- Image sharpening is an effect applied to digital images to give them a sharper appearance. Almost all lenses can benefit from at least a small amount of sharpening. Sharpening is applied in-camera to JPEG images at a level specified by the photographer or at the default set by the camera manufacturer. Lightroom automatically applies some sharpening to images unless it is instructed not to. For further sharpening, there are Photoshop techniques and filters like Unsharp Mask and Smart Sharpen to do the job. Sharpening works best on images whose blur did not stem from camera shake or drastically missed focus, though minor camera shake or slightly out-of-focus shots can also be fixed with sharpening.