I used last week a handheld meter in 'reflective' mode for the first time (Gossen Digisix). The first film developed (slide E-6)showed terrible underexposure (probably 1.5 to 2 stop under).
What should I do: use the meter only in incident mode (I shoot mostly landscapes) or calibrate the meter with the help of the matrix metering of my SLR (nikon F100 never failed in landscapes) ? Other techniques ?