Physical Camera Attributes

The V-Ray Physical Camera attributes apply real-world camera settings such as f-stop, focal length, and shutter speed to set up the virtual CG camera. It also makes it easier to use light sources with real-world illumination, such as V-Ray Lights with physical units or V-Ray Sun and Sky.

There is a quick setup button in the V-Ray Menu, which creates a Blender camera and adds Physical Camera attributes to it automatically. Otherwise, you can manually create a camera and enable the attributes yourself.

UI Paths:

||V-Ray menu|| > Cameras > V-Ray Physical Camera

||default Camera|| > Data menu > V-Ray Physical Camera

Camera Type – Specifies the camera type. This mostly has an effect on the motion blur effect produced by the camera. Different options are available depending on the camera Type.

Still – Simulates a still photo camera with a regular shutter.
Movie – Simulates a motion-picture camera with a circular shutter.
Video – Simulates a shutterless video camera with a CCD matrix.

Specify Field of View – When enabled, sets the field of view directly without having to set up the Film Gate (mm) and Focal Length (mm).

Field of View – Specifies the field of view in degrees.

Film Gate (mm) – Specifies the horizontal size of the film gate in millimeters. Note that this setting takes into account the system units configuration to produce the correct result. Vertical film gate size is calculated by accounting the image aspect ratio (vertical film size = horizontal film size/aspect ratio). 

Focal Length (mm) – Specifies the equivalent focal length of the camera lens. This setting takes into account the system units configuration to produce the correct result.

Zoom Factor – Specifies a zoom factor. Values greater than 1.0 zoom into the image; values smaller than 1.0 zoom out. This is similar to a blow-up rendering of the image.

Film Speed (ISO) – Determines the film power (i.e. sensitivity). Smaller values make the image darker, while larger values make it brighter. This option is not available for V-Ray GPU. See the Cheat Sheet for more information.

F-Number – Determines the width of the camera aperture and, indirectly, exposure. If the Exposure option is set to Physical Exposure or Exposure Value, changing the F-number affects the image brightness. See the Cheat Sheet for more information.

Shutter Speed (s^-1) – Specifies the shutter speed, in inverse seconds, for the Still Camera Type. For example, a shutter speed of 1/30 s corresponds to a value of 30 for this parameter. See the Cheat Sheet for more information.

Shutter Angle – Specifies the shutter angle (in degrees) for the Movie Camera Type.

Shutter Offset – Specifies the shutter offset (in degrees) for the Movie Camera Type.

Latency (s) – Specifies the CCD matrix latency (in seconds) when the Camera Type is set to Video. This option is not available for V-Ray GPU.

Exposure – Specifies how the F-number, Shutter Speed (s^-1), and Film Speed (ISO) settings affect the image brightness. 

No exposure – Shutter Speed (s^-1), F-Number and Film Speed (ISO) settings do not affect the image brightness;
Physical Exposure – Image brightness is controlled by the Shutter speed (s^-1), F-Number, and Film Speed (ISO);
Exposure Value – Uses the Exposure Value to control image brightness. Grays out the ISO parameter and uses the Shutter speed (s^-1) and F-number values only for Motion Blur and Depth of field, respectively.

Exposure Value – Controls the exposure value when the Exposure Value option is selected.

Vignetting – When enabled, simulates the optical vignetting effect of real-world cameras. The strength of the vignetting effect can be specified, where 0.0 is no vignetting and 1.0 is normal vignetting.

White Balance – Allows additional modification of the image output. Objects in the scene that have the specified color appear white in the image. Note that only the color hue is taken into consideration; the brightness of the color is ignored.

Vertical Tilt – Vertical tilt that allows the simulation of tilt lenses for a 2-point perspective.

Horizontal Tilt – Horizontal tilt that allows the simulation of tilt lenses for a 2-point perspective. Changing these parameters is similar to applying a camera correction modifier. 

Vertical Shift – Vertically offsets the camera field of view as a fraction of the current view. For example, a value of 0.5 offsets the camera by half of the current image height in an upward direction.

Horizontal Shift – Horizontally offsets the camera field of view as a fraction of the current view. For example, a value of 0.5 offsets the camera by half of the current image width to the left. 

Depth of Field – Enables the depth of field effect. Note that depth of field depends on the F-Number parameter.

Aperture Shape – Defines the shape of the camera aperture. When disabled, a perfectly circular aperture is simulated. When enabled, a polygonal aperture is simulated, with the specified number of blades.

Blades Number – Specifies the number of blades of the aperture.

Rotation – Rotates the blades (value in degrees).

Center Bias – Defines a bias shape for the bokeh effects. Positive values make the outer edge of the bokeh effects brighter; negative values make the center of the effect brighter.

Anisotropy – Allows stretching of the bokeh effect horizontally or vertically to simulate anamorphic lenses. If you want the ratio of height to width of the bokeh to be k:1,  then the value for Anisotropy should be √(1/k)-1. For example, for anamorphic bokeh, which is 2.39:1, the Anisotropy value should be -0.353. 

Optical Vignetting – Controls the strength of the optical vignetting, also known as and cat's eye vignetting. This effect is due to the fact that the shape of the bokeh highlights resembles the shape of the aperture. As the distance to the optical axis increases, the bokeh highlights are progressively narrowed and begin to resemble the shape of a cat's eye. The larger the distance from the image center, the narrower the cat's eye becomes. Optical vignetting tends to be stronger in wide-angle lenses and large aperture lenses, but the effect can be noticed with most photographic lenses.

Bitmap Aperture – Enables the use of an image (specified in the field below) to control the aperture shape, as well as any dirt or scratches that may affect the bokeh. White signifies transparent areas and black signifies opaque areas.

File – Specifies the image file.

Bitmap Resolution – Specifies the sampling texture resolution when calculating the bokeh effects.

Affect Exposure – When enabled, the bokeh effects affect the overall exposure of the image.

Type – Specifies how the distortion is determined.

Quadratic – The default distortion type. It uses a simplified formula that is easier to calculate than the Cubic method. 
Cubic – Used in some camera tracking programs like SynthEyes, Boujou, etc. If you plan on using one of these programs, this distortion type should be used. 
Lens File – Uses a .lens file, which is specified in the Lens File field. 
Texture – Uses a texture file, generated in a third-party application (i.e. Nuke), and specified in the Distortion Texture field.

Amount – Specifies the distortion coefficient for the camera lens when the Distortion Type is set to either Quadratic or Cubic. A value of 0.0 means no distortion; positive values produce "barrel" distortion, while negative values produce "pillow" distortion. See the Distortion example below for more information.

Distortion Texture –  When the Distortion Type is set to Texture, this slot specifies the color that determines the distortion, or the map that contains the distortion data. This option is not available for V-Ray GPU.

Lens File – When the Distortion Type is set to Lens File, this slot specifies the lens file, containing the distortion data.