For parts 1 & 2 go to the Articles page at the top.

In this part, we will talk about the various metering modes available and how each works. Much like the previous “tutorials”, this will be a very basic introduction to the metering modes and when/how to use them. Let me start off by naming the metering modes that are available in most consumer and prosumer cameras. The one that most people are used to is Evaluative mode. In this mode, the camera has a set number of “zones” that it will look at and attempt to find the best reading. In general it is assumed that the more zones the better the metering. The other modes available are center weighed, partial, and spot metering. I won’t go into details about how each mode works, you have a manual for that.

One thing I tell people who are just starting out in photography is that the meter lies to you. You’ll find out why by the end of the article.

The following pictures are of the same scene under the same lighting conditions and shot in Av (aperture priority).

Taken with Evaluative metering mode.

Taken with Evaluative metering mode.

Taken with Partial metering mode.

Taken with Partial metering mode.

Taken with Spot metering mode.

Taken with Spot metering mode.

Taken with Centerweighted Average metering mode.

Taken with Centerweighted Average metering mode.

As you can see from the pictures, there is quite a bit of difference in the exposure from mode to mode. The differences are in how each mode “sees” the scene. So when should you use each mode? To keep it simple, let me just put it this way. Evaluative mode is usually the best for most situations. Partial is good for when the subject is in the middle of the frame and is being back lit. Spot is good for tricky situations where you want to expose for one portion of the scene (for example, the skin of your subject). Centerweighted Average is good for when the subject is again in the middle of the frame but isn’t necessarily back lit. Now my descriptions are very vague and you probably won’t get much out of it. The reason for this is simply due to the fact that once you are comfortable with one of these modes there really isn’t a need to use the others except for very special situations or if you’re shooting in one of the semi-auto modes such as P, Av, and Tv without using EC (Exposure Compensation). As you gain more experience, you will start to think like the camera and the metering mode you are comfortable with.

I use Evaluative mode almost exclusively except for the exceptions I stated above. I know from experience that in the pictures posted above, that I would need to overexpose slightly. One thing that needs to be said when talking about metering modes is that the meters will always try to go for 18% gray. What that means is when shooting a white piece of paper that fills the frame, the camera will give a meter reading that will make the paper appear to be 18% gray instead of pure white. Again to keep things simple, I won’t go into much detail about this. You can look it up on Wikipedia or elsewhere if you’re truly interested. So in the images above, I know to overexpose slightly because the meter will see the white turtle and give a reading that will underexpose slightly making it appear to be 18% gray (especially true if using partial or spot metering). In the beginning of the article, I said that the meter lies to you. It’s not really true in the literal sense. The meter sees in 18% gray, it likes the world that way and it feels safe there. It lies to you because it see things differently :p

That’s it for this article, I have more planned which will build on this and the previous articles. Not sure what I’ll write on… any ideas, suggestions, comments? Let me know in the comments section! Till next time…