form•Z | Render Options | Camera

Camera Tab

Maxwell Render renders the active form•Z view. To construct a Maxwell camera, the plugin obtains the eye point, center of interest, and focal length from the the form•Z View Parameters (double-click on a view in the views palette). The resolution and pixel aspect ratio are obtained from the Camera View settings in View Parameters if these are in use; if not, the values specified in Display > Image Options... are used instead.

The Maxwell simulates a number of additional properties of physical cameras, and as such requires several parameters not found in form•Z. These are specified though the Camera Tab. The options here will apply to all views/cameras rendered within the associated window. Maxwell Render options are also stored on a per-scene basis, so if you need a different set of camera parameters, create a new form•Z Scene in the Scenes palette.

Exposure

• EV Lock: When enabled, the current exposure is maintained when adjusting the f-stop, shutter speed, or ISO. If the f-stop is adjusted, the shutter speed value will be adjusted to compensate, and vice versa. If the ISO is adjusted, the shutter speed will compensate.

• f-Stop: Specifies the diameter of the lens opening, or aperture, as an f-Stop value. Clicking on the triangle to the right exposes a menu of traditional f-Stop values in third-stop increments. Arbitrary values can be typed into the text field. Aperture size also affects not only image exposure, but Depth of Field (DOF). See Camera.

• Shutter: Specifies shutter speed, indicated as a fraction of a second. Clicking on the triangle to the right exposes a menu of traditional shutter speed values in third-stop increments. Arbitrary values can be typed into the text field. This parameter may be adjusted interactively in Maxwell while rendering.

Sensor

• Sensitivity: Specifies the sensor’s sensitivity to light, as measured by the ISO arithmetic scale. Clicking on the triangle to the right exposes a menu of traditional ISO ‘speeds’ in third-stop increments. Arbitrary values can be typed into the text field. This parameter may be adjusted interactively in Maxwell while rendering. The lower the ISO value, the less sensitive the sensor, requiring a more exposure to light (or stronger emitters) to achieve a satisfactory exposure. Conversely, higher ISO values require less exposure to light to achieve the same exposure. In the real world, the sensor may be photographic film or a digital CCD; in Maxwell, the sensor is virtual. This means that, unlike in the real world, raising the Maxwell ISO will not add noise to the render.
• Film Back
  • Automatic: Selecting this option will cause the plugin to calculate the appropriate film back size to match form•Z ’s focal length setting. Selecting this option will always result in a correct field of view match between the form•Z viewport and the resulting Maxwell render. form•Z ’s focal length setting always assumes a 36mm wide film back, emulating the use of 35mm film in an SLR camera. The automatic option adjusts the film back height to match the aspect ratio of the pixel dimensions. For instance, a 500 x 1000 pixel image will be assigned a 36mm x 18mm film back, while a 1000 x 500 pixel image will result in a 36mm x 72mm film back.
  • Manual: Selecting this option allows for manual control over the size of the film back. The left parameter is the x (width) of the film, the right is the y (height). In millimeters.

Diaphragm

• Circular / Polygonal: The diaphragm is the camera mechanism responsible for adjusting the size of the aperture. This option specifies whether the diaphragm is polygonal or circular. If set to polygonal, it will consist of a number of strait blades arranged in a circular pattern which are shifted to increase or decrease the aperture’s diameter. The diaphragm’s geometry determines the shape of out of focus light in the rendering, a phenomenon known as the bokeh effect. The bokeh effect is most pronounced in images with a shallow Depth of Field, particularly around small highlights in out of focus areas, such as light distant sources or specular reflections. See Camera section - Bokeh for more details.
• Blades: Specifies the number of blades when a polygonal diaphragm is used. A diaphragm with six blades will produce typical hexagonal bokeh aberrations. A greater number of blades (or circular diaphragm type) will result in a more circular bokeh effect, but will require more render time.
• Angle: Specifies the blade rotation angle in degrees (for Polygonal diaphragm). Rotating the angle of the blades will result in the polygonal bokeh shapes changing their general orientation.

Shift Lens

Adjusting the y-shift (rise) is useful in architectural rendering to eliminate converging parallels in tall buildings, approximating a two-point perspective. See Shift Lens.

• Horizontal: Specifies the horizontal shift of the film plane relative to the lens, as a signed percentage (-100% to 100%).
• Vertical: Specifies the vertical shift of the film plane relative to the lens, as a signed percentage (-100% to 100%).