Many iPhone and iPad users find that their photos are sometimes turned sideways when they post them on our forum and other places on the Web. This is a glitch in the Apple iOS system that saves the image in a non-standard way. The orientation is saved as a bit of code within the image file. Sometimes the image will even have the orientation instructions recorded in two conflicting ways in the same image.
Might look just like you took it on your iOS mobile device or Mac, but looks sideways when you email it or post it on the Web.
Try Speedracer's method shown 2 post below in this thread.
Last edited by Oldgas; Wed Feb 20 2019 09:52 AM. Reason: Edit to update the new situation after 2018 upgrade