I'm not sure I quite follow, MikeThrough the viewfinder I see things in f/1.8 and I get accustomed to things being at f/1.8. Then one can only get disappointed when the closed-down shots develop on the back screen. And when one suddenly uses the aperture preview button things are always so dim.
Kind of wish the viewing aperture could be changed using the menus from lens' maximum to f/2.8 or even f/4 to see more of the world.
The viewfinder shows the view at the maximum aperture of the lens attached (*). It was actually a significant step forward that one could focus and set the exposure with the aperture wide open.
But the preview button shows the effect of the selected aperture.
(*) never more than f/2.8 if I remember correctly, even when the lens is f/1.4 for instance.
Try attaching a zoom lens that is only f/5.6 on the long end and set the zoom to the long end.
It's quite dim and not exactly pleasant. In fact, it will be harder to see the world.