To begin this tutorial it is assumed that
you have a basic understanding of what HDR images are and their
importance as well as a basic understanding of how to use Tone-Mapping
Operators in Artizen. If not, please read What is
HDR tutorial and Using Tone-Mapping
Operators
The benefits of this operator is that Natural
gets the speed
of Display but with the Local functionality of Cipher without any of the
possible pitfalls of Cipher. One example of this is that when setting
the Halos option in Cipher to -1.0, it can sometimes produce very flat
results.
pre-tone mapped hdr from Sachform Technology HDRIbase
vol. 3
A common and simple approach to applying the
Natural operator usually
begins with setting the Strength value to approx. 0.5. Once this has been
done, there may still be some overly bright areas left. These can be
reduced by using the Highlights slider, but avoid over reducing the
Highlights as this could result in gray areas where white is
expected. At times this could be intended when used in conjunction with
Contrast, which will restore the gray areas back to white. The final step
is usually working with the Saturation option, which helps boost any dull
colors or helps create a more dramatic scene.
Local Controls
Strength: This option is the master control that determines the
amount of influence Radius, Details and Halos option have on the image. If
Strength is set to 0 than regardless of what Radius, Details and Halos
values are they will not impact on the image produced. 0.2 seems to be a
good initial value. Range (0.0 to
1.0)
Detail Radius: This option controls how sharp/soft the Shadows in your
image is with good initial values being between 0.5 - 1.0. If the value is
set very low the image appears to be flat cause the shadows virtually
disappear and blend into the the surrounding image. Setting this value
very high helps smoothen out the Shadows and Halos so that they blend more
smoothly into the image while preserving the overall contrast of the
image. An important note to make here is that the higher the value the
long this operator will take to process. Range (0.0 to 1.0)
Radiance: Since many tone mapping operators leave your image
rather flat, Lock06 uses this option to help soften the image by
distributing the Radiance. A good initial value is usually about 0.1 and
then increase as needed. Range (0.0 to 1.0)
Exposure
Gamma - This option is the standard way of
adjusting contrast in both displays and cameras but in a non linear
method. Most Displays have a gamma level of 2.2, but since there are
differences between gamma correction from device to device it is important
to be able to adjust this option. Range (0 to 4)
Brightness: This option controls the overall brightness of the
image and works similarly to a simple brightness color correction
tool. Range (-10 to 10)
Highlights: This option allows for fine tuning of only the
Highlights in an image. This is usually one of the last options to be
applied and
can be used for fine tuning while watching the histogram. If you need to
increase or reduce this value beyond +/-0.5 you should really consider
bringing this value closer to zero and then increase or decrease the
Brightness value. In other situations where not just the highlights need
to be adjusted the Highlights option in the Levels tool is very
useful. Range (-1.0 to 1.0)
Shadows: This option like the Highlights is for fine tuning only
the Shadows in an image. This option is also one of the last functions
applied to the image and is therefore very easily used in conjunction with
the Histogram. Once again the Shadows option in the Levels tool is
sometimes great to use instead of this option or in conjunction. Range (-1.0 to 1.0)
Color Balance
Temperature - This option enables users to adjust the overall
look of an image by changing the perceived temperature of a scene or
correcting the white balance of your image. Usually blue is considered
cool and red hot, but in nature the opposite is true. Range (-100 to
100)
Saturation - Controls the brightness of
colors in a photo, with -1 being a black and white image, 0 being
unchanged color level and 1 being colors boosted. Range
(-1 to 1)
RGB Adjustments - Similar to the Temp
and Hue options, these 3 options enable users to correct color shifts
and white balance but on a individual color basis since color shifts
don't always affect each color equally. Range (-100 to 100)
