Tips For Ultimate Sharpness

When I teach a workshop, I encourage my students to take the sharpest picture possible. Afterward, if they want to soften an image with software for a creative or an artistic effect, that’s cool, easy and fun. There are several requirements for getting the sharpest in-camera shot. There are also several techniques for enhancing sharp shots in Lightroom, Photoshop and Aperture. In this article, we’ll take a look at some in-camera and postprocessing ideas for getting sharp shots. I say "some" because this entire magazine actually could be filled with sharpening ideas. The ones I share here are those that I consider to be the most important.

I’ll illustrate these tips with some of my favorite images from one of my Alaska workshops with Hal Schmitt, who heads up the Light Photographic Workshops in Los Osos, California (lightworkshops.com). All the photographs in the article were taken with a Canon EOS 5D Mark III and a variety of Canon lenses: 15mm, 24-105mm, 70-200mm and 100-400mm. All images were processed in Adobe Photoshop CS5.


BEST APERTURE


SHOOTING TECHNIQUES

Detailed Subject. If you’re looking for a sharp shot, you need a subject with details. For example, there are a lot of details in the feathers of the bald eagles in the photograph that opens this article. That’s one reason why the image looks sharp. If I had been looking for an image to illustrate a soft photograph, I would have perhaps chosen to use a close-up of a rose petal taken in soft, low light.

Strong Contrast. Contrast—the difference between shadows and highlights in a photograph, as well as the difference in colors of the subject and the background—also can make a difference in the apparent sharpness of a photograph. What’s more, photographs taken on overcast days tend to look softer than those taken on bright, sunny days.

Good Glass. Simply put, when it comes to choosing a lens, you get what you pay for. Invest in the best lens you can afford. That goes for teleconverters, too. Actually, that goes doubly for teleconverters. Go for the best. If you spend a few more bucks on a lens and teleconverter, you’ll never question your decision.

Best Aperture. Many lenses are sharpest around ƒ/8. That said, I’ve seen sharp shots taken with a 70-200mm lens set at ƒ/2.8, as well as with an 85mm lens set at ƒ/1.4. In addition, due to diffraction, you’ll get a sharper shot at ƒ/16 than you will at ƒ/22 or ƒ/32. Keep in mind that sharpness has nothing to do with depth of field. My advice is to test a lens at different apertures. A simple at-home test is to tape a newspaper to a wall, put your camera on a tripod, and take a series of exposures at different apertures. Also test for edge-to-edge sharpness. Some lenses produce images that are softer at the edges than they are in the middle of the frame.


GOOD GLASS

Fast Shutter Speed. When a subject is moving fast, you need a fast shutter speed to freeze the action. The faster the subject is moving, the faster the required shutter speed. I photographed the bald eagles using a shutter speed of 1?2000 sec.

Accurate Focus. Right-on focus is necessary to get the sharpest possible shot. When a subject is moving, set your camera to AI Servo focus (Canon) or Continuous Focus (Nikon). These settings (AI Servo, in this case) allow your camera to track a moving subject right up until the moment of exposure. How cool is that! When a subject isn’t moving, set your camera to one shot.

Depth Of Field. Pictures with shallow depth of field can lack apparent sharpness. In this photograph, the inflatable boat in the foreground, the boat in the middle of the photograph and the background are all in focus, which was my goal for the photograph. To achieve that goal, I set my 70-200mm lens to 85mm and shot at ƒ/5.6.


ISO

ISO. At high ISO settings, you’ll get more noise in an image than you’ll get at low ISO settings (although with some of the newer digital SLRs you can shoot at ISO well over 1000 and still get very clean images). Noise can make an image look soft, even if it’s sharp. My advice is always to shoot at the lowest possible ISO setting. That may be quite high if you’re handholding a shot in very low light. Still, go for the lowest setting. I took this handheld shot at sunset with the ISO set at 500.

Lens Hood. When direct light hits the front element of your lens or filter, you get lens flare. At its worst, lens flare shows up as a bright spot in your picture. To a lesser degree, lens flare can make a picture look soft. Always use a lens hood, or "flag" your lens with a hat or hand, to keep direct light off the front of your lens.

PROCESSING TECHNIQUES

Sharpening in the digital darkroom is one of the keys to making a good photograph. If I could give only one tip, it would be this: Don’t oversharpen an image. That’s something I see again and again in my portfolio reviews. All RAW files need sharpening—just don’t overdo it. Here are several sharpening options.


FAST SHUTTER SPEED

Unsharp Mask. My preferred sharpening technique is Unsharp Mask in Photoshop. When I use this technique, I place the most important part of the photograph in the image area in the dialog box since that’s the area I want to sharpen. More on this idea in the next topic.

Selective Sharpening. Speaking of the most important part of an image, I always sharpen selectively rather than sharpening the entire image. You want to sharpen selectively to draw more attention to the main subject in the viewfinder. In addition, you usually don’t want to sharpen dark and out-of-focus areas of a photograph because those areas are where noise shows up the most. Sharpening increases noise.

In Photoshop CS5, I go to Filter > Convert to Smart Filter. I select Unsharp Mask and sharpen the entire image—but I’m only paying attention to how the sharpening affects the main subject. After clicking OK, I select black as the foreground color, select a brush and "paint out" the area of the image I don’t want sharpened (which shows up as black on the Smart Filters layer in the Layers panel).

Contrast Adjustments. Increasing contrast can increase the apparent sharpness of an image. I use Curves to do that. To preserve the highlights and shadows, I move the top and bottom of the curve inward just a tad. Then I click on the middle of the curve to set a control point. As a final step, I click on part of the curve and move it upward to create what’s called an "S" curve, which increases contrast.

Blurring The Background. Blurring the background also can increase the apparent sharpness of a subject. You can do this using the Convert to Smart Filter technique described above, using the Gaussian filter, in this case.

As I mentioned at the beginning of this article, there are other sharpening ideas and techniques, but I’ve focused on the most important. The ideas I shared here are designed to get you started on setting your sights on sha
rp shots. Set your sights high, my friends!

Rick Sammon is a regular here at Digital Photo magazine. For more information on Rick, you can check out his website at www.ricksammon.info.

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