[raymo]

With a DSLR attached directly to the focuser without an eyepiece, you can
see what the camera is seeing by either looking through the camera's
viewfinder, or using the LCD screen on the back of the camera, but unless you are looking at something bright like the moon, the view will be quite dim. If you are using an up market compact you may be able to see what it is seeing by using
the LCD screen. As budget compact viewfinders don't look through the lens, you would have to move the camera out of the way in order to look through the eyepiece.
raymo