Posted on October 14, 2018
What’s the point?
It seems like one of photography’s great mysteries is achieving proper focus: the camera settings, where to place the focus point, even the definition of sharpness are all sources of confusion and angst. If you’re a tourist just grabbing snapshots, everything in your frame is likely at infinity and you can just put your camera in full auto mode and click away. But if you’re a photographic artist trying to capture something unique with your mirrorless or DSLR camera and doing your best to have important visual elements objects at different distances throughout your frame, you need to stop letting your camera decide your focus point and exposure settings.
Of course the first creative focus decision is whether you even want the entire frame sharp. While some of my favorite images use selective focus to emphasize one element and blur the rest of the scene, most (but not all) of what I’ll say here is about using hyperfocal techniques to maximize depth of field (DOF). I cover creative selective focus in much greater detail in another Photo Tip article: Creative Selective Focus.
Beware the “expert”
I’m afraid that there’s some bad, albeit well-intended, advice out there that yields just enough success to deceive people into thinking they’ve got focus nailed, a misperception that often doesn’t manifest until an important shot is lost. I’m referring to the myth that you should focus 1/3 of the way into the scene, or 1/3 of the way into the frame (two very different things, each with its own set of problems).
For beginners, or photographers whose entire scene is at infinity, the 1/3 technique may be a useful rule of thumb. But taking the 1/3 approach to focus requires that you understand DOF and the art of focusing well enough to adjust your focus point when appropriate, and once you achieve that level of understanding, you may as well do it the right way from the start. That ability becomes especially important in those scenes where missing the focus point by just a few feet or inches can make or break and image.
Back to the basics
Understanding a few basic focus truths will help you make focus decisions:
Depth of field discussions are complicated by the fact that “sharp” is a moving target that varies with display size and viewing distance. But it’s safe to say that all things equal, the larger your ultimate output and closer the intended viewing distance, the more detail your original capture should contain.
To capture detail a lens focuses light on the sensor’s photosites. Remember using a magnifying glass to focus sunlight and ignite a leaf when you were a kid? The smaller (more concentrated) the point of sunlight, the sooner the smoke appeared. In a camera, the finer (smaller) a lens focuses light on each photosite, the more detail the image will contain at that location. So when we focus we’re trying to make the light striking each photosite as concentrated as possible.
In photography we call that small circle of light your lens makes for each photosite its “circle of confusion.” The larger the CoC, the less concentrated the light and the more blurred the image will appear. Of course if the CoC is too small to be seen as soft, either because the print is too small or the viewer is too far away, it really doesn’t matter. In other words, areas of an image with a large CoC (relatively soft) can still appear sharp if small enough or viewed from far enough away. That’s why sharpness can never be an absolute term, and we talk instead about acceptable sharpness that’s based on print size and viewing distance. It’s actually possible for the same image to be sharp for one use, but too soft for another.
So how much detail do you need? The threshold for acceptable sharpness is pretty low for an image that just ends up on an 8×10 calendar on the kitchen wall, but if you want that image large on the wall above the sofa, achieving acceptable sharpness requires much more detail. And as your print size increases (and/or viewing distance decreases), the CoC that delivers acceptable sharpness shrinks correspondingly.
Many factors determine the a camera’s ability to record detail. Sensor resolution of course—the more resolution your sensor has, the more important it becomes that to have a lens that can take advantage of that extra resolution. And the more detail you want to capture with that high resolution sensor and tack-sharp lens, the more important your depth of field and focus point decisions become.
The foundation of a sound approach to maximizing sharpness for a given viewing distance and image size is hyperfocal focusing, an approach that uses viewing distance, f-stop, focal length, and focus point to ensure acceptable sharpness.
The hyperfocal point is the focus point that provides the maximum depth of field for a given combination of sensor size, f/stop, and focal length. Another way to say it is that the hyperfocal point is the closest you can focus and still be acceptably sharp to infinity. When focused at the hyperfocal point, your scene will be acceptably sharp from halfway between your lens and focus point all the way to infinity. For example, if the hyperfocal point for your sensor (full frame, APS-C, 4/3, or whatever), focal length, and f-stop combinition is twelve feet away, focusing there will give you acceptable sharpness from six feet (half of twelve) to infinity—focusing closer will soften the distant scene; focusing farther will keep you sharp to infinity but extend the area of foreground softness.
