Multi-spot metering


In photography, the metering mode refers to the way that a camera determines the exposure. There are typically, 3 kinds of metering:

  • spot
  • center-weighted average
  • multi-zone or multi-spot

Spot metering typically works by using the focus point for the source of the metering. Center-weighted average places a higher emphasis on the center spot, but includes the rest of the frame as part of the average. Multi-zone or multi-spot is similar to spot metering, but it allows you to select more than one spot (you’ll probably see diminishing returns somewhere between 3 and 5 spots). Multi-spot can be helpful if the frame includes some extremes of light and dark.

Center Spot Metering

I wanted to take another stab at shooting the Symantec Cafe at sunrise with multi-spot (multi-zone?) metering to see if I could keep from blowing out the sky. All of these shots were taken on a tripod (no changes to the tripod between shots and the only changes to the camera were choosing the spot metering locations). First, I did a shot with spot metering using the default center spot. As you might expect from looking at the picture, the sky was too light and the histogram shows that the highlights were blown out.

Multi-Spot Metering

This is the same shot, but this time, I’ve taken several spot meters (the Canon 1Ds Mark II will record up to 8 of them for a single shot). One of the sky above the cafe, one of the reflection, and one of the dark areas near the umbrellas. You may be able to tell that there is a difference in the brightness between the sky above the cafe and the the sky at the left side of the picture. The histogram shows this left part is still blown out.

This is the same shot, I did (roughly) the same spot meters (I have to take the camera off the tripod, take the metering and put it back on the tripod, so they’re not exactly the same), but this time I added one on the left side, right above the cafe, where things are the brightest. You should be able to see that none of the sky looks pure white, and the histogram agrees that none of the highlights are clipped.

The above shots went through Adobe Lightroom 3 for tagging and cataloging purposes, but were otherwise unaltered.

Corrections for 2nd shot

This is the second shot, processed in Adobe Lightroom 3 with Auto White Balance, and Auto Tone. The colors are slightly warmer, and given that it’s sunrise, I think it looks better. You can still see that the left side of the sky and the bottom left part of the reflection are too bright, and the rest of the picture is still a little too dark.

Corrections for 3rd shot

This is the third shot, also processed in Adobe Lightroom 3 with Auto White Balance, and Auto Tone. Here we can see that none of the sky is blown out, which is good, although according to the histogram some of the shadows got clipped. Seems that its always a balancing act.

Of course, since the blinds were drawn in all the windows, you can’t see the lights shining out and the Cafe doesn’t look nearly as interesting.