Explanation: „High Dynamic Range“ means to combine several pictures, taken with different exposures, into one. Doing so over- or underexposed parts of one image can be replaced by correctly exposed ones of another image.
As a result a higher range of contrasts can be shown in the final image than with only one exposure.
Active D-Lighting and HDR have the same objective but use different methods to achieve it:
- ADL uses additional logic when creating a JPG image from the RAW data of the image sensor and possible a slight exposure compensation.
- HDR takes several pictures with completely independent exposures and merges them into one.
The implementation of HDR at the D5100 is as follows:
- Before each HDR picture you have to activate this feature in this menu by setting „HDR mode“ to „On“.
When pressing the shutter release button the next time the D5100 will take two pictures and switch HDR off again.
- The second menu entry „exposure differential“ defines if the exposure difference between the two images is set automatically or a certain number of exposure values that you choose.
- The last entry „smoothing“ determines how much the transition between parts from the two images should be hidden by a kind of unsharpening.
Recommendation: HDR works well. If you have a subject with really high contrasts it can improve your pictures more effectively than ADL can based on just one exposure..
Leave the settings for „exposure differential“ and „smoothing“ with the predefined values „auto“ and „normal“.
If you want to use this function regularly you can assign it to the Fn (function) button in the menu f1 Assign Fn button and activate it anytime with a single push there.
Use HDR only with matrix exposure metering.