If you’re concerned about maximum image quality and/or worried about digital “noise,” then you should consider exposing to the right (ETTR.) This means you set your camera to record in RAW (you can add RAW + JPG if you want quick access to a jpg but still want the RAW file to edit) then look at your histogram. Make sure that you have set an exposure that goes as far to the bright side (on the right) without clipping. This gives your post processing software more data to work with. While the photo might look slightly overexposed in your viewfinder or on your LCD, that’s okay, because in post you will edit it so that it looks fine, but you’ll reduce the chances that you’ll have digital noise.
There is exponentially more data in each quadrant of the histogram as you move left to right. All that data in the far right quadrant is your friend.
Here are a couple of things to remember…
- If you are shooting at your camera’s base ISO, ETTR is much less valuable and not really necessary – as you crank the ISO, ETTR becomes more important
- To be safe, bracket (even though you are shooting RAW) and make one exposure about a half stop lower than the “perfect” exposure – then make two more, half-stop up exposures (to the right) to make sure you go as far as you can without clipping (blowing out the highlights.)
- ETTR is just a tool – it’s not a religion or a mantra. It’s not necessarily a best practice for all photographers in all situations. For those of us who use Micro Four Thirds sensors, it’s just another way to improve overall image quality when working with higher ISOs.
With proper ETTR technique, your images have as much detail in the shadows as they possibly can, without any of the highlights losing information along the way. It also helps to reduce noise and gives photographers who are looking for the best image quality they can coax out of their camera sensor.