I wanted to expound a bit on the correct answer as of 4.11 (I didn’t look at code for prior versions).
Every time a level ticks, it iterates through components and tells them to update their rendering.
The SceneCaptureComponent2D has this check before updating its rendering:
if (World && World->Scene && IsVisible())
So you can see that whether or not it is rendered depends on the visibility of the component. Using Hidden in Game and/or Visibility directly will correctly disable rendering on the capture component.