Tutorial
#16 - Correcting Underexposure
| Whether we like it or not, sometimes when we take
a photograph, especially like the scene above where the
digital camera has taken a reading from the sky, which,
in turn, under-exposes the foreground.
By using Photoshop, we can easily rectify this
problem:
The image shown here was typical
of getting too much cloud and sky in - resulting in the
foreground lacking in light - the lack of light happened
because I had too much light from the sky - remember to
watch where the sun is when composing your shots. |
-
The first thing we need to do is create a duplicate copy of
our image. Select the Duplicate command from the Image menu
and give it a new name.
-
With our new image active, choose the Desaturate command from
the Image Adjust menu - this will drain all the colour.
-
Ok, we need to blur the image, but not so much as we lose vital
detail within the image. From the Filter menu, choose Blur and
then Gaussian Blur. In the value settings box, enter a value
of somewhere around 4.5 to 6. Click on OK when you are happy
with your settings.
-
We now need to select the under-exposed areas - Get the Magic
Wand tool from the Tool Box and click anywhere on the dark areas
you want to fix.
You can now either hold down the Shift button and add more
of the dark areas to your selection, or you can choose the Similar
command from the Select menu.
-
When you are happy with your selection, choose the Save Selection
command from the Select menu - by doing this we can load the
selection onto our original image.
-
Switch back to the original under-exposed image. Load the previously
saved selection by choosing the Load Selection command from
the Select menu. You should now see the marching ants (selection)
around the dark areas of the image.
-
Now for the magic act! From the Edit menu choose the Fill command.
Enter the settings opposite and press OK
Hopefully you should now have cured an under-exposed image!
This technique will also work on over-exposed images
- all you need to do is select the lighter areas rather than the
dark ones and choose Color Burn command instead of Color Dodge.
|
BreBru.com
