If there is one sharpening technique that works for most images with detail it will be this one I am about to explain to you. What I like about this method is that it is fast and does not add any noise to the smooth sections of the image.

This method works best where you have a lot of sharp edges such as grass, bricks (like the sample below), close-up of sand and deserts etc. Do not use it on smooth surfaces such as painted walls, clouds, faces etc.

Here is the method (I only know the windows commands in Photoshop CC):

  1. Open a jpg image in RGB mode (That is important, it should not be CMYK or LAB mode)
  2. Press F7 to see your layers
  3. Press CTRL-J  to make a duplicate layer of the image
  4. With the top layer highlighted click on the Channels tab (if not there, on the main menu click <Window> and select <Channels>
  5. Select the RED channel, all the others will be deselected and the image will go light gray. The shortcut is CTRL-1.
  6. On the main menu select <Filter> and then highlight <Sharpen> and click <Unsharp Mask>.
  7. Ok, we are going to radical here, in the Amount field type a very high number: 400
  8. In the Radius field: 0.4 (A good rule of thumb, divide the Amount by 1000 to get the initial Radius value, after that you can play around with values to get the effect you want.)
  9. The Threshold stays at 0.
  10. Click <OK>
  11. Click the <Layers> tab
  12. Just to the left of <Opacity> you will see a combo box with “Normal” on it.  Click it and scroll down to the last option “Luminosity” and select it. So make sure the “Normal” has changed to “Luminosity”. This is crucial otherwise your image will have RED casting.
  13. At this moment your image is still gray, select the bottom layer to see your results.
  14. To see the effect click on the little eye to the left of the thumbnail on the top layer. You can click it on and then off quickly in succession to see the effect better.
  15. Focus on the detail parts such as edges of bricks, hair or detail of clothing.

That is it.  You can use the RED channel or GREEN channel, never the BLUE since it will create too much noise.  In about 90% of cases you will use the RED channel, however, with the image sample below I used the GREEN as well with much greater effect.

Three images, A not sharpened, B sharpened in the RED channel and on a separate luminosity channel and C using the GREEN channel also on a separate luminosity channel. Image shown at 100% magnification taken on a Nikon D200 with 35mm DX lens at f11,

I prefer “B” since over sharpening sometimes can have negative effects and it does become obvious to even the layman.

This methods with key commands will/should also work in Photoshop CS3.  I don’t think it can be done in Photoshop Elements since it does not have the separate channel options.

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