Metering mode is how camera evaluates how should the brightness be distributed in a photograph.

Different cameras/ makes have their own set of algorithms and metering modes. 

Canon offers the following which varies basis the model:

• Center-weighted - When subject is largely in the center of frame
• Evaluative - for landscapes to get good overall exposure 
• Spot - When in any scene you want to highlight a particular area, high contrast scene where you want to correctly expose
• Partial Metering

Nikon offers the following - 

• Matrix
• Center-weighted
• Spot
• Highlight weighted

Sony offers the following - 

• Multi-pattern
• Center-weighted
• Spot
• Entire screen weighted

Limitations of Metering mode - 

If you want to learn more about metering mode, below are the links of good resources - 

• https://www.youtube.com/watch?v=vdccYmicb1E
• https://www.youtube.com/watch?v=R_is1Phj5rU

Back to Photography basics