preview size too large for 720hd option

digitalzero

hey there you all im trying to create a mock trailer for my video game but i would like for it to be under the 720hd option! however when i am attempting to put actors outside of the scene so that theyre not visible but the grey area that i have to keep them outside of the scene i cannot see... any way to make the preview scene smaller (without changing the dimensions) so that i can make the trailer