Because the hyperfocal variable (sensor size, focal length, f-stop) combinations are too numerous to memorize, we usually refer to an external aid. That used to be awkward printed tables with long columns and rows displayed in microscopic print, the more precise the data, the smaller the print. Fortunately, those have been replaced by smartphone apps with more precise information in a much more accessible and readable form. We plug in all the variables and out pops the hyperfocal point distance and other useful information
It usually goes something like this:
You’re not as sharp as you think
Since people’s eyes start to glaze over when CoC comes up, they tend to use the default returned by the smartphone app. But just because the app tells you you’ve nailed focus, don’t assume that your work is done. An often overlooked aspect of hyperfocal focusing is that app makes assumptions that aren’t necessarily right, and in fact are probably wrong.
The CoC your app uses to determine acceptable sharpness is a function of sensor size, display size, and viewing distance. But most app’s hyperfocal tables assume that you’re creating an 8×10 print that will be viewed from a foot away—maybe valid 40 years ago, but not in this day of mega-prints. The result is a CoC three times larger than the eye’s ability to resolve.
That doesn’t invalidate hyperfocal focusing, but if you use published hyperfocal data from an app or table, your images’ DOF might not be as ideal as you think it is for your use. If you can’t specify a smaller CoC in your app, I suggest that you stop-down a stop or so more than the app/table indicates. On the other hand, stopping down to increase sharpness is an effort of diminishing returns, because diffraction increases as the aperture shrinks and eventually will soften the entire image—I try not to go more than a stop smaller than my data suggests.
Keeping it simple
As helpful as a hyperfocal app can be, whipping out a smartphone for instant in-the-field access to data is not really conducive to the creative process. I’m a big advocate of keeping photography as simple as possible, so while I’m a hyperfocal focus advocate in spirit, I don’t usually use hyperfocal data in the field. Instead I apply hyperfocal principles in the field whenever I think the margin of error gives me sufficient wiggle room.
Though I don’t often use the specific hyperfocal data in the field, I find it helps a lot to refer to hyperfocal tables when I’m sitting around with nothing to do. So if I find myself standing in line at the DMV, or sitting in a theater waiting for a movie (I’m a great date), I open my iPhone hyperfocal app and plug in random values just to get a sense of the DOF for a given f-stop and focal length combination. I may not remember the exact numbers later, but enough of the information sinks in that I accumulate a general sense of the hyperfocal DOF/camera-setting relationships.
Finally, something to do
Unless I think I have very little DOF margin for error in my composition, I rarely open my hyperfocal app in the field. Instead, once my composition is worked out and have determined the closest object I want sharp—the closest object with visual interest (shape, color, texture), regardless of whether it’s a primary subject.
Of course these distances are very subjective and will vary with your focal length and composition (not to mention the strength of your pitching arm), but you get the idea. If you find yourself in a small margin for error focus situation without a hyperfocal app (or you just don’t want to take the time to use one), the single most important thing to remember is to focus behind your closest subject. Because you always have sharpness in front of your focus point, focusing on the closest subject gives you unnecessary sharpness at the expense of distant sharpness. By focusing a little behind your closest subject, you’re increasing the depth of your distant sharpness while (if you’re careful) keeping your foreground subject within the zone of sharpness in front of the focus point.
And finally, foreground softness, no matter how slight, is almost always a greater distraction than slight background softness. So, if it’s impossible to get all of your frame sharp, it’s usually best to ensure that the foreground is sharp.
Why not just automatically set my aperture to f/22 and be done with it? I thought you’d never ask. Without delving too far into the physics of light and optics, let’s just say that there’s a not so little light-bending problem called “diffraction” that robs your images of sharpness as your aperture shrinks—the smaller the aperture, the greater the diffraction. Then why not choose f/2.8 when everything’s at infinity? Because lenses tend to lose sharpness at their aperture extremes, and are generally sharper in their mid-range f-stops. So while diffraction and lens softness don’t sway me from choosing the f-stop that gives the DOF I want, I try to never choose an aperture bigger or smaller than I need.
