The biggest challenge photographers face when shooting nature close-ups is how to get a sharp image.
So much is working against us when we're shooting close-ups: movement; a narrow depth of field; difficulties with focus; and getting good resolution, even in low light. As the sign on my desk says: It’s never easy.
But taking on such challenges is part of the fun and creativity of photography. So, in this article, prepared exclusively for the Adorama Learning Center, let’s look at some ways to get the sharper image we want in our close-ups despite all the obstacles.
Go for high resolution
If you’re into the technical aspects of digital photography, you know about pixels and you know that the more pixels in your image, the greater the resolution or potential sharpness. For greatest resolution, shoot RAW or opt for the best quality JPEG file. Your images will use up more memory on your card and computer, but you’ll have that extra edge in sharpness.
Also, in general, use the lowest ISO you can to maintain optimum resolution in your image. But, as you’ll see, even this rule may have to be broken.
If your flower is swaying in the breeze or your butterfly is flapping its wings, you won’t get a decent close-up unless you can freeze those movements.
The simplest way to do that is by using a fast shutter speed. Luckily, with today’s digital cameras, you can use your fastest shutter speed together with a small aperture. However, that combination may only work if you compensate for any loss of exposure by pushing your ISO up to 800 or even 1600. One of the great perks of digital photography is that you can change your ISO setting any time you want – even for just one shot.
Will you lose any resolution at higher ISO settings? If you are shooting with a DSLR or interchangeable-lens camera with a Four Thirds or larger sensor, you may lose a bit but you’ll still get good resolution—and any small loss of resolution is more than offset by getting better sharpness with a faster shutter speed and small aperture setting.
Another way to stop motion is to by adding light with a flash. Adorama carries a full line of macro flash gear. Again, this lets you use a faster shutter speed. And, as a bonus, if you fire your flash off the camera, you can direct the light to create contrast exactly where you want it. Contrast helps give the impression of sharpness because it defines the line separating brighter and darker areas. You can achieve this effect by setting your subject against a contrasting color or shadow area. Or you can increase contrast by using your flash to simulate backlight or sidelight, increasing the contrast between your subject and the background.
You’ll also want to minimize any movement you may be creating, since working at close range exaggerates camera shake. That’s why it’s very important to work with a tripod. Not only does a tripod keep your camera steady; it also lets you set up those hard-to-reach shots, like mountain-hugging wildflowers, without twisting yourself into a pretzel or throwing your back out. With your camera safely on a tripod, you also can take the extra step of using a self-timer or cable release to eliminate even the smallest amount of camera vibration.
Working with a narrow depth of field
Depth of field refers to the range of sharpness from front to back that your camera and lens can provide in an image. A number of factors determine the depth of field. The one that affects anyone shooting close-ups is how far you are from your subject. With most macro work done at close range, your depth of field is quite narrow – less than 2mm in life-size close-up photography. That means that only a thin slice of the image, before and behind what you are focused on, can be really sharp.
This is a matter of optics, not the quality of your equipment. It is virtually impossible with three-dimensional close-ups to have everything in focus. But don’t despair; with a little know-how and ingenuity you can have a beautiful close-up image.
You can maximize your depth of field and maintain high resolution by using the aperture setting one up from the smallest one you have. That’s right – because the quality of a lens is best in middle aperture range, if you use your smallest aperture setting – e.g. f/22 — you’ll lose some sharpness compared with the same lens set at f/16. The slight decrease in depth of field is offset by increased sharpness.
Also, experiment with various angles on your subject to find a perspective that gives you the best depth of field and sharpness. For example, you may need more or less depth of field shooting a side view of a flower than a frontal perspective. Check to see the difference.
Most important, though, you must make a conscious decision on where to focus. Therefore, you have to think about what is most important to your image so you focus on that element. Then, be creative with the out-of-focus parts of your image.
(These tips are for maximizing depth right out of the camera. Learn about how to composite multiple images to increase percieved depth in macro photos using Photoshop.)
Keeping your focus
While the automatic features in today’s digital SLRs often take the guesswork out of photography, when it comes to focusing on close-ups, you’d be better off using the manual override. That’s because the autofocus feature works best when there’s a clear area for the lens to lock in on. But that’s usually not the case when we shoot close-ups with our macro lens. In fact, your lens will go bananas trying to find something to lock in on. By working with manual focus, you can decide what you want to focus on and lock into it when you are satisfied with what you see through your lens.
Be especially careful when the element you are focusing on is at the center of your image. Remember that with a narrow depth of field, everything toward the edges of the frame will tend to be out of focus. If you have a bright, blurred area at the lower edge closest to your lens, it could dominate your composition and draw the viewer’s eye away from your actual focal point. If you see a bright area along the lower edge, recompose or focus on something in the bright area and create a composition around that.