Max upload size for each photo on One Page Link is 15mb, which is actually very high. Standard file size for a Promo Shot is approx 3-6mb, this is plenty for a high res photo at 300dpi for standard print applications. Good for quality, good for ease of use for all involved.
Your pics can technically be up to 15mb on OPL, but some photographers supply artists & teams with large files over 15mb, in which case you need to compress your imagery. If you're unable to get lower file sizes suppied, here is a website where you can compress your images.
note - we have no affiliation with this service.
We found the default settings to work well, you can also adjust these settings if you’re unhappy with the compression.