If you want to handle many pictures, it is useful to have a SystemDialog helping you. I do it this way:
First I define a start directory once:
startdirectory = "\\\\Whisper\\c\\Users\\ingol\\OneDrive\\Foton";
Then I open a file window, where I can choose a number of images:
filelist =
Flatten[{SystemDialogInput["FileOpen", startdirectory]}]; startdirectory = FileNameDrop[filelist[[1]]] <> "\\";
Thus I obtain a list of pictures, and if I open the file window again, it will open with the last directory used.