physical_camera

#Physical Camera

A typical Renderman camera will export an image with optional depth of field and motion blur, but none of the other artifacts and visual anomalies that a real camera would have. Typically these effects would be added in a compositor or image editing tool. As of Renderman 20, a new physically based camera model was introduced that can create many of these effects during the actual render, negating the need to post process the image.

Some of the effects the physical camera can display are:

• Chromatic Aberration. This is a slight spatial misalignment of the red, blue and green wavelengths as they strike the image surface. It is typically caused by inexpensive camera lenses and is most visible near the edges of the image and in out of focus areas.
  
• Vignetting. This is a slight darkening of the image edges due to lens artifacts or the shadow cast by a lens hood.
  
• Lens Distortion. This is an image distortion that is created by the lens of the camera. In severe cases it can cause straight lines to appear curved and completely alter the proportions of an image.
  
• Shutter Artifacts. A camera shutter can be either a global shutter (entire frame is scanned at once) or a rolling shutter (image is scanned one line at a time). Rolling shutters are common on digital cameras and can introduce a specific 'leaning' image distortion on fast moving objects. This happens because the moving object has changed position between the beginning of the line by line frame scan and the end.
  
• Tilt Lens. Tilt lenses are commonly used in architecture photography and allow a picture to be taken looking 'up' without the normal vanishing point distortion that angle causes.
  
  Descriptions of the camera parameters and what they control can be found in the official Renderman Documentation

Example Photos:TODO