Sometimes we may not have framed an image exactly perfectly and we may want to rotate it. We can do this easily.

This image of Venus was shot with the camera oriented in right ascension and declination, so Venus is not correctly aligned with the horizon and the bottom of the frame.

Crescent Venus not aligned correctly to the horizon.

There are two ways to rotate an image in Photoshop. We can make a selection of just the object inside the frame and rotate it, or we can rotate the entire image.

• Rotate a Selection

  • First click on the default background colors of black and white in the bottom of the tool palette. Make sure the background color is set to black.

  • Make a selection with the rectangular marquee tool.

  • Under the Edit pull-down menu, select Transform > Rotate.

  • The rectangular selection will transform to a box with little square corners and the cursor will change to a curved two-headed arrow.

    Photoshop's selection rotation box.

    
    

  • Click and drag the cursor to rotate the image.

  • Hit enter or click the check mark on the option bar to apply the rotation.

  • Use Edit > Undo or Ctrl Z to undo the rotation.

• Rotate the Entire Image

  • Under the Image pull-down menu, select Image Rotation > Arbitrary

  • Under Image Rotation you can also select 180 degrees, 90 degrees clockwise, or 90 degrees counter-clockwise.

    Photoshop's arbitrary rotation box.

    
    

  • Click ok to apply the rotation to the image.

  • You may have to experiment with different values for the rotation by trial and error.

  • An arbitrary angle can also be input to rotate the image, but it will have to be cropped again to remove empty borders that are created.

  • Use Edit > Undo or Ctrl Z to undo the rotation.

The result of the rotation is seen below.

Crescent Venus rotated and aligned correctly to the horizon.