Mirrorless Metering

Gary Hart Photography: Dawn Reflection, Trillium Lake and Mt. Hood, Oregon

Morning Peace, Trillium Lake and Mt. Hood, Oregon
Sony a7R
Sony/Zeiss 16-35 f/4
.5 seconds
ISO 100

Because I don’t want my camera making any decisions for me, I’ve always metered in manual mode. For most of my photography life, my manual metering approach was to start with the best f-stop for my composition, spot-meter on the brightest part of the scene, and dial my shutter speed until the meter indicated the proper tone.

In my film days I sometimes hedged my bets by bracketing high dynamic range scenes; with a digital camera, rather than bracket, I check my histogram and re-shoot only if I missed the exposure on the first try. While this approach has served me well, my metering life became much easier with the advent of live-view (pre-capture) histograms, and easier still since my switch to mirrorless (Sony Alpha).

Trust your histogram

The histogram is a graph of the tones in an image (you can read more about it here). Instead of clicking and hoping as we did in the film days, the addition of a histogram on virtually every digital camera gives photographers instant feedback on the exposure of each image. Better still, live-view histograms give us that exposure feedback before we click the shutter.

While each camera manufacturer offers a variety of metering mode options and terminology to label them (spot, partial, center-weighted, evaluative, matrix, etc.), your metering mode doesn’t matter if you’re metering with your histogram. Using the pre-capture histogram, I start the metering process as I always have, using my camera’s best ISO (100 for my Sony a7RIV), and the best f-stop for my composition (unless motion, such as wind or star movement, forces me to compromise my ISO and/or f-stop). With ISO and f-stop set, I slowly adjust my shutter speed with my eye on the histogram in my viewfinder* (or LCD) until I’m satisfied with the histogram. Ideally I’ll have a little room on both sides of the histogram, but in a high dynamic range scene my histogram might not fit the boundaries, in which I usually add exposure until the histogram graph bumps against the right side.

Most mirrorless bodies offer highlight warnings in their pre-capture view (called “zebras” on my Sony bodies—your terminology may vary). While these alerts aren’t nearly as reliable as the histogram and should never be relied on for exposure decisions, I use them as a signal that it’s time to monitor my histogram more closely. The first time I meter a scene, my current exposure settings can be far off from where I’ll end up—in this case, I push my shutter speed fast until the zebras appear, then refine the exposure using the histogram.

Because I trust the post-capture histogram a little more than the pre-capture histogram, when there’s little margin for error in my exposure (high dynamic range), I verify it by checking the review (post-capture) histogram. While the luminosity (white) histogram reveals the detail you captured, it doesn’t tell you if you lost color. Washed out color is always a risk when you push the histogram all the way to the right, so it’s best to check the RGB (red, green, blue) histogram to ensure that none of the image’s color channels are clipped.

An often overlooked aspect of mastering in-camera metering is learning your camera. Not only does every camera interpret and report its exposure information a little differently, the histogram returned is based on a jpeg—raw shooters always have more information than their camera reports and it’s important to know how much more. For example, with my Sony a7R series bodies, I know I’m usually safe pushing my histogram’s exposure graph a full stop beyond the boundary, and I have no problem using every available photon when necessary.

For example

Gary Hart Photography: Dawn Reflection, Trillium Lake and Mt. Hood, Oregon

Dawn Reflection, Trillium Lake and Mt. Hood, Oregon

A few years ago I was photographing a sunrise at Trillium Lake, beneath Mt. Hood and just south of the Columbia River Gorge. Finding the open sky on Mt. Hood’s east side much brighter than the lake and (especially) trees, after composing and focusing, I cranked my shutter speed until the zebras appeared (they usually show up before the histogram reaches the right side), then clicked more deliberately until the histogram hit the right side.

At that point the left side of the histogram was still clipped slightly, but because I knew I still had one more stop to play with on the highlights side, I clicked one more time with my eye on the left (shadows) side of the histogram and saw that the shadows were still slightly clipped. Since each click adds (or subtracts) 1/3 stop, I had two more clicks before I reached my 1-stop-over highlight threshold. The second shutter-speed click moved the left side of the histogram just enough to eliminate the clipped shadows, and I was ready to shoot (with 1/3 stop to spare!).

After capture, I checked my RGB histogram to ensure that I’d captured all the scene’s detail and color. In Lightroom I was able to easily recover the highlights that my camera told me were clipped, and pull all the detail I needed from the shadows.

     * Though these instructions are for mirrorless shooters, much of what I say also applies to DSLR shooters with access to a live-view histogram.

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High Dynamic Range Mirrorless Metering Gallery

Click an image for a closer look and slide show. Refresh the window to reorder the display.

8 Comments on “Mirrorless Metering

  1. Great article Gary, as is your current OP article. Being new to Sony(a7ll), do you use use the exposure comp dial to adjust your speed?

    • Thanks, Ralph. I shoot in manual mode only, and control the exposure with the shutter speed. The f-stop is determined by the scene, and I only deviate from ISO 100 when motion is a factor (so I can get the right exposure and motion effect at the f-stop the scene calls for).

      • Very much appreciated Gary. Always used my Nikons on full manual and over-thought the process now I’m a Sony user— you are very persuasive 😉. All is good and thanks again for taking the time to assist…

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