I don't agree that you need to set the meter for color negative film at half the box speed. It's true that color negative film is more tolerant of underexposure than overexposure but careful metering can help. Light meters are calibrated to 18% gray. If you point your camera/meter at something brighter than a mid tone and do not compensate for the extra brightness by giving additional exposure then you will get an underexposed frame. To practice this, try metering off of an 18% gray card. In a situation where you are not metering off of a mid tone, adding one stop of exposure can help but this will not always be the level of exposure correction you need. If metering is done properly then you can shoot color negative film at box speed and get good results. Each camera has a different kind of metering. There is average metering, center weighted metering, bottom center weighted metering, spot metering and matrix metering. None of these systems will give you a perfect exposure in all situations but each will allow you to get as close to a good exposure as you need to get if you understand how to use it.