When it comes to sharpening I find that the vast majority of people know very little about it, why they should do it and how they should do it. I also see that many images if they do get sharpened actually wind up being ‘over-sharpened’. There is actually quite a bit to know and there isn't exactly one solution for all photos. The following are some guides to get you through a simple and necessary process that should be done to all files
What is sharpening?
Sharpening adds contrast to edges. Anytime we add contrast to an image our brain interprets it as ‘sharper’. All sharpening tools across all program work exactly this way, the flexibility that you get with each will vary.
What images should be sharpened? The first thing to consider with sharpening is JPEG vs. RAW files.
All JPEG files are sharpened to a certain degree in camera. This is controlled in the ‘picture style’ menu. When we shoot JPEG files the camera will choose a picture style, generally ‘standard’. These are found in the menu and are not to be confused with ‘scene modes”. When you look into the picture style menu you will see that there a variety of styles to choose from depending on your camera.
A picture style controls 4 specific things, Tone, Saturation, Contrast and Sharpening. Each picture style has varying degrees of each depending on the ‘style’ chosen. For example a Portrait picture style would give more natural tone, Landscape more vivid color and sharpness., etc.
RAW files are not sharpened in camera and therefore should be always be sharpened.
How should images be sharpened?
There are a variety of software programs that can be used for sharpening images post-process. Keep in mind that images should be sharpened based on what their final output will be regarding size and resolution. high resolution images of 300 or more dpi will take more sharpening. low resolution images of 72dpi for web will require less sharpening.
Images should be sharpened more or less depending what it is a photograph of. photos of people should be sharpened less images of landscape, flowers etc should be sharpened more use selective sharpening with layers and layer masking in photoshop for sharpening people.
What is the best software program to use?
Lightroom
For general sharpening I personally like to use Lightroom, mostly because I am already there and I find that the sliders are very straight forward to use. I would only go to Photoshop if I need to do sharpening with a layer mask like in a portrait.
After you have edited the image in the Develop Module in Lightroom, scroll down to the Detail dialog box.
You will see a thumbnail that is at 100%, also click on your image to put it at 100% view also. This is the best way to sharpen so you can see how much you are sharpening.
Amount-as you move the slider to the right the amount of contrast on the edges increases. i usually find that i will for most images use about 50-70. Radius-how far away from the center of a pixel is the sharpening effect. Use smaller radius for more natural looking images, 1.0 or higher for a guarder edgier looking file. Detail-Fine tunes the sharpening. Focuses on the finer textures and edges of the image. Masking-Hold Option key on mac and Alt on PC and move slider to right, the areas in white are sharpened whereas areas appearing in black no sharpening is taking effect.
Photoshop
Use Photoshop to apply Unsharp Mask filter on a background layer and apply a layer bask and brush in areas that you would like sharpened. The main difference between sharpening in Lightroom versus Photoshop is that you can do selective sharpening in Photoshop.