I am going to buy my first iMac. I'm in doubt to go for the 512GB SSD or the 1TB SSD. How much space is needed for the OS? Is a scratch disk part of this (I am comming from windows ). I will be using it primaraly for photo editing (Capture One/ Adobe suite). Perhaps in the future I wil be playing with Final Cut pro/ Logic Pro x. So far I,ve selected the 3,7 GHz 6 core I5, Vega 48, 512GB or 1TB SSD and extra ram will be installed later.