Exposing Ektachrome 100D, Kodak 50D and Fuji Velvia 100 need not be a problem anyway with the (big) Nizo cameras e.g. the (S) series 480, 561, 800, 801, Professional (the 'small' Nizos I don't know):
With Ektachrome 100D and Fuji Velvia 100 (both daylight material): set switch lightfilter on your Nizo to 'daylight', not 'artificial light'.
If you don't set it to 'daylight', the camera will expose at ASA 160 instead of ASA 100. The Nizos are different in this from other cameras.
Kodak 50 D should be well exposed as it is, because it's close to the former ASA 40 from the Kodachrome cartridge.
Recently I also exposed the new Wittner 200D Aviphot Chrome in my Nizo 561.
This cartridge is notched at ASA 250. Nizo set to 'artificial light'. Really good exposure, also because the 200D is an extremely flexible film concerning exposure. The Nizos can read up to ASA 160.