Now that we’ve let the composition determine our f-stop, it’s (finally) time to actually choose the focus point. Believe it or not, with this foundation of understanding we just established, focus becomes pretty simple. Whenever possible, I try to have elements throughout my frame, often starting near my feet and extending far into the distance. When that’s the case I stop down focus on an object slightly behind my closest subject (the more distant my closest subject, the farther behind it I can focus).
When I’m not sure, or if I don’t think I can get the entire scene sharp, I err on the side of closer focus to ensure that the foreground is sharp. Sometimes before shooting I check my DOF with the DOF preview button, allowing time for my eye to adjust to the limited light. And when maximum DOF is essential and I know my margin for error is small, I don’t hesitate to refer to the DOF app on my iPhone.
A great thing about digital capture is the instant validation of the LCD—when I’m not sure, or when getting it perfect is absolutely essential, after capture I pop my image up on the LCD, magnify it to maximum, check the point or points that must be sharp, and adjust if necessary. Using this immediate feedback to make instant corrections really speeds the learning process.
Sometimes less is more
The depth of field you choose is your creative choice, and no law says you must maximize it. Use your camera’s limited depth of field to minimize or eliminate distractions, create a blur of background color, or simply to guide your viewer’s eye. Focusing on a near subject while letting the background go soft clearly communicates the primary subject while retaining enough background detail to establish context. And an extremely narrow depth of field can turn distant flowers or sky into a colorful canvas for your subject.
There’s no substitute for experience
No two photographers do everything exactly alike. Determining the DOF a composition requires, the f-stop and focal length that achieves the desired DOF, and where to place the point of maximum focus, are all part of the creative process that should never be left up to the camera. The sooner you grasp the underlying principles of DOF and focus, the sooner you’ll feel comfortable taking control and conveying your own unique vision.
About this image
Yosemite may not be New England, but it can still put on a pretty good fall color display. A few years ago I arrived at Valley View on the west side of Yosemite Valley just about the time the fall color was peaking. I found the Merced River filled with reflections of El Capitan and Cathedral Rocks, framed by an accumulation of recently fallen leaves still rich with vivid fall color.
To emphasize the colorful foreground, I dropped my tripod low and framed up a vertical composition. I knew my hyperfocal distance at 24mm and f/11 would be 5 or 6 feet, but with the scene ranging from the closest leaves at about 3 feet away out to El Capitan at infinity, I also knew I’d need to be careful with my focus choices. For a little more margin for error I stopped down to f/16, then focused on the nearest rocks which were a little less than 6 feet away. As I usually do when I don’t have a lot of focus wiggle room, I magnified the resulting image on my LCD and moved the view from the foreground to the background to verify front-to-back sharpness.
Click an image for a closer look and slide show. Refresh the screen to reorder the display.
Posted on September 27, 2018
As we enter the fall color photography season, I’m revisiting and revising previous articles. This is the second in the series.
Vivid color and crisp reflections make autumn my favorite season for creative photography. While most landscape scenes require showing up at the right time and hoping for the sun and clouds to cooperate, photographing fall color is often a simple matter of circling the scene until the light’s right. For the photographers who understand this, and know how to control exposure, depth, and motion with their cameras, great fall color images are possible any time of day, in any light.
Backlight, backlight, backlight
The difference between the front-lit and backlit sides of fall foliage is the difference between dull and vivid color. When illuminated by direct sunlight, the side of a leaf opposite the sun throbs with color, as if it has its own source of illumination, while the same leaf’s lit side appears flat—if you ever find yourself thinking that the fall color seems washed out, check the other side of the tree.
While the backlight glow isn’t as pronounced in shade/overcast, when the leaves are illuminated by light that’s spread evenly across the sky, even diffuse sunlight is far more pronounced one side of the leaves than the other, giving the side of a leaf that’s opposite the sky (the side getting less light) a subtle but distinct glow when compared to its skyward side.
Isolate elements with a telephoto for a more intimate fall color image
Big fall color scenes are great, but a telephoto or macro enables you to highlight and emphasize elements and relationships. Train your eye to find leaves, groups of leaves, or branches that stand out from the rest of the scene. Zoom close, using the edges of the frame to eliminate distractions and frame subjects. And don’t concentrate so much on your primary subject that you miss complementary background or foreground elements to balance the frame and provide an appealing canvas for your subject.
