VRay for SketchUp Manual
Depth of Field
What is Depth of Field?
Depth of field refers to the amount of an image which is in focus and the
amount which becomes blurry. In photography it is impossible to have every part
of an image in perfect focus. Because of this a photographer chooses what will
be in focus and what will not. Within V-Ray this will correspond to the focal
distance. The amount in which an object is out of focus depends on how far
away it is from the focal distance of the camera as well as the size of the
camera’s aperture. A small aperture will have a only a slight amount of
blurriness for objects which are not within the focal distance. A large aperture
will have a large amount of blurriness for objects outside the focal distance.
Open V-Ray for SketchUp’s Render Options. Pull down Camera control menu and
you will see the big item of Depth of Field below. Default is set to off, check it
if you want to have Depth of Field in the final rendering. Depending on the
way your camera is set up you may want to check Override focal distance. With
out this setting enabled V-Ray will use the focal distance of the camera.
How to find out the current setting of focus distance of the camera?
1. Open file
Chairs-DOF.skp. You will see the image below which shows the distance
between the chairs. Please note the distance between the camera and the chair in
the center which is 67’ away. This is the number we need for the override focal
distance, which is 800. (800 inches = 67 feet).
It is important to note that the exact location of the camera was identified with ruby
script "Note Camera Point" from www.smustard.com website.
Image on the top is rendered without Depth of Field and image on the bottom
is rendered with Depth of Field.
Size of Aperture
There is Aperture located at the top of the control panel for Depth of Field
under Camera. V-Ray doesn't use the same number unit of F1.4 F2.0 F11 as the
normal camera does to control the amount of light that comes into the camera.
Instead, it uses
the system unit for its size. Smaller numbers have less effect on Depth of
Field. Larger numbers will make the object very blurry and takes a longer time
to render, especially when calculating the edge of object for Depth of Field
effect. So we recommend you start with a smaller number and move your way up if
you need a stronger effect. This scene’s aperture was set to 24. I recommend you
try different values and see what results you get.
Below are some images showing more examples of Depth of Field.