spot metering function

[darktiger]

Tell me about this feature and if it is worth it. What applications does this feature allow? For those who have it do you tend to leave it on?

[iCe]

I use it if the subject is backlit and I care more about the subject being exposed correctly than I do the back lit area being exposed correctly.

[JohnT]

In addition to Michael's example, spot metering is also useful when the subject is brighter than the background. Evaluative will overexpose the subject if you don't dial in negative EC. Center-weighted won't help much as neither will partial. With spot, you can meter the subject so that it's exposed correctly, ignoring the background if it's less important.

Edit: Let me add that I shot without spot for a year and a half before getting my 30D, and I made a lot of adjustments in ACR because I seldom was able to get the exposure perfect in those situations. With spot, I'm hoping that changes.

[Duffy Pratt]

Spot metering can be useful whenever there is something you are shooting that you are confidant is a neutral tone (or if you know how far off neutral gray it is). When I'm talking about neutrality here, I mean in terms of luminosity. The color is irrelevant. It becomes critically important when there is a very large contrast ratio in the subject, and you need a certain part of the subject to be neutral or close to it.

Examples, in addition to what have been mentioned, are shooting in a snow field, shooting at night, shooting on the water on a sunny day.

Duffy