Selective depth of field is a great way to emphasize/deemphasize elements in a scene
Limiting depth of field with a large aperture on a telephoto lens can soften a potentially distracting background into a complementary canvas of color and shape. Parallel tree trunks, other colorful leaves, and reflective water make particularly effective soft background subjects. For an extremely soft background, reduce your depth of field further by adding an extension tube to focus closer.
Underexpose sunlit leaves to maximize color
Contrary to what many believe, fall foliage in bright sunlight is still photographable if you isolate backlit leaves against a darker background and slightly underexpose them. The key here is making sure the foliage is the brightest thing in the frame, and to avoid including any sky in the frame. Photographing sunlit leaves, especially with a large aperture to limit DOF, has the added advantage of an extremely fast shutter speed that will freeze wind-blown foliage.
Slightly underexposing brightly lit leaves not only emphasizes their color, it turns everything that’s in shade to a dark background. And if your depth of field is narrow enough, points of light sneaking between the leaves and branches to reach your camera will blur to glowing jewels.
A sunstar is a great way to liven up an image in extreme light
If you’re going to be shooting backlit leaves, you’ll often find yourself fighting the sun. Rather than trying to overcome it, turn the sun into an ally by hiding it behind a tree. A small aperture (f16 or smaller is my general rule) with a small sliver of the sun’s disk visible creates a brilliant sunstar that becomes the focal-point of your scene. Unlike photographing a sunstar on the horizon, hiding the sun behind a terrestrial object like a tree or rock enables you to move with the sun.
When you get a composition you like, try several frames, varying the amount of sun visible in each. The smaller the sliver of sun, the more delicate the sunstar; the more sun you include, the more bold the sunstar. You’ll also find that different lenses render sunstars differently, so experiment to see which lenses and apertures work best for you.
Polarize away the foliage’s natural sheen
Fall foliage has a reflective sheen that dulls its natural color. A properly oriented polarizer can erase that sheen and bring the underlying natural color into prominence. To minimize the scene’s reflection, slowly turn the polarizer until the scene is darkest (the more you try this, the easier it will be to see). If you have a hard time seeing the difference, concentrate your gaze on a single leaf, rock, or wet surface.
A polarizer isn’t an all-on or all-off proposition. Slowly dial the polarizer’s ring and watch the reflection change until you achieve the effect you desire. This is particularly effective when you want your reflection to share the frame with submerged feature such as rocks, leaves, and grass.
Blur water with a long exposure
When photographing in overcast or shade, it’s virtually impossible to freeze the motion of rapid water at any kind of reasonable ISO. Rather than fight it, use this opportunity to add silky water to your fall color scenes. There’s no magic shutter speed for blurring water—in addition to the shutter speed, the amount of blur will depend on the speed of the water, your distance from the water, your focal length, and your angle of view relative to the water’s motion. When you find a composition you like, don’t stop with one click. Experiment with different shutter speeds by varying the ISO (or aperture as long as you don’t compromise the desired depth of field).
Reflections make fantastic complements to any fall color scene
By autumn, rivers and streams that rushed over rocks in spring and summer, meander at a leisurely, reflective pace. Adding a reflection to your autumn scene can double the color, and also add a sense of tranquility. The recipe for a reflection is still water, sunlit reflection subjects, and shaded reflective surface.
When photographing leaves floating atop a reflection, it’s important to know that the focus point for the reflection is the focus point of the reflective subject, not the reflective surface. This is seems counterintuitive, but try it yourself—focus on the leaves with a wide aperture and watch the reflection go soft. Achieving sharpness in your floating leaves and the reflection requires an extremely small aperture and careful focus point selection. Often the necessary depth of field exceeds the lens’s ability to capture it—in this case, I almost always bias my focus toward the leaves and let the reflection go soft.
Nothing communicates impending winter like fall color with snow
Don’t think the first snow means your fall photography is finished for the year. Hardy autumn leaves often cling to branches, and even retain their color on the ground through the first few storms of winter. An early snowfall is an opportunity to catch fall leaves etched in white, an opportunity not to be missed. And even after the snow has been falling for a while, it’s possible to find a colorful rogue leaf to accent an otherwise stark winter scene.
