Why you should “Expose To The Right” – Part 2

Continued from Why you should “Expose To The Right” – Part 1

Is ETTR still relevant with the latest improvements in sensor technology?

Yes, because not everyone has the newest fancy camera. And, even if you do own the latest technology, it still may be a good idea to employ the principles of ETTR. Even today’s best sensors will only tolerate so much lifting of the shadows before noise becomes a problem. The caveat is that you must have enough knowledge of your specific camera, and the experience to control your exposure without blowing out the highlights.

The two images above are enlargements showing just the shadow details of two different exposures, which were then normalized in post processing. The left image was exposed according to the camera’s meter and was darker. The right image was ETTR. There is noticeably more noise and loss of tonal detail in the image on the left, which was exposed according to the meter reading. Canon 5DsR, 24-105mm f/4L lens.

When not to expose to the right.

  • Low contrast scenes will not really benefit from ETTR if there are no dark shadow areas. A low contrast scene exposed to the right has the potential for visible sensor saturation artifacts (banding). Instead, a nice, mid-range histogram is what you want for these types of scenes.
  • Avoid blowing out areas with smooth luminosity gradients, because this can also lead to banding.
  • If you are, say, an event photographer, it’s easy to clip highlights if you’re not careful because lighting and subject change so quickly, so be sure to keep a close eye on the histogram, and err on the side of underexposure.

This image of Whooper Swans flying in a snow storm created a challenge to get the exposure right.

Watch for clipping in RGB channels.

Don’t forget to monitor the RGB channels for clipping as you adjust your exposure. Some cameras allow you to see all three channels — red, green, and blue — in a histogram. It is important to also look for clipping in these channels, which might not show up in the monochrome version of the histogram. The red channel is the most common color to clip. Blue is the next most common, but clipping can occur in any channel depending on your subject. If you see clipping in any one of the individual channels, then reduce the exposure until the clipping is eliminated. 

I had to carefully monitor the red channel when I made this image to ensure that detail in the clouds was preserved. Fortunately, I had envisioned a dark, moody feel to this piece, so I wasn’t particularly concerned about lifting detail in the shadows. ISO 500, f/16, 1/6 sec.  Sony A7rII with Canon 16-35mm f/2.8 lens.

Experiment.

Each camera sensor will handle noise in the shadows differently. If you want to understand how your specific camera handles dynamic range, conduct your own tests. Using your camera’s native ISO, bracket several exposures, then normalize the exposure of the bracketed images in a post-processing. Compare the details in the shadow areas, and look carefully at the tonal range across the entire image. How does the noise compare in the different exposures? What do you consider an acceptable amount of noise?

As you experiment, keep in mind that most cameras only offer an approximation of the actual histogram, and small highlights may fail to display properly on the camera’s LCD screen. In this case, monitoring the “blinkies” — over-exposure alert — is a good idea. Some blown-out highlights can be recovered later in post-processing, but not all. Much depends on the image and the camera. In post-processing, you will be able to examine the full dynamic range of the histogram using raw processing software such as Adobe Camera Raw, Adobe Lightroom, CaptureOne, or Adobe Photoshop.

This high-contrast image was difficult to make with just a single exposure, but since I didn’t care so much about detail in the forest areas, I prioritized the exposure for the clouds. The RAW photo was quite dark, but I was able to preserve all the beautiful detail in the sky and mountains.

Is ETTR the right approach for you?

As for your own practice, you will need to decide if it is worth it to go through the trouble to capture every bit of detail possible from your exposures. For example, if you typically post your images to Instagram, then the benefit of ETTR is likely to go unnoticed and unappreciated. But if you are like me and print your work, then you’ll be glad that you took the extra care to get the exposure right in the field so that all that rich detail is there in your print.

About Author Charlotte Gibb

Charlotte Gibb is a contemporary fine art photographer based in the San Francisco Bay Area specializing in landscapes of the Western United States. Her images are often taken in familiar places for the well-versed landscape photographer, but she prides herself on her keen an eye toward the subtle and sometimes overlooked beauty of the natural world. Charlotte earned her Bachelor of Arts Degree from the Academy of Art University in San Francisco and has exhibited her work in several solo shows throughout California. Her darkroom, long gone now, has been replaced with digital darkroom tools, and her style has evolved from a somewhat journalistic approach, to one that pays tribute to the natural world.

  • Mark, you are quite right. The exposure made at 1/13 sec. was initially decidedly darker than the one at 1/20th. But, I “normalized” (adjusted the exposure, white and black points) the RAW exposure made at 1/20th in post processing (Adobe Lightroom) to match the image made at 1/13th so that I could compare the detail in each. Does that make sense?

  • Al Juliano

    Thanks, Charlotte. A very useful article.