Selection tools. Do you know what I mean? It’s that group of tools in Photoshop that selects stuff; the rectangle selection tool, the ellipse, the lasso tool, the magic wand and the smart selection tool.
You know when stuff is selected because there is a black and white dotted line around it that is flashing. It is sometimes called the marching ants, because that is what it looks like. A selection is a powerful way to change only certain areas of your image.
OK so I want to select something. I want to do it quickly accurately and when I’ve finished I don’t want anyone to know what I’ve done. Let me show you how I do that. I would like to select the monkey in the picture. I use the lasso tool and roughly draw a circle around the monkey. I can then enlarge the picture and refine the selection. My left hand hovers over the Alt key. If I 
hold the alt key down as I select, that area will be removed from the selection. If I do not have the alt key depressed, it will add to the selection. Add and Remove, I slowly change the selection so it is closer to the edge that I want. In this instance the monkey has fine hairs that stand out from his coat. I can’t trace around each of these individual hairs. So I use the magic wand to automatically trace the contour for me. Again the alt key will determine whether I am adding or subtracting from the selection.
Occasionally it all goes pear shape. I press the undo button and the try again, this time with a lower sensitivity setting on the magic wand. I usually start with a sensitivity of 25 and then turn it down to 10 and perhaps 5 if I am working with fine or low contrast detail. Eventually I have the entire image selected to my satisfaction.
Time to test my work. I hit the create a mask button in the layers dialogue. I find that my carefully traced edge is pixilated and I have missed a few areas of monkey and have included a few areas of background. I fix the ommissions in the same manner as I have outlined above. The harsh pixilated border needs to be softened. In this case I blur the mask by a small amount, say 2 to 3 pixels.
Now I have the monkey selected I can do things to it. I could cut it out to add to a different background. This however isn’t my intention. I want to sharpen the monkey and blur the background. I use different contrast and colour settings for monkey and background. The effect simulates narrow depth of field. The final product is the large picture at the top of this page. The transition between sharpened and blurred areas looks natural. All of the hairs look sharp and there is no cuff of pixilated background around the edges. That hard work has paid off.
A few pointers about using selection tools:
- There are 4 modes for selecting – “New”, “Add to”, “Subtract from” and “Intersect with”. Experiment and see how each mode behaves. There is an indicator in the top left corner in the options bar to inform you which mode you are in.
- You can select how much to feather your selection in the options bar. I usually select 0 as I can always feather the border later from the “modify” dialogue in the “Selection” menu. The amount of feathering required depends upon how sharply focused your subject is. I usually find a little bit of feathering helps.
- It is important to adjust the “sensitivity” of the magic wand tool (options bar) if you are getting too much or too little selected. Also you can uncheck the “contiguous” box if you want to select lots of unconnected areas, like the blue sky between the branches of a tree.
- Remember you can invert your selection. This helps if your subject is very complex. For instance if you want to select a bird in a blue sky. Select the sky with the magic wand tool, then use the “invert” command in the “selection” menu to deselect the sky and select the bird. Much quicker.
- You can turn a selection into a mask. You can turn a mask into a selection. Sometimes creating a mask is a handy way to save a selection for later use while you go and do other tasks.
- The Quick selection tool (in the same tool palate as the magic wand) offers another quicker way to achieve the selection. I find however that it may not offer as much control in the areas of fine detail like the hairs as mentioned above.
Camera Clips 