There are times when you find that the photos you take suffer from distortion and that straight lines appear curved when they should not be. While this technique will not eliminate the need for a good tilt-shift lens, you may find that it is very helpful and easy to do when you just need some simple straightening around the edges. Before we get into the technique, here are a couple of sample image that we are going to straighten. Your may recognize them from the series that I did for James and NWP last year:
Here is also the shot that James took which started this conversation off on how to fix the edges of an image. It is of the New York City skyline at sunrise.
OK. Now, let's work on straightening these images!
1. Open the image in Photoshop.
2. In the "View" dropdown menu, go down to "Show" over to "Grid" and click on Grid,
3. In the Layer dropdown menu select “Duplicate Layer”
4. Now over to the Right where the History, Layers, Channels and Paths options are click on Layers so that you see both Layers, Background and Background Copy - Click the Background Layer to make it the active layer,
5. Go to the Image dropdown menu and select Canvas Size - In the Canvas Size Popup menu, increase the width by approximately one quarter of the height for this particular image. Leave the Anchor in the middle so it will add width in both directions. No need to mess with the height for this one but you could also do height or expand either way by which of the 9 squares you select, ( I think I went from 13.3 to 15 inches on the low res version)
6. Then click “OK.” You should now have additional space to work in on both ends of the canvas. Your new canvas' will look like this:
7. Go to the Right Hand Layers Menu again and click the Background copy to make it, the top layer, active, Now is when the work begins!
8. Go to the “Edit” dropdown menu, go down to “Transform” and over to “Distort”
9. You will now have little squares at the corners and midpoints. Grab the left top corner square and drag it carefully along the top grid line until the building edges on the left are closely aligned with the vertical grid lines and release. The vertical lines may appear pixilated during this exercise but if they do it’s only temporary, now go to the right top corner and drag the right top square until the Bridge Tower appears to align with the vertical grid lines and release the mouse. It might not take quite as much as the other side.
10. Now check the left side again to see if another minor adjustment is necessary after stretching the other side, then recheck how the right side appears. Now hit “Enter” and the squares will disappear and the pixilation should be gone. You can redo the previous Edit sequence if it doesn’t yet appear quite right to you. On a stitched image, it may still have some built-in distortion at the stitches but if so they should be minor.
11. Go to the “Layer” dropdown menu at the top and select “Flatten Image.” You should now have a top-heavy trapezoidal image with extra canvas at both ends. 3rd image below.
12. At this point you should turn off the grid using the View dropdown by going down to Show and then over to Grid and unchecking it with a click. You want to do this so that you don’t accidentally do the next step of cropping on a grid line as it will try to snap to grid lines.
13. Take your Rectangular Marquee Tool, second down on the left hand tool bar, and set your lower left corner and drag it diagonally across your image until you are at a point on the upper right that aligns with the lower right corner.
14. Go to the “Image” dropdown menu and click “Crop”, you now have the middle image below.
15. Before you do anything else “Save As” IMAGENAMEadj.
Then you are finished. Here are the images again - now with before and after results! Take a good look at the edges of the frames - particularly around the telephone poles. You will see how this simple technique really can change the look of your images.
Here is another example:
Thanks again to Richard Strange for sharing this technique with us. Just a reminder that the content and photos are (c) 2012, Richard Strange (except the photo of the NY Skyline, of course! That is owned by James Morrissey). They have been licensed to NWP for the purpose of this article.