Why dynamic range is important and how to use it
„Dynamic range describes the ratio between the darkest and the brightest values your camera is able to capture.“ (Wikipedia)
What does this mean?
Let’s say you have taken a picture of a sunset. The sky is correctly exposed. You can see its beautiful colors. The foreground of your image however, is crushed to black and contains no information (visible details). This is where dynamic range comes into play. The more dynamic range your camera has, the more you are able to brighten the shadows and recover the lost detail (assuming you are shooting in raw format).
A camera with low dynamic range would provide no useful information when pushing the shadows. Shadows would be noisy and you’d be better of leaving the foreground of our sunset black. It’s totally fine if you like it that way. However, if you prefer (like me) to have your sky and foreground visible, you need a well exposed shot containing sufficient dynamic range and some editing skills to make the details in both bright and dark areas visible while still mainting an overall natural appearance of your image.
Why would you need to push(brighten) the shadows (dark areas)?
It depens on what looks best to you. Here is an example of a high dynamic scene:
When do you need dynamic range?
Generally speaking, you need dynamic range if you shoot:
- with the sun inside your picture.
- citylights at night
You don’t need dynamic range if you shoot:
- in a studio (you control the light)
- on overcast days (equal lighting in your image)
- landscape with sun behind your back (light falling evenly on scenery)
Most cameras with a large enough sensor (APS-C / DX or upwards) since about 2013 have plenty DR for most circumstances.
Here’s another example:
Capturing the most dynamic range
You get the best dynamic Range at base ISO (ISO 100 on most cameras). Be aware of „fake“ low ISO’s. Some cameras artificially create ISO’s of 50 or 32 (sometimes marked as Low-1 oder Low-2). These are regular ISO 100 exposures in which the camera applied exposure compensation to darken the image after its taken. These „fake“ ISO’s do not provide additional dynamic range.
If shooting from a tripod, you can capture as much dynamic as possible by bracketing. Bracketing means taking several images at different exposures covering the whole brightness of your image.
A bracket with only two exposures at 0,-2 exposure compensation will enhance your DR by 2 stops. With bracketing even the most basic camera with poor DR can record incredible amounts of dynamic range.
I prefer to only bracket 2 exposures. One exposure for the shadows and the second at -1 or -2 for highlight recovery. This covers most of my dynamic range needs, keeps editing simple and lowers the likeliness of trouble when combining the different exposures into one image.
Dont overdo it. A picture still needs light and dark areas. Else it will be flat.
How much dynamic range (DR) do you need? Every camera reviewer measures dynamic range differently. Only compare cameras measured by the same reviewer.
Generally speaking: Nikon DSLRs have the best dynamic range you can get. Sony and Fujifilm are close while Micro 43 cameras are a little more behind. Canon only recently started catching up with the 5D Mk IV and 80D after being behind for years.