101 Photoshop Tips and Tricks - #001 ...

001 Sharpening - The High-pass Filter Way

Introduction

Sharpening is a much contested topic, and one that if you have read any photography book, magazine or online forum you will see this being discussed. I am not going to add anything to the debate, it is something that a purist will say you shouldn't use and others say you should.  Sharpening will not make your out of focus photo any clearer.  

Which gets us to English semantics, is sharper and clearer the same thing.  Like any Hollywood movie involving time travel, there are to many experts and so many holes in the explanation it is just better to say, sharpening is good most of the time.

One of my favorite sharpening methods is to use the high-pass filter, it creates an image much like an embossed copper rendering.

The original

Take this photo, one that I took a little earlier today in the garden.  It is a macro bee, and looks pretty sharp (and clear) (resizing it down to 800x800 will change the sharpness anyway, but lets not get into that discussion)

Assuming I like the colours, contrast and everything else, I have made all my adjustments in lighroom and then open it for editing in photoshop.  In this case I am using CS4. (I shoot in RAW by the way, in case anyone is wondering)

Photoshop

Creating Layers

Having opened the photo in Photoshop I create three duplicate layers. Right click on the background later, and select duplicate later, or use the keyboard sort cut <CTRL + J> (I think it is <command + J> on the mac)

Having created three layers, I rename them 1px, 2px, and 3px

Applying High-pass Filter

Select a layer to work with, in this case I have selected the 3px layer, and then find the high-pass filter, it is under Filter -> Other -> High Pass

Select a pixel radius of 3.0

Press OK to apply it, this will turn your image all grey, and ugly looking (or artistic, and you might like it)

Hide your layer by clicking on the layer hide (ie the little eye on the layer)

Repeat these steps for 1 and 2 pixel layers.

Recap

So now you have 3 invisible layers, with three different levels of high-pass filter applied to them.  These being 1, 2 and 3 pixel radius levels.  Once you get used to this method of sharpening, you will not need to apply all three types, you will get a feel for the amount you need to add, and will be able to just create the one duplicated layer with high-pass filter applied.  Though for the sake of this tutorial I have made three.

Layer Blend Option

This is where the magic starts (well not really magic, it is what the software was designed to do).

1. Make your 3px layer visible.
2. Change the blend mode to one of the light ones. I use Soft Light, or Vivid Light mostly.  For this example use soft light.
3. Toggle the layer on and off, and see the photo's sharpness pop before your eyes.

You might be impressed by how much sharper your photo looks at 3px that you might be content to stop here.  Sharpening is something that should be done in moderation.  The more you sharpen, the less natural it looks, so repeat the above steps with 1px and 2px.  

So pick a blend option you like, 1, 2 or 3 px, and delete the other layers.  Also, don't forget the opacity slider, you don't have to apply 100%. You might think that 1px is too little, and 2px is too much, so pick 2px and reduce the opacity.

The Final Product

So now that you are happy with your amount of sharpening, you can flatten the image, and save it.

For the sake of this tutorial I chose 3px to demonstrate the difference it makes.  In reality I would have picked 1px, just to get it a little boost.

Before	After

Looking at the two in the box, is a little hard to see the different, click on each of them, and you will see a larger version of the photo.

Hope you enjoyed this tip.  Feel free to donate to my new camera fund.  Any donation welcome, but I think the minimum is about 35c, anything less, and paypal takes it as fees.