I do not agree with Tom.

Reflective
You can use reflective reading for color print, color slides and black & white film. I have done that for only five decades. Dome off. Aim the light meter at the subject from where you will be taking the photograph. Do not aim it to include the sky [or much of it] because that will cause the light meter to believe that the scene is brighter than it is.

Incident
With the dome on, stand at the subject's position and aim the light meter towards the camera. This can be used for color print, color slides and black & white photography.

I prefer the reflective measurement, but I will use the incident meter for photographic studios, or when the scene is mostly white [snow] or mostly dark since reflective reading are not accurate when the scene is very bright or very dark.

Do not use the dome for a reflective reading, even though there are some at APUG that believe that is the thing to do. I have thoroughly researched that subject on the internet, at Kodak and at many photographic libraries. There are no articles or books that discuss that method. Period. When I talked to optical engineers, their response is that they would like to know what drugs the people who make such recommendations are on. Again, there is no accepted photographic journals nor any photographic books that discuss such blither. Take the blither of using the dome for reflective reading and flush it down the toilet.