Photography Tutorial: Sharpening

Photography Tutorial: Sharpening

What is Sharpening

The unfortunate truth about all digital recording/capturing technologies is that they convert analog signals into samples of the original. The frequency of how often the signal is sampled determines how well the original analog signal will be when digitally reproduced. While modern devices have high sampling rates of 12 bits for each of the RGB (red, green, blue) spectrum colors, this number is actually quite coarse, or crude compared to reality. 

The real world is comprised of infinite numbers of colours and shades, to observe this one has to only look around them, at the sky, forest, water. You will see enumerable shades and tints of the same color; so while capturing a large enough portion of this information to create a (in our eyes) high resolution photograph, the digital recreation pails in comparison to the real thing. 

This creates the problem of an inherent fuzziness or noise in any digital recording or abstraction, due to it being only a fragment of information of the original. So in order to combat this, we employ a technique called sharpening. This enhances the photograph and makes it look "sharp", "in focus", and gives a higher clarity to the photograph. This is also one of the major differences between a professional photographer's photographs and a amateur or beginner's.

So with that lets show you how to sharpen like a pro!

How to Sharpen

While there are enumerable ways to sharpen your photos, and different schools of thought for each one,  a good way to sharpen that works for many different photograph types, is the High Pass filter. The High Pass Filter works by sharpening edges only, leaving non-edges unsharpened. This is the goal of sharpening and what all the various other sharpening filters aim to help you do.

Now on to it!

Step 1: Open Photoshop

Step 2: Open your image

Step 3: Duplicate the original or background layer

Duplicate the original layer (also known as the Background layer in photoshop)

To duplicate the background layer, select it from the layers panel and press the keys CTRL & J at the same time, if you are on a mac press Command & J. This will create a duplicate of the layer. 

Another option is to right click on the background layer and select "Duplicate Layer"

Step 4: Change the blending mode of the new layer to Overlay

The High Pass filter, when ran, turns all non-edge surfaces into a neutral grey colour, this may seem off-putting at first however we made a duplicate layer for this very reason. Go back to the layers panel and where you see a drop-down menu with "Normal" in it. Change this to "Overlay". Switching the panel to "Overlay" causes photoshop to only apply the non-neutral grey areas from the selected layer to the layer below. This means we will only see the edges of our original photograph sharpened.

One side effect right now is that your photograph will appear to have a large amount of contrast, this is to be expected and will only be temporary.

Step 5: Apply the High Pass filter

Now that you've accomplished the previous steps, go to the "Filter" menu at the top of the screen and choose "Other" and then "High Pass".

The High Pass filter is fairly simple to use, there is only one slider to increase or decrease the amount of the filter applied. Checking the "Preview" option on the side will show you your changes on your photo as your move the slider. 

To sharpen with the High Pass filter, start with a low radius value around 1-2 pixels and drag the filter to the right or to the left. If you begin to see halos or glowing around the edges, you have sharpened too much, decrease the radius slider. We used <--> as our value, yours will differ, play with it to find what works for you. How much you sharpen will very from photo to photo, so do not expect your values to always be the same. 

(Optional) Step 6: Fine tune the sharpening.

You can fine tune your sharpening even more so by changing the blending modes, changing the blend to Hard Light or to Soft Light will adjust the intensity of the sharpened layer. Hard Light will increase the sharpening and Soft Light will decrease it. This is at your discretion, try both to see the effects.

So thats it folks! We hope you enjoyed this tutorial and found it helpful. We look forward to starting on next weeks tutorial and creating something useful as always.

Happy Shooting!

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