Knoll Light Factory 3

List of Built-in Elements

Built-in Elements are flexible light objects that you can layer to build up a lens flare design.

In the Lens Designer, you choose the Built-in Elements from the Elements Panel. Make sure to read about the Element Controls that modify Built-in Elements.

Aperture Reflection

Most film cameras will exhibit some aperture reflection. In a film camera, the film passes through the movement, where it is exposed to light. The movement has a rectangular hole called the gate. The focused image from the lens shines through the gate and onto the film. In most cameras, this aperture is polished stainless steel, and is highly reflective. When the focused image of a bright light gets close to or slightly outside the edge of frame, the image can reflect off of this shiny surface back into the image causing an aperture reflection.

NOTE: To see the effect, the light source location must be outside the edge of the frame.


Barrel is a reflection that occurs between the surface of lens element and the inside barrel of the lens. The more air/glass interfaces in a lens, the more light that will potentially be reflected. Modern zoom lenses often contain a large number of individual lenses inside their barrels.

Chroma Fan

Chroma Fan generates a rainbow diffraction patterns. These patterns often appear when a net is used for diffusion over the lens, or when there is fog or mist in the air.

Chroma Hoop

Chroma Hoop creates a circle of rainbow lines that streak through the center of the light source. This type of effect is frequently seen on film shot in Super35 format.

Circle Spread

Circle Spread lets you create a number of randomly sized and positioned circles. The controls are similar to those in Polygon Spread. Circle Spread is useful for making the tiny dots and small circles that appear in lens flares.


Disc gives you precise control over the generation of a single circular ramp effect. It has three separate controls for the inner, middle and outer gamma. It also has taper and center offset controls that change the shape of the disc.


Ellipse is like Disc, except that its shape is elliptical, not perfectly circular. In general, the glow at the light source is circular, and reflected elements are elliptical.

Elliptical Caustic

Elliptical Caustic simulates a unique distorted reflection that is found primarily in Nikon still camera lenses.

Fading Ring

Faded Ring generates a 'rainbow ring' effect that fades out toward the edges of the frame.

Glow Ball

Glow Ball is a basic primitive used in most flares and effects. The glow represents the overexposure and light scattering that a bright light source creates when focused through a lens onto an image plane. You can control the color and scale of the glow, as well as the rendering of a characteristic red ring associated with a bright light source.


This is not actually a lens flare element! The Guides places a grid and position/orientation marker on the flare preview.

Horizontal Spread

Many anamorphic lenses exhibit streaks around the center of the lens. Horizontal Spread renders several tapered lines with adjustable color, brightness, position and spread.

Image Sprite

Image Sprite lets add your own image as the light effect source. A Browse window lets you choose any bitmap file, like JPG or PNG. It's a way to bring in a flare element that you've created and use it for your lighting effect.

EverySprite has an Image Sprite control. The Image Sprite element is simply a solo way to import your custom sprite, and it will display the name of the file that you've imported. Image Sprites and Sprites have the same controls available.

Lens Texture

Lens Texture is an easy way to add fake grime to your lens flare. This element adds to the overall realism of the effect because it simulates grime on the camera lens that is reflected in the flare. The texture is applied to the whole frame, but its default settings only illuminate the brightest areas of the light effect.

Photon Spike

As the name implies, this effect generates the 'Photon torpedo' effect from science fiction films that creator John Knoll has worked on over the years.

Poly Spike

The polygonal opening of a bladed aperture can cause many polygonal reflections to appear on the exposure surface. Polygon Spread creates a number of randomly positioned polygonal reflections, each with a different brightness and random hue. Since these reflections are created randomly, there are three different random seeds used to vary the look.

NOTE: There is a relationship between F-stops, polygonal reflections and star filters. A lens that is ‘wide open’ (F-stop set to its minimum value) usually exhibits circular reflections. As the aperture closes down, the shape of the aperture changes the reflections to polygon shapes, and a ‘star filter’ usually appears at the source.

Random Fan

Random Fan generates an attractive asymmetrical fan of spikes with many radial lines. RandomFan responds to the angle control with a subtle shimmering of the lines.

Rectangular Spread

Many anamorphic lenses exhibit streaks around the center of the lens. Rectangular Spread generates horizontal bars which emulate that effect.

Single Poly

The Single Polygon filter is appropriately named with complete controls for generating a single polygon shape. You can control the position, brightness, color, size, number of sides, softness, rotation, and the degree to which it varies in brightness as it moves from the center of frame to the edge.


Sparkle generates a number of short linear streaks radially distributed about the center. The streaks change with the angle control by appearing closer or farther from the center of the source location. The Unidirectional checkbox limits the motion to all inward or all outward (depending on what direction the angle control is moving). This effect can simulate the sparkle you see when a laser is pointed into a camera lens.

Spike Ball

Most lenses exhibit at least a little bit of radial streaking from the light source, and the Spike Ball simulates this. The lines in the Spikes appear as random lines from the center of the ball. You have control over the scale, brightness, density, color, rotation, and the random seed used to generate the spikes.

Star Caustic

This diamond-shaped caustic is useful for simulating reflections caused by reflective coatings. You will notice that the default values cause a barely visible green shape.

Star Filter

This version of Star Filter has been preserved to properly open legacy projects created with Knoll Light Factory 2.7 and earlier. For better results in new projects, please use Star Filter (new), which is explained below.

Star Filter simulates a common effect created by multiple bladed apertures. Most camera lenses contain multiple bladed apertures to allow more or less light to pass through the lens. This controls the exposure of the image. When the aperture is wide open, the opening is perfectly circular. As the lens is 'stopped down', the opening becomes a smaller polygonal shape.

For example, a five-bladed aperture will create an opening with five sides as the lens is stopped down. This is why you often see pentagonal or hexagonal shapes on a lens flare. The aperture also reflects light where the blades intersect, creating a star filter effect. A partially closed five-bladed aperture will reflect five streaks, for example, and result in a ten-point star on the exposed surface.

Star Filter

We created Star Filter (new) by revisiting the original Star Filter and shifted the draw pattern from lines to polygons. This gives you smoother more natural results with no rendering artifacts.

Otherwise, this Element behaves like the Star Filter, which is explained above, with some differences in their controls.


Stripe renders a tapered line with adjustable color, width, angle, brightness and position. Many anamorphic lenses exhibit a blue horizontal streak through the center, and some video cameras exhibit a reddish vertical streak through the center

Tilted Ellipses

Tilted Ellipses generates ellipses that are aligned with the center point of your lens flare. They emulate ellipses in photography that are caused by internal lens reflections on an object as it is picked up by the lens sensor.

Vertical Polyspread

Vertical Polyspread simulates the type of inter-reflections that occur between cylindrical elements of an anamorphic lens. This effect shows up most commonly on anamorphic zoom lenses. Zoom lenses typically contain many more lens elements than a prime lens, so the number of reflections is proportional to the complexity of the lens.