, and the guy in the truck is about to stick a cola float in her ear.
The problem is that you were viewing the image at the lens' widest aperture, but your lens was set to f16. This, by the way, is why they created depth-of-field preview buttons. And now you know why you should use them. Truth is most people fail to take advantage of the imaging qualities of shooting with wider apertures. If anything, selective focus is a powerful imaging technique that is overlooked by many shooters. It's terrific to be able to get everything in focus, but you don't always want everything in focus.
While we often associate ultra-fast glass with low-light shooting, there's actually no reason you can't shoot at f1.4 at high-noon on a bright sunny day. Back when most cameras topped-out at about 1/1000th of a second, this wasn't possible without the use of ND filters. Today, most consumer and all pro (D)SLRs, top out at 1/4000th to 1/8000th of a second, which offers us far more exposure and depth-of-field options. Even for fill-flash applications, several manufacturers offer TTL Speedlites that can be configured to sync at shutter-speeds of up to 1/16,000 of a second. You want blackened skies with razor-thin depth-of-field at high-noon? No problem.
The f-stop threshold of 'ultra-fast' varies as you go thru the focal-length range. Most every manufacturer has a 50/1.4 in their optical line-up, as well as lenses in the 200, 300, and 400-plus range with maximum apertures of f2.8. The fastest zoom lenses, both wide and long, also top out at f2.8.
While you can find 35, 28 and 24mm lenses that open up to f1.4, wider-angle optics (21mm-and-wider) seldom, if ever, come faster than f2.8. Sigma fans can opt for a 30mm F1.4 EX DC HSM (for use with APS-DSLRs only) and a choice of a 24 and 28mm, both featuring maximum apertures of f/1.8.
The widest of apertures can be found among 'normal' lenses with Leica's Noctilux-M 50/1 weighing in as the current high-speed champion. If you are Nikon-based, you might try finding a used Noct Nikkor 58/1.2, a discontinued manual-focus lens that displayed wonderful shallow-focus characteristics all while keeping lens flair well under control. (Note- The Noct Nikkor 58/1.2 should not be confused with the similar vintage, non-aspheric, and less expensive Ai Nikkor 50/1.2s.) If you're a Canon shooter sit tight for the recently-announced 50/1.2L EF, which should be available before the end of the year.
For short-telephoto imaging, there is a nice choice of high-speed 'portrait' lenses that include an 85/1.4 from Nikon and an 85/1.2L from Canon. This fall Sony will be rolling out the Planar T* 85/1.4 ZA along with a Sonnar T* 135/1.8 ZA for the new Sony Alpha A100.
Leica has a Summilux-R 80/1.4 for its reflex cameras (R8 and R9) and a Summilux-M 75/1.4 for its venerable rangefinder line. When Leica introduces their long-awaited Digital-M this Fall, the Summilux-M 75/1.4 will translate into an effective 97.5/1.4 (after the 1.3x magnification factor), which should prove to be a very cool portrait lens.
With the exception of a few lenses that open up to f1.8, most optics in the 100 to 135mm range max out at f2. Nikon's 200/2G ED-IF AF-S VR and Leica's Apo-Summicron 180/2 are the only other longer lenses that hit the f2 mark. Olympus' 150mm f/2.0 EP Zuiko Digital Lens, designed for use on Olympus' 4/3-series cameras, is the equivalent of a 300/2 on a full-frame 35!
From this point onward the widest apertures you will find are f2.8 to f4, which can be had in focal lengths of up to 600mm. Just don't expect to stroll around town wearing one of these monsters around your neck. Unless you're really steady, you should use a sturdy tripod or monopod when shooting with most any lens over 300mm, f2.8 or otherwise. And remember - lift with your knees - you don't want to hurt yourself.
