Today’s Question: At the end of your answer about setting a camera to automatically rotate photos that are captured in horizontal versus vertical orientation, I noticed that you said that “rotation [would be] generally not required”. Why would you ever need to rotate an image if the camera was set for automatic rotation?
Tim’s Quick Answer: While just about every camera includes a sensor that determines the orientation at the camera at the time of capture, that feature can be turned off and it may also not always provide the intended result depending on how the camera was held.
More Detail: If the option to apply automatic rotation to captured photos is turned off, your photos will obviously not be rotated based on how you were holding the camera. That means that horizontal photos will still appear horizontal, but also that vertical photos will appear horizontal as well rather than vertical.
Even with the option enabled to automatically rotate photos, however, the camera won’t always get the rotation right.
For example, if you hold the camera at about a 45-degree angle, you would have intended the captured photo to appear either horizontally or vertically. However, with the camera held at a 45-degree angle there is a certain amount of ambiguity about what you intended, and so there is about a 50% chance that the orientation of the photo won’t match your intent.
Similarly, you may find yourself in the unusual situation where your camera is held upside down. This is admittedly rare, but I have found myself in this situation a few times. Interestingly enough, many cameras don’t accurately detect when they are upside down, and so the resulting photos will not have the intended orientation.
The point is that in some situations, even when your camera is properly configured for automatic rotation of photos, you may find that you want to rotate the photos to a different orientation later. Fortunately, that rotation is easy to apply regardless of which software you’re using to manage and optimize your photos.