High Dynamic Range In
Digital Photography
By: Amy Renfrey
 If
you have ever wanted to improve your digital
photography then you may want to consider learning
about High Dynamic Range. If you have heard of this
term in digital photography, but are not sure what
it is, then keep reading because it will serious
change the way you look at your digital photography
images. What High Dynamic range does in your digital
photography is simultaneously lighten your
underexposed areas and darken your overexposed
areas. Working with your Dynamic Range will aim to
create digital photography images as your own eye
would see them; even light all over the scene.
In the digital photography world Dynamic Range
simply refers to the range of light (luminance)
vales from the darkest to brightest. In the real
world is really the range of dark to bright sections
of light that you can see with the naked eye. This
is transferred to digital photography and it given
the name Dynamic Range. Digital Photography Dynamic
Range is the range of light on your digital camera
sensor that can be captured without having the
higher light or lower light values altered or
edited. In digital photography speak High Dynamic
Range simply means a higher range of light values.
You will notice that after understanding Dynamic
Range that your digital photography can be improved
dramatically and, very fast. Digital photography
Dynamic range can improve aspects of your image such
as adding a sense of drama to your cloudy
landscapes, giving detail to lines of colour, toning
down some overexposed parts of light sections of a
digital image.
You may find that when photographing things outdoors
in your digital photography such as landscapes,
beach and snowscapes etc, you have a lot of
contrasting highlights that slow your progress down.
To overcome sections of high contrast you can use ND
filters, a polariser, exposure bracketing, post
editing in Photoshop etc, etc, the list goes on what
you can do in digital photography but really, to get
a more accurate exposure working with your Dynamic
Range will be more effective.
You can get a good idea of digital photography
Dynamic when you go outside and look at the light.
For example High Dynamic Range is the bright
sunlight on a typical outdoor, sunlit scene. In
saying that, a Low Dynamic Range may correspond to
darker areas such as a dimly lit room.
 Let’s
take my Sony digital camera to use as an example. It
has 6 stops of Dynamic Range. The Dynamic range’s
objectives are to capture more dynamic range. While
it’s easy to capture daylight scenes with the Sony,
in some instances like landscapes, more Dynamic
Range might be needed. So in this case producing my
High Dynamic Range requires that I take some
separate exposures. Then I place all of the
brightness levels that I want in my final image that
my Sony’s sensor can record properly. What this
means is putting the darkest values no lower than in
the mid-range of the sensors light sensitivity
range.
In the wonderful Adobe Photoshop I may decide to
take a handful of exposures to cover the complete
dynamic range. In each photo exposure I keep the
aperture the same (changing aperture changes the
depth of field). My aim here is to create different
photos making sure that in each I cover the
available brightness levels in the landscape.
I take a collection of photos of my landscape at
about 1 stop changes in each photo. I don’t do this
by altering the f stop I do this via my shutter
speed. To check whether I’ve got variation in my
exposures I can check the histogram to see whether I
have adequately captured the scenes brightness.
Once I have all my exposures in the camera I go home
and check it out in Adobe Photoshop. What I should
be able to do then is edit them and create a picture
as my own eye would see; good lighting on the
foreground and good lighting on the background,
without over exposure of the sky or underexposure of
darker parts of the land.
Have fun and happy shooting!
Amy Renfrey
If you are serious about creating superb, sharp and
clear images just go to
http://www.digitalphotographysuccess.com/.
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