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Image Sharpening

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Image sharpening is a powerful tool for emphasizing texture and drawing viewer focus. it works by exaggerating the brightness difference along edges in an image. the key to effective sharpening is walking the delicate balance between making edges appear sufficiently pronounced, while also minimizing visible under and overshoots (called “sharpening halos”). Fortunately most software setting are reasonably standardized.
How it Works
Controls the overall strength of the sharpening effect, and is usually listed as a percentage. A good starting point is often a value of 100%
Controls the size of the edges you wish to enhance, where a smaller radius enhances smaller scale detail. You’ll usually want a radius setting that is comparable to the size of the smallest detail in your image
Controls the relative sharpening of fine versus coarse detail (within a given radius value), in addition to affecting the overall strength of sharpening. Higher values emphasize fine detail, but also increase the overall sharpening effect. You will therefore likeliness to adjust this setting in conjunction with the amount/percent setting.

Controls the minimum brightness change that will be sharpened. This can be used to sharpen more pronounced edges, while leaving subtle edges untouched. It’s especially useful to avoid sharpening noise.

Sharpening Workflow

There are three types/stages of sharpening.

Stage 1 Capture sharpening

Capture sharpening is usually applied during the RAW development process. This can occur automatically in your camera,whine saves the image as a jpeg, or it can occur manually using RAW software on your computer(such as adobe camera raw,lightroom or any other RAW software that may have came with your camera. Generally, well-focused images will require a sharpening radius of 1.0 or less, while slightly out of focus images may require sharpening  radius of 1.0 or greater. Regardless, capture sharpening  rarely needs a radius  greater than 2.0 pixels

Stage 2 Creative sharpening

While creative sharpening can be thought of as any sharpening which is performed between capture and output sharpening, its most common use is to selectively sharpen regions of a photograph. This can be done to avoid noise or, to draw attention to specific subjects. The key to perform such selective sharpening is the creation of mask. This mask may need to be manually created. Alternatively, sometimes the best technique for creative sharpening is to add a blur, making the subject appear sharper – while avoiding over-sharpening. It can also lessen the impact of a distracting background.

stage 3 Output sharpening

After capture and creative sharpening, an image should look nice and sharp-on screen. however ,this usually is not enough to produce a sharp print. Output sharpening requires a leap of faith, on screen viewing will not provide the correct amount for the type of paper,printer, or viewing distance or, resolution of the print. Good start is the program software settings,or trial and error.

  1. EPC Admin says:

    Good followup to your presentation, Mike.

    I know I keep promoting a sharpening plugin called ‘Pixel Genius PhotoKit Sharpener’, even though I don’t hold any shares in the company.

    It’s one of those products that just works and I’ve been using for over a decade now.

    It is absolutely an indispensable tools in my workflow.

    As with any tool, the information you present here goes a long way toward getting the most out of it. Photokit just makes the application much easier and and the process can become fairly automated.

    More info can be found here:

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