Monday, April 30, 2012

Photoshop Tutorial: Adding Canvas

Cara Cara in flight, Viera Wetlands
| f/7.1 | ISO 320 | 700 mm
It's rare that I capture a bird in flight and am happy with the composition of the image. Most of the time, they are right in the middle of the image (that's where I have my autofocus sensor). And if they were close, then I probably didn't leave enough room for them to "fly into". In this tutorial, I'll show you what I do to fix this problem.

Below is the original image. Disregard the fact that it's underexposed and not color corrected (we'll fix that in a later post). Notice, however, that the image could use a little more room on the left and possibly the bottom.

The first step is to add blank canvas to the left and bottom of the image. To do this, go to the Image drop-down menu and select Canvas Size. The dialog shown below will pop up:
The top of the dialog box will tell you the current size of the image. In this case, my image is 4288 x 2848 pixels (this might show up in inches or cm). The middle of the dialog box asks you to input how much canvas you want to add to the width and to the height. In this case, I decided to add 1000 px to the width and height. I always add a little more than I think, since I can always come back and crop some out if I don't want it. Make sure that you have the relative box checked - this tells photoshop to add the specified number of pixels (or inches/cm/mm) to your image. Underneath the checkbox is the "Anchor" which tells Photoshop in what direction you want to add the canvas. For this case, I only wanted to add to the bottom and left sides of the image. And finally, all the way at the bottom you can choose what color you want to use to add the extension. I usually choose white, but it doesn't matter since we will be filling this canvas in with something else later.

*A quick note: if you tell Photoshop that you want to add 1000 px to the height and you choose to add to both the bottom and top of the image, then Photoshop will add 500 px to the top and 500 px to the bottom. I originally thought it would add 1000 px to both the top and bottom - not the case. 

Once you click OK, you will see that your image now has a large white border around the sides that you added canvas to. The next step is to fill these in with something appropriate. I have to mention that there are MANY ways to fill this in, but in this post I'll discuss my favorite (and easiest) way. Using the rectangular marquee tool (press the letter M to select the tool), select the white border that you want to fill in. I always select a little of the background that I want as this will help Photoshop see what I want to fill it in with. For this case, you want to make sure that you only select a little of the background and no part of the bird - otherwise Photoshop will do some weird things when it fills in the white. Below you can see the selection that I made.
The final step is to fill this area in with something appropriate. Like I mentioned, there are quite a few ways to do this, but I'll let photoshop do all of the thinking and use Content Aware Fill. With the area of interest selected, go to the Edit drop down menu and select Fill. Under contents, make sure that "Content Aware" is selected. Then click OK. Your white area should now be filled with blue sky!
Since we also have to fill the bottom of the frame, I'll show you another method to fill in the blank canvas. Use the eyedropper tool (keyboard shortcut 'i') and click on a part of the image that resembles what you want to use to paint in to the blank canvas. Notice that your color swatch (on the bottom left) will now have this color as one of the defaults. Select the brush tool (keyboard shortcut 'B') and in the tool settings (top bar), make sure to select a soft edged brush (Hardness = 0). With the Opacity and Flow set to 100%, start to paint over the white canvas. That's it. Note that this method only works if the area that you are filling in is fairly uniform.
Using the brush tool to fill in the bottom portion of the image
Once all of the added canvas is filled, you can crop to whatever size and aspect ratio you want!

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