PixelGenius PhotoKit Sharpener

This application comes either as a stand alone or a Photoshop plug in. I've only used the plug-in version. It works by breaking the sharpening process down into three stages - capture sharpening, creative sharpening and output sharpening. The capture and output stages are adjustable to conform with the method of capture, output device and print resolution. The creative stage employs several different sharpeining techniques which you can choose depending on suitability to the image. I recommend you check Pixel Genius' website for a fuller description.

However I can confirm that the application works extremely well. Because it untilises Photoshop's layers, it does not permanently alter the original image and you can try out various types of creative sharpening at the same time to compare the effects and choose the best one for your image. Another great advantage is that you have the option to use the brush tool to 'paint' sharpness onto specific areas of an image.

The learning curve is maybe a little steep and so this is really an application for advanced amateurs/pros. However, if you know your way around Photoshop and its layers, then Photokit Sharpener gives a far superior result than just using the USM filter and is a very worthwhile investment. For what it does, it's a bargain!

Total flexibility of sharpening process
Can be used as a Photoshop plug in
Superior results
Uses layers so doesn't affect original image

File sizes can get huge!
A bit of a resource hog, needs plenty of RAM (min 1gb) and a fast(ish) chip to go quickly.

Photoshop's USM filter.

Not needed.