try to standardize the website " large " print size ( the image after it is clicked on )
i have a large monitor and portrait oriented images i don't bother to scroll down if they don't fit on my screen.
i don't think i am alone ... the web-image is just to give an idea of what the final print looks like,
it doesn't have to be gigantic, just big enough to see ...
i know someone who insists on having HUGE scans on his website, he insists people want to see gigantic scans to see the "quality" ...
no yours aren't anywhere as big as his ( and that's good! )
... but just the same easy make the scans big enough to see the image easily on the screen, without scrolling .. scrolling is a PITA