You can find the answer to your question by going outside on a moonless night. To keep everything fair and right, choose a night when there are no clouds. Make sure you are near no sources of artificial light. If you choose a summer night then you need to be sure you are getting full darkness (e.g. I live at 55 deg north and June nights don't get fully dark for a week or so around midsummer).

You'll find, all being well, that starlight is just about sufficient to make out shapes. If you hold your hand against the sky, you'll see a silhouette.

This gives a slightly false impression of what deep space might be like though, because we are in the thick of a bright galaxy. It's a good bit less bright in the huge spaces between galaxies.