Camera Exposure Metering Methods

The Tale behind the Images:

These are landscape photos taken with a recently purchased Canon EOS-350D.   The first photo using an EF-S 17-85mm F4-5.6 IS USM lens was intended to capture the Trumpeter Swan pair that are wintering on the south end of Terrell Lake near Ferndale, WA.   But they were a bit far away for the lens.   The second photo using an EF 70-300mm F4-5.6 IS USM lens is of a seagull, taken in bright, direct sunlight, with the intent to capture feather detail as well as the water transparency, reflections, and ripple.


Method 1:   'Center Spot Meter' mode with +2EV Exposure Compensation.

Recognizing for the first image that the camera's exposure metering in 'Evaluative' mode would most likely clip the cloud highlights and swans because the image's pixel areas for the brightest highlights would be small compared to other tone range histogram distributions, the exposure metering was switched to 'Partial' mode which for the 350D is its closest equivalent to a 'center spot meter' mode and the Exposure Compensation set to +2 EV.   An exposure lock was performed with the view finder centered on the brightest part of the clouds and then the composition was reformed and shutter released.   With this method, "...the camera will attempt to expose the 'cloud' bright point to 18% gray, but the EC=+2 will move this up two stops to 72%, which is close to the right edge of the histogram. So, you get an "exposed to the right" exposure with a half-stop margin above your selected highlight (in case you've made an error in identifying the brightest highlight or to prevent clipping of an individual color channel)...".   A DL-C message board thread further illustrating this, may be found here.

Place your mouse over the image to see the camera download image.
Mouse On and Off Image
. . .Terrell Lake, Ferndale, WA   USA. . .       . . .Jan 18, 2006. . .       . . .(c) IMAGEs by DEN  2006. . .

Image post-processing consisted of recovering shadows and lower mid-tones detail; followed by overall adjustments for brightness, contrast, and saturation using the Color Curves transform; and then sharpening.


Method 2:   'Evaluative Meter' mode, check 'histogram camera playback' image, and adjust Exposure Compensation EV as needed.

Nothing particularly creative or innovative about this method.   While I prefer Method 1, when the scene is a changing dynamic, then shoot using the default camera metering mode, check the histogram image display for clipping keeping in mind the histogram is based upon 'luminance' and to allow an extra 1/3 or 1/2 EV margin for color channel clipping, and keep adjusting EC as needed.   For post-processing, choose the best compromise exposure/composition image.   For the Glaucous-winged Gull image, the camera metering method was 'evaluative' and this was the 3rd shot with a -1.67 EV exposure compensation.

Place your mouse over the image to see the camera download image.
Mouse On and Off Image
. . .Drayton Harbor, Blaine, WA   USA. . .       . . .Mar 4, 2006. . .       . . .(c) IMAGEs by DEN  2006. . .

Again, image post-processing consisted of recovering shadows and lower mid-tones detail; followed by expansion to 'full dynamic range' in the Levels and Color transform with overall adjustments for brightness, contrast, and saturation using the Color Curves transform; and then sharpening.


Main Page

Illustrated Tutorials

You are welcome to see other IMAGEs by DEN.
Last Update: 060328 rev 1: added 'seagull'