Chosen Solution
A friend has this camera and so do I. We both have the image size set on RAW and L. My photos have a high resolution of 6000 x 4000 and hers are at 640x427. We cannot figure out why her photos are so small. Would this be a camera defect?
That resolution isn’t even possible with that camera. However, 640x424 is a supported video resolution. Are you sure your not looking at the video setting? If not, what is the resolution of your pictures based on what your computer says? Good luck.