exposure - How do I use spot metering?

What's the right way to use spot metering? Is it better to use in manual mode than one of the priority modes?

There's a question about when to use spot metering, but none that serves as a tutorial to describe how to use it.

Please address the issue of exposure compensation. I am under the impression that spot metering is hard to use in aperture priority because you can't (to my knowledge) over/under expose an image in these modes since the camera will adjust other variables to get the proper exposure. (So I need to meter off something that is gray-ish since I can't meter off something black and compensate?)

This question is motivated by another one that I asked here. It became clear that I didn't really know how to use spot metering.

Answer

I wrote a tutorial about this very subject on my website. You can read it here.

To summarise, there are two advantages to using it in manual mode:

1. Once you've set your meter for the prevailing lighting conditions, you shouldn't need to worry about the exposure again (unless you need to change the aperture or shutter speed, or the lighting changes significantly)


2. Using manual mode allows you to move beyond the 2 stop range you get on most cameras with exposure compensation.

Learn the zones (see link); then find something in your image that you want to assign to a particular zone. Spot metering is the best way to isolate a small part of your image without any extraneous elements getting in the way of the metering. I now shoot almost exclusively with manual spot metering.

Of course there may be valid reasons why it's not appropriate to use manual mode - you may be shooting in rapidly varying lighting conditions, for example. But learning how to use spot metering in conjunction with manual mode will add another tool to your belt.