Ideal number of rows per page for pagination? [on hold]

One of our developers has just designed a footer pagination toolbar for a table of photos 300px by 300px each, looking roughly like this, albeit with rounded rectangles around each number:

< 32 33 34 35 36 37 38 >

It’s currently set to show 6 photos per page, which means the images take up basically the whole visible screen in a desktop without scrolling down.

Originally we planned to have around 24 images per page so the user could scroll down before they saw the pagination toolbar.

My question is, what is best practice regarding number of items per page? Should we make it that the user doesn’t have to ever scroll down? Or do users prefer not to have to click the pagination toolbar so often? If so how far should we make them scroll down? 5 screen-fulls? 10?

We can assume that all images load pretty fast so can ignore that load time aspect.