Mulling over the idea of getting rid of my 2 Pacemaker Crowns and getting a good Speed. Have been perusing through the fleabay putting together ideas. I almost absolutely decided to go for the latest Pacemakers with the top mounted rangefinder because I like the self-contained range light that you can hit with your thumb. No external power source or reaching up and down turning the switch. I could switch the 135 Schneider off one of my Crown Specials onto my "new" Speed. THEN a thought hit me that is possibly turning me off the top-mounted Graphic rangefinders and sending me running back to a Kalart. It is a FACT that if you calibrate a Kalart on an 135 Optar, that a 135 Schneider will be off agreement with that rangefinder. Both are rated 135 on the front ring, hence use the same cam, but they are not exact. And your rangefinder will not be right for the other without re-calibration. But the top-mounted Graphic is cam-driven There is no way to re-calibrate like you can on a Kalart. I can make a Kalart dead-on perfect. So now, it seems that the top-mounted Graphic rangefinders are not at all necessarily accurate, just because you have a 135mm lens on it and a 135mm cam in it. Seems like a Kalart-model Pacemaker is actually the more accurate model. Thoughts?