iMac>iCloud>Multiple accounts?

Hi all,

Just upgraded to a new 21 inch iMac after a number of years, so still getting acclimated to the new OS X and updated features (last OS X I was using up till now was Leopard).

Anyways, on to my question. My wife and I have iPhones, separate iCloud accounts, but share our iMac. For purposes of photos, how can we sync both accounts to update with iPhoto? Does it allow for multiple accounts to be synced with it? Or are we going to have to combine our iCloud accounts?

I tried to plug in either of the iPhones to import the pictures directly to iPhoto, but it doesn't allow me. It only shows me a handful of photos as an option to import as opposed to the entire library on the iPhone.

Thanks