Color Frame Accessories
There are several devices that can be placed in the color frame of a lighting instrument that can affect the shape of the light.
- Barn Doors are used to cut the edges of the light for non-ERS instruments which do not have shutters.
- Top Hats, Half Hats and Eyelashes help to control the ambient light that is given off by a fixture, and/or help to reduce glare in the eyes of the audience.
- Donuts are effectively a solid gel frame with a smaller hole which help to sharpen gobos and reduce chromatic aberration on sharply focused ERS fixtures.
Barn Doors
The Barn Door fits into the color frame of Fresnel and PAR type instruments. Typically the unit has four hinged flaps that can be adjusted to roughly cut unwanted light off of scenery, soft goods, etc. The cut isn't quite as sharp as you will find with ERS shutters, but it does the job fairly well.
Barn Door units are very heavy, and usually have a safety chain attached. This safety chain should be attached to the yoke of the instrument, just in case it is to fall during installation, strike or during the production run.
Barn Door units are very heavy, and usually have a safety chain attached. This safety chain should be attached to the yoke of the instrument, just in case it is to fall during installation, strike or during the production run.
top hats, etc.
When gel or frost are placed into instruments, some ambient light is reflected and scattered away from the intended target, sometimes onto walls, soft goods or the audience. A great way to control this scattering is to install a shade, or Top Hat. This device slides into the gel frame in front of the color, and acts much like a baseball cap visor to keep the light from scattering in the wrong direction.
This is particularly useful in front of house hanging positions, where the use of frost often will light up the whole house because of the light-scattering properties of the media. By putting a Top Hat in the instrument, the light on the stage is not affected significantly, but the ambient light in the rest of the space is greatly reduced. Depending on the placement of the instrument, sometimes a little ambient light is OK, but one side only needs to be shaded (such as if the ambient light is spilling on a border). In these cases, a Half Hat might be appropriate. |
donut
In addition to being a tasty treat to eat on coffee breaks, a donut is also a device to help to sharpen gobos. The optics of the ERS instrument are very good, but occasionally when an extremely sharp gobo edge is desired (such as for text or very specific imagery), the edge of the image continues to have some imperfection. Additionally, sometimes the edges of the light will have a bit of a rainbow effect due to the optics of the lens, as the edge of the lens acts somewhat like a prism. This is called chromatic aberration, and can be solved by reducing the aperture of the instrument. This is achieved by placing a donut in the gel frame with the color frame. Because Physics.