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.
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.
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.
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.
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.