Advantages of Manual Spot Metering

These lovely cowgirls were photographed on my Winter Wildlife Workshop in Montana two seasons ago. Shot with a Canon EOS 7D Mark II, 1600 ISO, EF 100-400 IS II at 214mm, F10, 1/1300th sec. hand held as the ladies ran right at the camera. ©Adam Jones

Make no mistake, I love the current digital age of photography, and the exciting advances it brings with it.   During numerous digital photography workshops and lectures, I’ve noticed fairly advanced photo enthusiasts don’t really understand exposure and how their camera’s metering system works.  Those who have traveled with me know I’m a big fan of Evaluative Metering (Canon) Matrix Metering (Nikon) for nearly all of my landscape, and macro photography.  I’ll confess that I’ve not used TV Mode  (shutter priority) in over 25 years.  My go to metering methods are Evaluative for most static subjects, and Manual metering for wildlife/action situations.  I simply have not found a situation where TV is necessary.  Manual metering and Evaluative work very well for everything I shoot.

This extremely rare Amur Leopard was photographed at Triple D ranch in Montana during my Winter Wildlife Workshop. Shot with a Canon EOS 7D Mark II, 1600 ISO, EF100-400 IS II at 100mm, F9, 1/1000th sec. hand held.

I use Evaluative metering for a good percentage of my everyday shooting and love it, but there are limitations.  In Evaluative metering, you choose the Fstop and the camera automatically selects the shutter speed. Exposure compensation adjustments are made with the command dial on the back of Canon cameras to make the image lighter or darker than suggested by the camera.  This is a very reliable and efficient mode in many cases, but when your subjects are moving around, significant exposure errors can occur.  Incorrect exposures in AV mode occur when your subject moves in front of backgrounds of varying lightness or darkness.  The camera will vary the exposure depending on the background, and this can lead to exposures way off the mark.  

For example, using evaluative metering, a bird on the ground may be exposed perfectly in its surroundings, however, when that same bird suddenly flies into the sky, it may be rendered nearly a silhouette because the bright sky fools the metering system into underexposure.  We must be a bit smarter in these situations.  Even zooming your lens can change the exposure, even when the light is not changing.

Lets say you have a dark bison standing in a grassy meadow in Yellowstone and you have a zoom lens on your camera.  At the wider setting the dark toned bison is a relatively small percentage of the scene and evaluative metering may be right on, however if you zoom way in on just the bison, now the camera is seeing a completely different scene, and metering very differently.  Now the bison is big in the frame, the meter reads a lot of dark tones from the bison, and gets fooled into overexposing the bison.  The light did not change as we zoomed, but the in camera meter changed as the zoom added or subtracted background.

To avoid these potential pitfalls, use manual metering in conjunction with the in camera spot meter.  In manual metering you must set the aperture and the desired shutter speed for correct exposure.  The great benefit is that once exposure is set correctly, it can’t move until we tell the camera to do so.  It’s so simple, but the benefits are huge.

This beautiful female coyote was photographed during my Winter Wildlife Workshop. She loved running around and jumping in the snow, her joy was obvious! Shot with a Canon EOS 7D Mark II, 800 ISO, EF100-400 IS II at 400mm, 1/2500th sec. F8, hand held for maximum flexibility.

We encountered a perfect scenario on our Canon Destination Workshop in Yellowstone in Sept.  The first morning out we were photographing a herd of bison on a cloudy day in snow.   I suggested spot metering the snow in manual mode, compensate plus two full stops, then simply recompose and shoot away.  Guess what, the exposures were perfect.  Next a flock of Canada Geese burst into flight further behind the bison and alert students captured the birds in flight, again with perfect exposure.  Had they been in Aperture Priority, the geese would have surely turned out as silhouettes.  The bright overcst sky would have caused the meter to underexpose the geese.  It was a very convincing real world learning moment for our students.

