I have to make a photo artwork of 8 meters by 3,56 meters. I am looking for pictures on shutter stock to work with, but I can only find images of about 50/80 cm high / 300 dpi. (I will work them into a kind of 'collage', so I'm not looking for just one picture).
I read somewhere that you can scale these kind of pictures as much as you want, for a billboard for example, but this will be for a wall which will NOT be seen from distance, but from up close.
So my question is, how much can I scale up the pictures without losing (noticeable) quality?
Thank you very much in advance!!