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 ?
Try doing an incident reading with the meter pointed the opposite direction that you are shooting. This usually gives me a good reading for outdoor shots like landscapes.
Metering for transparency materials is opposite that of negative materials. For transparency meter the highlights and let the shadows fall where they will. In negative materials expose for the shadows and alter development for the contrast.
Transparency materials have a much tighter density range then negative materials. 1/3 stop can make a great difference.
Using transparency materials you might also want to start "bracketing" your exposures. If you aren't familiar with the term it means to set the camera for what the meter says and then also make exposures 1/2 stop in either direction as well. Sometimes when you find a great subject you could even bracket further than this to say a stop or more.
The incident and reflected readings on my Digisix agree remarkably closely. I can't imagine why yours wouldn't. Could it be that your reflected reading being skewed by bright objects or too much sky?
Most points already covered. You are most probably using a Velvia type film which is very limited as far a latitude in exposure is concerned. When taking a reflective reading
be sure you are getting a reading from the highlight only, it is so easy to get some sky
or other zone in that will give you a false reading. Incidentally, I have found that the correct exposure for MY exposures is when velvia is rated at 40asa not 50. Stan. L-B