If you’re a Windows user, you’ve probably noticed that some of your iPhone photos are upside down when you upload them on your Project.
The only problem is that when you hold your camera with the volume buttons pointing up, your photos will be upside down on most Windows machines.
If you rotate your iPhone, the camera sensor won’t know about it. It will simply record the image and save it to a file, letting the software on your phone do the rest. To make sure that your photos are displayed correctly, your iPhone adds information about the correct rotation of the photo to the properties of each image, which are specified in EXIF tags.
How To Solve This Problem
You can prevent any rotation issues in the future by taking your iPhone photos and videos with the volume buttons pointing down. You can also use a dedicated camera app such as 'Camera+' for all your photo needs. Unlike the iPhone’s native camera app, Camera+ actually recodes all your photos into the correct orientation.
If you already have a lot of photos that are shot upside down, it’s best to use software that knows how to deal with EXIF correctly. All Apple software falls into this category, so if you’re a Mac user, you probably haven’t even noticed this issue.
If you want to fix the orientation of your entire library at once, it’s best to do it in Picasa. Simply select all the photos you want to rotate (Ctrl+A to select all) and choose to save changes (Ctrl+S). Depending on the size of your library this may take a few minutes, but once you’re done, all your photos will be in the correct orientation forever.
Information Courtesy: Emil Pakarklis