it it is the lens that has the No Parallax Point, not the camera body, so you just need the settings for your Samyang 8mm lens.
See http://hugha.co.uk/NodalPoint/Index.htm and click on the icon to look at the Samyang 8mm lens.
Also take a look at http://michel.thoby.free.fr/SAMYANG/...%20report.html.
The NPP will depend on how many shots round you take.
With the Samyang 8mm it appears that the recommendation is 6 at 60 degree intervals so the NPP will be closer to the front than if you chose 8 shots round at 45 degree intervals.
I prefer to shoot 8 round to get more overlap for more Control Point coverage and more scope using the Mask tool.
Also see http://www.johnhpanos.com/epcalib.htm.