I've been using my light meter for years (Sekonic 558c) and I've been researching as well for a long time and it's been really difficult to find information on how to properly use a light meter. I have tried books, tutorials, skein videos, workshops and even film school but nobody can tell me how they do it.
I know light meter gives you certain information and you decide what to do with that. I know light meters and cameras can very a lot and I know how to compensate or calibrate the meter for a certain camera or gamma. I understand 18% gray, and the zone system, incident and reflected meters. But I know that aiming the meter towards the lens is not going to give me the precision that I'm looking for.
Here is my example:
I'm using a incident meter, I have a person sitting in front of the camera, facing the lens. I have a light source 90 degrees on the right side, easy right? If I aim the meter towards the lens it is going to compensate for the lack of light on the left side, average both sides and it will give me totally not accurate reading. If I point the light meter towards the light source (I guess is the best way to do it) It will give me a reading that is not taking into consideration the shadow on the left side, and it will be "properly exposed".
I have done this for some time and I feel like even when my light meter is properly calibrated for the camera it feels a little underexposed. Is Lambert's Cosine rule affecting that light? Because if the light were aligned with the camera angle then I would have a "on the spot" reading. But in reality (the example) I have the light 90· on the side and I'm measuring towards the light. Is the light reflected from the subject affected by Lambert's Cosine rule? Do I have to compensate? I learned from photography class that when they use "Sunny 16" If the sun (light source) is behind you, you don't compensate. If the sun is on your side then you compensate bu half a stop and if the sun is against you the you open up one stop. I have been using this same compensation values with my readings and it had helped me get even better exposures. Why is this important? Well I want to be able to trust my LM and my judgment when lighting a scene, I want to be able to determine "proper exposure" and get consistent results every time so I can take it from there for more artistic interpretations.
What do you think? Can you share your experience or even better your technique?
Thanks in advance