Tips for Adjusting Image Sharpness in Digital Photographs

Getting a nice clean, sharp image that has perfect focus is the result of good camera work. If you have an image that is sharp and in focus but you want to make it "pop" even more computer software can help. But if focus is a problem and your image is soft or fuzzy, computer software can only enhance the image itself. It cannot do miracles. Maybe someday, but we aren't there yet. So its always best to start with an images that is decently focused and work at improving it from there. Since sharpness starts in the camera lets look at some things you can do there first.

IN CAMERA TRICKS:

1. Make sure you are shooting with the correct settings. Keep your ISO as low as possible. The higher the ISO the more grain will be in your photos making them appear less sharp even if they are perfectly in focus. Don't forget to check your ISO setting before shooting. Some cameras do a better job than others in low light but generally speaking the lower your light the less likely you will get a nice, clean, sharp image.

2. Secondly, make sure you have your aperture set to the appropriate setting for your subject. If you are doing a landscape keep your F-stop between 6-13. If you are doing a portrait of a group set it between 4-6. And if you are shooting a portrait of one person close up 1.4-2.8 is best. What does this have to do with the sharpness of your focus? Aperture controls the depth of field. The higher the number, the wider the depth of field, which allows for more of the photo to remain in focus. The smaller the number, the shallower the depth of field. Shallow depth of field gives you that fuzzy look for everything around the subject of your image, for example the eyes in a portrait will remain sharp if you focus on them at 1.4 but the nose and hair will be slightly out of focus and the background will be completely blurred out. Cool look for a portrait, but not for a landscape. So take note.

3. Thirdly, make sure you are shooting either fine JPG or RAW. RAW gives you the most control once you are in post-processing on your computer. It's like working with a negative. The file has not been compressed at all. There are also tools for RAW images that give you control over the temperature, focus, exposure of your images in Photoshop that don't exist for JPG's.

So let's say you have an image that has nice focus but you really want to step it up a notch or two. Go to your computer.

POST-PROCESSING TRICKS:

There are many software tools available to help you fine-tune your photos using your computer. Think of these tools as a digital darkroom, only better. There are two programs that are the most widely used. Adobe Lightroom and Adobe Photoshop. Photoshop is more expensive than Lightroom and is more powerful but it is also more complicated and takes more time to learn. Lightroom is new and is amazingly powerful for the price and ease of use. If you are a beginner, I would start there. But know that there are some things that just can't be done yet in Lightroom.

4. Sharpening your overall picture

Lightroom: Use the tool for sharpening. It is a very simple slider feature where you control the amount, radius, detail and masking. You get to see a preview of your images before applying the changes. In Lightroom 2.0 you can even select a small area within your photo for sharpening. In previous versions you could only select the entire photo. This is a great new feature because it allows you to have more control and more control is always better. More on that later.

Photoshop: Using CS2 or CS3 versions of Photoshop, the sharpening tools are located under "filter" on the top toolbar. You have several choices including; sharpen, sharpen edges, sharpen more, smart sharpen and unsharp mask. The tool you will use the most is unsharp mask. In my experience it gives the overall best control for sharpening. As in Lightroom, it allows you to control the amount of sharpening but also the radius or pixel size. The larger the radius the more difference you will see in the image. Be careful not to make it too large because your images will look doctored and fake as a result. As a general rule the radius setting is the most important so adjust that one first. When working with fine detail it is best to keep the radius quite small, for example under 1. This would be true for a portrait that is close up and you have many fine details in the hair. Too high a radius and the hair will end up looking fragmented and broken. The unsharp mask also gives you the ability to adjust the threshold. The threshold slider allows you to limit the amount of sharpness is applied to your images. The higher the number on the slider the less sharpening will be applied to your image which will avoid halos and noise as a result.

5. Sharpening part of an image

In both software applications it is possible to sharpen only part of your image. I use this most often for sharpening the focus of the eyes on a portrait. I do this in several steps and I typically use Photoshop so I will explain it from that perspective.

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Select the iris' of both eyes. You can do this using the lasso tool but be sure to set the feature at 5 pixels. This will avoid a hard line around your adjustments once they are done. After you select the first eye, hold the shift key down and select the second eye. This is an important step because this way whatever you do to adjust will be exactly the same for both eyes.
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Go to "image" on the top toolbar and select under adjustments "levels. Move the middle slider toward black slightly and then bring up the black slider until your image shows the contrast that looks best to you.
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With the eyes still selected go then to "filter" and select unsharp mask under sharpen. You have more latitude for sharpening this way than you do when you are sharpening the entire image. It is such a small area and the color is so varied a little bit of noise won't hurt the overall result. When you are done the eyes in your image will definitely pop.

6. Sharpening using other tools.

Sometimes you don't need to actually sharpen an image to bring out the detail or make your image pop. Consider these other options:
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Adjust the contrast of your image.
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Adjust the clarity of your image.
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Adjust the levels of your image
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Bump up the saturation just a bit on the color of your image.

7. The best thing to do is practice. Practice adjusting your images, and practice taking images in all different kinds of settings, using these tips and tricks. In the age of digital photography there is no risk and no loss of money if you make a mistake. You will learn from them and you will grow.

8. Here are some links with other great tips for sharpening your photos.

http://www.naturescapes.net/122004/tg1204.htm
http://www.earthboundlight.com/phototips/unsharp-mask.html
http://www.flickr.com/photos/thomashawk/2714735350/
http://www.adobe.com/products/photoshop/family/?promoid=BPDEK