KODAK VISION 3: ABOUT THE RECOMMENDED ISO

Reversal motion picture film (the one that after its processing provides a positive image), you must always expose it to the marked ISO speed, except for a remembered exception, the late (in Single-8 and 16 mm) Fujichrome Velvia 50 that, for motion picture use, the correct expose was at 25 ASA.

125 or even 100 is the correct value to expose Kodak Vision 200

KODAK NEGATIVE FILM: RECOMMENDED OVER-EXPOSURE.
For Kodak motion picture negative films,  of the Vision 3 series, if the camera is perfectly adjusted, I personally think that must be shoted with overexpose of two thirds of stop, although directors such as Marc Martí or scan technicians such as José Luís Sanz or Matteo Richetti thinks that thee best performance for the Kodak Vision range is obtained by overexposing a complete full stop. 
Matteo told me: "I agree that for scanning negative is better overspose one stop, scanning undesposed or even correct esposed negative for print is a big challenge as negative are low contrast, so even using a 14 bit sensor 3... 4 bit are loss. Old CCD scanner (even basic dia scanner) compensate in hardware, but with area CMOS sensor (like the ones all today scanner use) are not made natively to scan negative".
This rule is only valid if the film is fresh and the camera is perfectly calibrated, in a professional service such as that provided by Microdelta Balears.
In this way, I expose the Kodak Vision 50 to 32 ASA, the Kodak Vision 200 to 125 and the Kodak Vision 500 to 320.

• Other important point: for negative Vision film, is much better to get the exposition value in parts of the picture with shadow.

Last year, in the shoting of Spitsbergen: the Guardian of the Arctic, I made a special experiment: I shot Kodak Vision 500 at only 50 ASA, and Ludwing Drasser, from Andec, do for me a pull processing of two stops,  that is, the final result to 200; the result, amazing and unheard of, can be seen here: 


SPITSBERGEN: MAKING... IN PROGRESS! from IB CINEMA Motion Picture Films on Vimeo.