Wednesday, May 13, 2009

What is HDR?

HDR, short for High Dynamic Range, is a technique used by photographers to get the “right exposure” of a photo from a set of differently exposed photos.  Ok, ok … what the heck for and is the word “right exposure” the right term?

Most cameras (and in fact, the human eye as well) are not able to capture the whole range of light that exists in the real world.  By combining various photos of varying highlights, mid-tones and shadows, an image of higher dynamic range can be achieved.  Typically a range that’s about 2 times.

A good example can be found at the photomatix website where they showed a set of picture taken from dark room with a window to the bright outdoors.

photomatix-example

As can be seen from the 5 different exposures, it is almost impossible to get a balanced exposure for the picture.  If metered on the outdoors, you will get an underexposed interior shot but if metered on the interior, you will get an overexposed exterior shot.  HDR helps to give a more dynamic range.  I like this particular example as I believe it gives us a clear explanation though pictures.  A picture is as good as a thousand words, some say …

4 comments:

kuanhoong said...

Next time you can showcase your own HDR photos

Durian Guy - Malaysia said...

Does all digital camera has this HDR feature? Do we need a software to combine the pics? Why 5 pics? My camera is a cheap Canon IXUS 970IS. :) Guess i'm not allowed to ask question, eh.

Neutral life said...

Durian Guy - No, most digital camera can't do HDR automatically (except the very recent Sony?). U need a software to combine those pics. 5 pics for 5 different exposures. If possible, use tripod as well bcos u need to take 5 pics with the same composition.

Ian Tan said...

Thanks neutral ... ya, new Sony HX1 says it can combine a few shots but I also doubt it is HDR.