To better understand the science and timing of fall color, read
Posted on December 21, 2014
Lots of variables go into creating a successful landscape image. Many people struggle with the scene variables—light, depth, and motion—that are managed by your camera’s exposure settings: shutter speed, f-stop, ISO. Others struggle more with the composition variables: identifying, isolating, and framing a subject. (I’m not denying that there’s overlap between the exposure and composition sides of image creation, but leveraging that overlap requires independent mastery of both sides.)
Getting the exposure variables out of the way
Because I want to write more about the composition decisions that went into this image, I’ll only touch briefly on my exposure choices for the above image. I approach every scene with at my camera’s best ISO (100) and lens’s “ideal” f-stop (generally f11, where lenses tend to be sharpest, the depth of field is good, and diffraction is minimal).
Given that motion wasn’t a factor (I was on a tripod, the wind was calm, and the river’s motion didn’t concern me), I stuck with ISO 100. And even though the submerged rocks provided lots of visual interest in the immediate foreground, my 16mm focal length provided more than enough depth of field at f11—focusing about four feet into the scene would give me sharpness from around two feet to infinity. That was easy.
With those two variables established, I spot-metered on the brightest part of the scene and set dialed my shutter speed until the exposure was as bright as felt I could get away with without hopelessly blowing the highlights. This ensured that my scene (shadows included) was as bright as I could safely make it.
Here’s what I was thinking
Reflections of El Capitan, Cathedral Rocks, and Bridalveil Fall make Valley View one of the most photographed locations in Yosemite Valley. I usually I try to find something a little different than the standard view here, but the cloudy vestiges of a passing storm reflecting in the Merced River provide an irresistible opportunity to take advantage of everything that makes Valley View so special.
Some scenes you can walk up to and plant your tripod pretty much anywhere without much difference in your background subjects (though that’s rarely the case with foreground/background relationships). That’s not the case at Valley View, where the difficulty starts with distracting, non-photogenic shrubs on the near riverbank—to keep them out of the frame, you need to hop the rocks all the way down to the river.
The bigger problem at Valley View is getting all the primary elements into the image—too far to the left, and El Capitan disappears behind a stand of evergreens; too far to the right and another stand of evergreens occludes most or all of Bridalveil Fall. I moved into the fifteen-foot section of riverbank that gives me what I consider an adequate view of both, and started studying the submerged and protruding rocks right in front of me, looking for a workable foreground.
I’ll often move around quite a bit to control foreground/background subject relationships; in this case I found little benefit from shifting and stayed more or less in the same place. But that doesn’t mean I didn’t vary my shots—I tried a variety of compositions, but wide and tight, horizontal (above) and vertical (below). Some used lots of sky, while others (like this one) minimized the sky to emphasize the foreground. Still others were of the reflection only, or of the reflections with just a thin stripe of the opposite riverbank. The other variable I played with was my polarizer, which I turned to maximize and minimize the reflection, plus a combination (like both images here).
As with many images, composition at the top of the page required some compromises. I liked the way the vertical version leads the eye through the scene, and frames it with the two most striking elements—El Capitan and Bridalveil Fall. But I also wanted a horizontal rendering that would open up the scene and express its broad grandeur.
An often forgotten component of successful photography is what gets left out—an image’s perimeter are frequently home to distractions overlooked by photographers too drawn to their primary subjects. So the problem making a Valley View horizontal composition that’s wide enough to include the reflection and river rocks, is the introduction of potentially distracting elements on the far left and right.
In this case my greatest problem was the scene’s left side, with its bare trees, brown riverbank, and exposed rocks, it was rife with potential distractions to deal with. Shifting the entire composition to the right would have thrown the frame off balance, and added a lot of real estate that wasn’t worthy of the scene. Going tighter would have sacrificed too much river rock and reflection, an essential feature in my mind. I could have removed my shoes and socks, rolled up my pants, and walked forward through the (frigid) water—that move would have solved all my problems, but probably wouldn’t have been appreciated by all the other nearby photographers.
I ended up using the trees and rocks to frame the left side of the image, taking care to allow the entire arc of the riverbank to complete so it didn’t look like the nearby rocks (on the left) belonged a different scene. The vertical version doesn’t have these problems, and though it sacrifices the breadth of the horizontal composition, hold a gun to my head and I might tell you it’s the vertical version I prefer. (But it’s nice to have a choice.)