I have been "in the dark" (no pun intended) about optical viewfinders forever! I don't like waiting for the electronics to turn on before being able to frame and compose images (and even decide it want to take a shot), so it seems that an OVF is the perfect accessory! The concern I have is carrying around 2 or 3 of them to properly frame my subject based on the lens I have on the camera. I seem to recall that back in the "old days" there were sometimes lines engraved in the VF optics to indicate the field of view for particular focal lengths. Is that true of some of the modern VFs? I suspect not or the advertisers would include TTV ("through-the-viewfinder") images to show the purchasers what they were getting. Comments?