How to get full size exports in Photos?
I find that when I select a photo in Apple Photos on my iMac and then try to export it, it is exported at a low resolution, typically 1024 x 768 pixels, whereas the info for the (edited) picture in Photos shows a much larger size, typically of the order of 3000 pixels (depending of course on the original). Searching here for this problem, I see that some people see a 'size' option in the 'export' dialog box, but I don't see this option, nor do I see an option for JPEG quality. The only way I can get the full resolution is to open the file in an external editor - when I do that, Photos transfers the full size picture to the editor. I don't want to do this, as I am quite happy with the editing features of Photos itself.
Can anyone explain what's happening and tell me how to get the right dialog?
iMac 21.5", macOS 10.13