|This Article Features Photo Zoom|
We took a Tamron SP 90mm F/2.8 Di VC USD lens into the field to shoot everything from close-ups to broad scenics. Your macro isn't limited to small stuff.
The Face Of The Landscape
In traditional terms, the focal-length range from 80mm to 135mm has been considered ideal for portraits. There's something about the modest compression that flattens facial perspective while drawing close to lips and eyes. This has changed, to some degree, in more recent years. One, with the advent of sub-frame digital cameras, this focal-length range is cropped by the sensor to act like about 1.5X. Also, it became popular for swimsuit photographers to use as much as 300mm or more for the special effects of soft backgrounds, enlarging sunset backdrops in relation to the subject and more.
Nevertheless, in similar terms, a case can be made that landscapes look best when photographed with this portrait lens range. This is particularly true for landscapes with big features like massive mountains or old-growth trees (Photo 1). The moderate magnification and special compression draw distant subjects closer while rendering them larger in relation to the foreground. The result is a more imposing photograph. Of course, it's easy to use a wide variety of zooms in the range between 90mm and 135mm, but for our case at hand, we thought it would be novel to make use of the specialty 90mm macro as the less obvious choice. The justifications are these.
|You can see the differences in background sharpness between ƒ/6.3 (above) and ƒ/8 (below). We prefer the less-distracting ƒ/6.3 version.|
Dedicated macro lenses are designed for optimum sharpness across the frame, and as prime lenses, they're usually fast, with maximum apertures of ƒ/2.8 or greater. Compared with zoom lenses that often feature variable apertures, a fast prime macro is shooting at its sweet spot around ƒ/5.6 or ƒ/8. For all these reasons, outdoor photographers may actually find that owning a 90mm macro provides more utility than a straightforward prime in the same focal range—you get the key benefits of a fast prime, plus the benefits of a macro lens.
There's a massive gap between a big landscape and an up-close extreme macro. In this zone, one can find the sort of intimate scene that shows natural structures like flowers with some of their context. Instead of a tight shot of the edge of a petal or a flower stamen, these intimate scenes can tell a story of the flower in its place while still making a casual viewer sit up and take notice of the flower's details. The 90mm range of a typical macro lens can do a remarkable job with these types of photos. It also gives you a comfortable working distance thanks to its slight telephoto focal length. When you do back off slightly from 1:1 macro, pay particular attention to the depth of field.
|This Article Features Photo Zoom|
|Once again, the ƒ-stop choice is personal. Here, ƒ/5.6 softens some of the background detail. But you may also prefer the tapestry of texture afforded by ƒ/16.|
Depth of field in macro shots is very much a matter of taste (Photos 2 and 3). Even the small differences between ƒ/6.3 and ƒ/8 can be seen, particularly in regard to the background. We would choose ƒ/6.3 because the white flowers have a comfortable amount of detail to still be recognizable, but beyond that, all the background clutter is taken out of play in soft focus. Generally, macro photos are most pleasing when the controlled depth of field draws attention to the primary subject while providing some sense of place, but with limited interference. Think of them like actors on a stage. You want focus on the speaking character while the supporting actors need to be engaged, but not distracting. Shoot multiple exposures with close ƒ-stop differences so you can view the subtle differences on the big screen before making your final frame choice. It's too hard to discern this degree of detail on a small LCD outdoors.
For very vertical flowers like paintbrush (Photo 6), you may not be able to carry sufficient depth of field to keep the whole flower structure sharp. Here, even ƒ/9 will only hold the top petals in focus. Look for opportunities where a pinhole light illuminates the flower like a key light in a studio. This effect works with limited depth of field rather than against it, resulting in a pleasing image.
Textures & Patterns
A 90mm macro does an excellent job with textures and patterns. These omnipresent subjects can be quite mesmerizing, and on days of poor lighting conditions for landscapes, you can almost always find interesting patterns and textures to photograph. The macro lens is well suited because it's designed to have minimal distortion and even illumination from edge to edge and corner to corner. When shooting these subjects, be cautious of careless focus.
In Photo 7, at ƒ/3.2, it's easy to be careless with depth of field because our eye tends to see the tree trunk as flat when looking through the viewfinder. Consequently, the left and lower areas of the frame aren't sharp in this simple composition that should have been easy to make perfect. Again, bracketing for depth of field is a good idea and will save you a lot of frustration when you get home.
|Left: It should have been easy to make this shot perfectly sharp, but we forgot about the curvature of the trunk while looking through the viewfinder. ƒ/3.2 didn't give sufficient depth of field, and we lost sharpness at the corner.|
When shooting a rather flat surface for the interest in texture (Photo 8), it's not necessary to go overboard with a small ƒ-stop beyond ƒ/16. An increase in depth of field can be mitigated by unacceptable amounts of diffraction. Do some tests with your own macro to get a sense of the trade-off between depth of field at smaller apertures and diffraction.
|This Article Features Photo Zoom|
Meaning In The Mundane
Pretty petals are often the primary focus of close-ups, but the macro view can create interest in dried stems, grasses and thistles (Photo 9). Low, early or late backlight draws attention to shape over color and sets golden highlights against the blue shade of an out-of-focus background.
Of course, the primary reason anyone chooses a macro lens is to do extreme close-ups at magnifications at or close to 1:1. The term "macro" doesn't have a universally agreed-upon definition. Some use it loosely as a synonym for any close-up while others claim that a 1:1 magnification ratio is necessary.
The 1:1 magnification ratio means that you can render the subject at life-size on the sensor. A flower that measures one inch across can be photographed so that it will be the same one inch on the sensor.
This article touches on many of the other qualities that are common to macro lenses. Sharp focus across the frame with no light fall-off at the corners at any aperture is a particular hallmark of a macro prime. Why wouldn't all lenses behave this way? To do what they do, many macro lenses don't feature internal focusing, and because of their emphasis on close-ups, people who never shoot macro will find them less comfortable as a general-purpose lens. However, as we point out, anyone who does shoot macro will find they can multitask quite well.
The Tamron SP 90mm F/2.8 Di VC USD MACRO 1:1 with eBand Coating was used for this article. It measures 4.5 inches at infinity, weighs 19.4 ounces and takes 58mm filters. The minimum focus distance is 11.8 inches, it's compatible with full-frame and APS-C DSLRs, and it's available for Nikon (with built-in motors), Canon and Sony mounts. The estimated street price is $749. For more details, go to www.tamron-usa.com.