Why sharpen images? Some images you take may need a little help, for two main reasons, first your camera may not be able to capture as many pixels as you need for a really sharp picture and secondly your camera handling is not quite as good as it could be - i.e. there is a bit of camera shake evident. Bad camera shake is generally not going to be helped by trying to use the Sharpen filter - you will just end up introducing artifacts into the image if you overdue it's use because...
What does the Sharpen filter do?
Put simply, the filter looks for differences between pixels and in particular
those groups of pixels that might define edges in the picture, then it emphasises the difference between the pixels to create and impression of more definition or 'sharpness'. It is just that, an 'impression' - not a substitute for the real thing. Avoid the temptation just to keep applying the Sharpen or Sharpen More filters repeatedly - it will not necessarily have the desired effect!
First have a look at straightforward sharpening. Open the Deer image.
This is already a nicely taken picture, but it will point out well how sharpening affects an image, also it is a good example of a type of image that benefits from sharpening as it has elements such as fur, hair and grass that provide something for the filter to act upon. To sharpen the image, just use the menu command: FILTER > SHARPEN > SHARPEN.
Use it a couple of times then use FILE > SAVE AS to save the changed image with a new file name. Then open the original deer image again and compare them side by side.
Sharpening works best with black and white images. This is a technique used commonly in portrait photography and you might want to try it yourself. Convert the original deer image to black and white by using the command IMAGE > MODE > GREYSCALE - then save it with a new name. Now use the Sharpen command again a couple of times on the grayscale image and use FILE > SAVE AS to save again with another new name.
Compare the colour and grayscale originals and sharpened images. Make an evidence sheet (or two) with all four images on.