eyepiece projection

Dumb question perhaps, but when you do eyepiece projection
photography, can you focus by viewing at the eyepiece then mount the
rest of the hardware to take the photograph? I just focus at the
camera, but it seems that once the telescope is focused, the distance
between the eyepiece and the film plane is just altering
magnification. My gut feeling is no, because when you view at the
eyepiece, you are also compensating for your eyesight.