Depth-of-field aside, another benefit of wider-aperture lenses is improved performance levels from the camera's AF and metering systems. Shutter-response times between a wide-aperture lens is noticeably quicker than a smaller-aperture lens. When manufacturer's brag about how fast their camera's AF-response times are you can be sure they weren't using the $99 kit lens when they ran the numbers.
Fast glass tends to be more expensive than their slower counterparts. The precision required to contain the various elements in proper alignment for sharp wide-aperture imaging is quite critical. With the exception of most current 50/1.4s and 85/1.8s, you seldom see 'plastic' lens barrels on prime high-speed optics. Most all of the above-mentioned lenses are constructed of metal alloys, incorporate the latest flair-reducing lens coatings, and are better sealed against the elements as compared to their slower siblings. Even if low-light or wide-aperture shooting is not an everyday event in your life, the benefits of these wide-eyed optics more than justify their higher purchase prices.
So now you might ask "Don't Image Stabilization (IS) and Vibration Reduction (VR) technologies do a terrific job at maintaining image sharpness at less-than-desirable shutter speeds?" The answer is, "yes they do". These days it's possible to handhold a lens with a maximum aperture of f2.8 with the same agility and precision as a Leica 50/1 Noctilux. The difference is an image captured at f2.8 will never have the same look as the same shot taken at f1. It might be just as sharp, but the fall-off between what is sharp and what isn't sharp will differ greatly.
I would be totally amiss if I spoke about wide-aperture imaging without mentioning 'bokeh'. Bokeh is a Japanese phrase used to describe the aesthetic qualities of the portion of the photograph that isn't in focus. These days most any lens you can buy is capable of taking a sharp picture. For many enthusiasts however, the mark of a truly good lens is how the lens visually interprets out-of-focus areas.
With many lenses, out-of-focus highlight areas take on a hex or octagon shape. This is the result of the lens replicating the shape of the diaphragm blades within highlight areas. If you only have 7 or 8 diaphragm blades, it's difficult to create a rounded diaphragm opening. If the f-stop is created with a dozen or more blades, the resulting opening becomes smoother and rounder, and rounder apertures ultimately result in smoother transitions between image tones. The effect is subliminal, but once you're keyed into it, it becomes hard not to notice it.
Leica-holics have long recognized this quality. The good news is that most of the major lens manufacturers have recognized the desirable qualities of bokeh. If you read the press blurbs for many upper-tier lenses you will note the mention of "rounded diaphragm blades to insure a more 'natural' look to your photographs". Guess what they're referring to. The photographs accompanying this article were shot using a Canon 85/1.2L EF, a lens that does a truly wonderful job capturing the unique optical qualities described in the above text.
'Barry Lyndon' - Stanley Kubrick Shoots a Movie at f/.095
Stanley Kubrick was an absolute perfectionist when it came to making movies. Back in 1975 he took on a film project called Barry Lyndon, a lush period piece set in 18th century Ireland. To capture the look and feel of the time, he shot all of the interiors by natural light, which back in the 18th century meant candles, oil lamps and torches. To accomplish this goal he made use of special high-speed lenses developed for NASA, as well as a 50/.095 lens made for the Canon 7s, a Leica-style rangefinder camera that was popular at the time.
Visually speaking, the results were breathtaking. The depth of field was so narrow that the actors had to avoid any back-and-forth movements during close-up shots. Low Kelvin ratings (candles are about 800-degrees Kelvin), reciprocity failure due to film being pushed to it's technical limitations, mixed with ridiculously narrow depth-of-field created the illusion of watching an animated oil painting. Even the exterior shots were amazing to look at, as they were all shot at sunrise and sunset. Exposure options available to us today, thanks in part to flexible ISO-ratings and widely adjustable White Balance controls, make for truly exciting low-light imaging possibilities. After viewing Barry Lyndon you might want to trade in your bag of Speedlites for a faster lens, a powder wig, and, hey, you never know, a silver snuff box.
A Selection of wide-Aperture Lenses Currently Available at B&H Photo: