Quote Originally Posted by markbarendt View Post
IMO the most reliable type of meter is an incident meter. Reflective measurement can be done Very well too but it typically requires more experience. As you have found, it requires judgement to pick the right point in the scene.

Adjusting to 1/2 box speed adds more safety factor but there are downsides to using extra as a blanket fix, like slower shutter speed, more grain, ... It is not a magic bullet.

Personally I incident meter and shoot at box speed and develop normally; systemic failures are very, very, rare doing this.
I agree with Mark.

I would just add to remember that in high contrast situations (imagine a building which is half lit by full sun and half in shade) when using an incident light meter and a positive film you would take the measure by placing the light meter in full light (with the dome pointing toward the camera) while with an incident light meter and a negative film you would put the light meter in the shade (again with the dome pointing toward the camera).

Using an incident meter still requires to remember that with slides you expose "for the highlights" and with negatives you expose "for the shadows" when you have a scene in front of you with both zones in bright sun and zones in the shade.

Having said that, an incident light meter and "box speed" yields very good results in most situations, while spot metering is more prone to errors and I think is warranted only with high-contrast situations and slide film when you want to exactly understand the way the highlights will be rendered on slide film.