Eloquent Nature by Gary Hart

Cameras aren’t so bright

Your camera is stupid. Sorry (so is mine). And while I’ll gladly cite many examples, right now it’s just important that you understand that your camera thinks the entire world is a middle tone. Regardless of what its meter sees, your camera will do everything in its power to make it a middle tone. Sunlit snow? Asphalt at midnight? It doesn’t matter–if you let your camera decide, it will turn out gray.

Modern technology from camera manufacturers offers faux-intelligence to help overcome this limitation. Their solution, called “matrix” or “evaluative” metering, compares a scene to a large but finite internal database of choices, returning a metering decision based on the closest match. This works pretty well in conventional “tourist” light, but often struggles mightily in the warm or dramatic light artistic photographers prefer. If you want to capture more than documentary “I was here” pictures, you’re much better off taking full control of your camera’s metering and exposure. Fortunately, this isn’t nearly as difficult as most people fear.

Metering modes

Your camera’s metering mode determines the amount of the frame the meter “sees.” Since most images have a range of tones from dark shadows to bright highlights, the meter will take an average of the tones it finds in its metering zone. The larger the area your meter sees, the greater the potential for a wide range of tones. I prefer “spot” metering because it’s the most precise, covering the smallest area of the frame possible, an imaginary circle in the center three or so percent (depending on the camera) of what’s visible in the viewfinder. Spot metering isn’t available in all cameras–in some the most precise (smallest metering zone) metering mode available is “partial,” which covers a little more of the scene, somewhere around ten percent. Check your manual for the metering modes it offers.

Exposure modes

Don’t confuse the metering mode with the exposure mode. While the metering mode determines what the meter sees, the exposure mode determines the way the camera handles that information. Most SLR (single lens reflex) cameras offer manual, aperture priority, shutter priority, and a variety of program or automatic exposure modes. Serious landscape photographers should disdain the full automatic/program modes in favor of manual (my recommendation) or aperture priority (shutter priority is not for landscape photographers) mode.

If you select aperture priority mode, you specify the aperture (f-stop) and the camera dials in the shutter speed that delivers a middle tone based on what the meter sees. But you’re not done–unless you really do want the middle tone result the camera desires (possible but unlikely), you then need to adjust the exposure, using exposure compensation (usually a button with a +/- symbol), to set whatever value you think will give you the exposure value you want.

I prefer manual mode because it gives me more control, and I think it’s easier. In manual mode, after setting my aperture (based on the depth of field I want), I point my meter (in my 1DS Mk III that’s the center 3% of my viewfinder) at the area of the scene I want to meter and dial in whatever shutter speed gives me the amount of light I want. That’s it. (In manual mode you can ignore the exposure compensation button.)

Expose yourself

So let’s review. Start by selecting your metering mode (the way it “sees” the scene), then take your camera out of auto exposure mode and put it in manual (my recommendation) or aperture priority (if you prefer) mode. (Remember, I’m a landscape photographer so I never use shutter priority; if you’re shooting action, you may want to consider shutter priority if you don’t like manual.) Before metering, set your camera to whatever aperture you think the composition calls for. Then meter, remembering that your camera isn’t telling you what the exposure should be, it’s telling you the exposure that will make what it sees a middle tone. Finally, correct the meter’s middle-tone suggestion by dialing in the shutter speed (in manual mode) or exposure compensation (in aperture priority) that gives the correct exposure.

What’s the correct exposure? That’s a creative decision that’s entirely up to you–feel free to play until you’re comfortable with your results. The more you do it, the easier it gets.

For example

Below are some sample images and the thought process I followed to get the exposure.

After choosing the aperture that gave me the depth of field I wanted, I spot-metered on the sunlit portion of El Capitan and dialed my shutter speed until the meter indicated +1 (one stop above middle tone). I could have gone a little brighter without clipping (blowing out) the highlights, but I wanted to retain the color in the sky, and since I was more interested in the tree's shape than its detail, I really didn't care if the branches were black.

Here's one matrix/evaluative metering would have made a mess of. The dynamic range (range of light between the darkest shadows and brightest highlights) was off the charts. Rather than compromise, I exposed to hold the color in the sky and let the foreground go to silhouette. I metered on the brightest (goldish) part of the sky next to Half Dome and dialed my exposure to +.3 (1/3 stop above middle tone). The sky was brighter than what you see here, but underexposing like this allowed me to emphasize the sky's rich blue and the very Yosemite outline of Half Dome and Sentinel Dome. The highlights in the thin lunar crescent were clipped, but I didn't care about the moon's detail, only it's shape.

Who says you should never blow your highlights? Here I metered on the brightest part of the poppy (near the top), setting my exposure to .7 (2/3 stop above middle tone). Everything you see that's white is blown blue sky (except the "star," which is a sliver of the sun).

Now get to work

Don’t try to apply all this for the first time when you really, really want the shot. Instead, find a time when the results don’t matter and play with your camera to find out how much control you have over exposure. In fact, you can do this right now in your backyard or even sitting right there in your recliner. Meter something nearby, set an exposure, and click. Look at the result, adjust the exposure, and click again. Watch your histogram, and watch how its shape shifts right as you increase the exposure, or left as you decrease it. Continue doing this until you’re confident in your ability to make a scene brighter or darker, and can consistently achieve the exposure you expect.