Why would some JPEG photos come out of the same camera with different pixel dimensions? I have kids taking photos and DopBoxing them to me. I'm pretty sure they are not cropping them, they don't have the software.
Thanks Johan. The camera was set to shoot Large JPEGs and all the images the students downloaded and sent me were roughly 5000 pixels longest side except one which was only about 800 longest side. I don't think their camera allows for in-camera cropping and I doubt they would know how to do that. So it's a mystery why just one image would be so small. And of course it's a great image so the low res is a problem. I'm wondering whether really poor internet speed could cause one file to 'corrupt' like this?
In that case it is almost certainly the camera settings. Some cameras can combine certain settings, so for example when you shoot with aperture priority the camera shoots in Large JPEG, but when you switch to full auto the camera also chooses another size JPEG, if those settings were stored as a specific user setting.