So why spot metering with manual mode?  Spot metering is valuable because the area where the meter is reading is clearly defined in the viewfinder.  The beauty is that I now know exactly what I’m metering and simply compensate manually to get the correct tonality on any subject.  In the previous example of the bison in snow, the easiest way to meter for the distant bison was to meter the snow and only the snow, with the spot meter in manual mode, then adjust the exposure to plus two stops.  My preference is to keep the aperture set, and move the shutter speed manually to whatever exposure compensation is required, very similar to the way I work in aperture priority.  If you are accustomed to the controls working a particular way in AV mode, I would also switch the control dials on Canon cameras so the Command Dial and control wheel under your index finger control the same functions in manual mode as they do in AV mode.  Set this way, you will instinctively reach for the correct wheels and dials when the action heats up.

The restricted area of the spot meter is very effective at letting us know what area is being metered.  The problem is that we can’t always, meter right on our intended subject.  In these situations we need to meter something else and transfer that exposure to our actual subject.  A perfect example is a wolf we were photographing at Triple D.  The wolf is not an even tone, it is black, white, and gray, so using the spot meter on the wolf may prove problematic.  The solution?  The wolf was standing on snow, we simply spot metered the snow, compensated the shutter speed to yield a plus two compensation, and our exposures on the wolf were perfect.  The snow is in the same cloudy light as our subject, so making the snow correct at plus two stops compensation, made everything in the frame correct, including the wolf.

This is the alpha male wolf at Triple D ranch and is beautiful to photograph. It was a very heavy overcast day in the forest, so shutter speeds were a bit slower than I would like, but still acceptable for consistent results. Shot with a Canon EOS 7D Mark II, 1600 ISO, EF 100-400 IS II at 160mm, F7.1, 1/640th sec. hand held.

I know this may sound a bit complicated, but it really is not.  In summary, below are my basic manual exposure guidelines that work if used correctly.

Evaluative Metering:  My go to metering pattern when photographing stationary subjects. Take a shot and simply adjust exposure compensation as needed.  I use Aperture Priority mode in most cases for landscapes, therefore the Shutter Speeds are adjusted to make the image lighter or darker.

Spot Metering in Manual Mode:  Useful for moving subjects such as wildlife.  Exposure and F Stop are both locked and set by you.  As subject moves in front of different backgrounds exposure stays set.  The exposure pointer may move off your setting, but the shutter speed and aperture are locked, so don’t panic if the exposure meter says something different after recomposing!

Spot Metering Right on your Subject  - Cloudy or Sunny

(This is the most reliable method when possible)

Average Subject tonality:      No compensation required

Skin Tones:                             +1 Stop
White:                                     +2 Stops
Very Dark:                              -1.5-2 Stops 

Spot Metering off something other than your subject.
Metering average tone in shade: 
filming white subject in shade: (0) Compensation
Metering average tone in shade: 
filming dark subject in shade: (0) Compensation
Metering average tone in shade: 
filming average subject in shade: (0) Compensation

When overcast (soft light) make any tone correct and all tones are correct.
Metering average tone in sun: 
filming white subject in sun: (-1) Compensation
Metering average tone in sun: 
filming very dark subject in sun: (+1) Compensation

Take the two egrets fighting in flight.  There are two ways using the chart above to get to the same correct exposure.  As mentioned above the most accurate way is to meter right off your subject.  This means filling the spot meter circle with nothing but one tone on the main subject.  In this case I spot metered right on the great white egret, and compensated plus two stops for white.  Again this works weather cloudy or sunny.  The other way to get to exactly the same exposure is to meter off something average, and then subtract one stop (minus 1 stop compensation) because the white bird is in the sun.  This method works, but it is up to you to accurately determine something average to meter on, and the average tone you meter from, must be in the same light as your subject. 

This is an image I visualized before it actually happened. The image was captured at the Venice rookery, Florida. Nesting space is tight and knew bickering between rival males is quite frequent. Shot with a Canon EOS 1Ds Mark II, 200 F1.8 lens with 2x teleconverter attached. Captured at effective 400mm, F5.6, 250 ISO, 1/4000th sec.

Hope you enjoy the newfound freedom that manual spot metering provides for subjects moving in front of differing backgrounds.

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