The viewfinder is the Mk2 from Helios with 35mm, 85mm & 135mm markings. It's pretty much useless on the Fuji as its off centre and has a cropped censor so depending on the lens it's never going to be exact. I bought this for my rangefinders for better framing. I just wish Fuji would bring a hotshoe OVF with digital overlay out for the X-E1. Surly it can't be hard to do.