I use a Manfrotto mount to attach my fullframe 6D on the NN3.
I found my NPP for this setup:
Lower rail is at 6,9 cm (because of the manfrotto mount)
Upper rail is set at 9,65 - and I can't get any further backwards.

Actually I think I could use a few millimeters more on the upper rail (the tho poles I set up still moved a bit when turning the NN3).

Can it be done?

I cannot find the rail settings on NN's homepage. If some of you NN-guys is listening. Would you please add it?

Would some of you guys post your rail settings with a Canon 6D and a Canon 8-15mm lens here?

Best regards