Don't worry about it. People can get a little miffed in the gallery when stuff gets pushed off the main page too quickly but they'll get over it. If it were me, I'd actually limit it to one image per day per person. Unless there is really some kind of coherent series of images which must be posted together (which is once in a blue moon), I see no need to post more than one image per day. There's too much being posted anyway - too many negative scans etc.