Datavideo SE-1200MU, Инструкция по эксплуатации

Страница: 41 / 60

41
Chapter 8 CHROMA Key Functions
8.1 Overview
The Chroma Key feature of the SE-1200 MU is
easy to use. Typical Blue and Green screen
studios can be quickly incorporated into an SE-
1200 MU production.
The following is a quick overview of Chroma Key
basics.
The camera , backdrop and lighting all play an
important role in producing the optimal
Chroma Key result. Although the SE-1200 MU is
equipped with excellent keying controls, it is
best to start with a good keyable image.
A good foreground image helps produce a good key
Three chip/Three sensor camera
We strongly recommend the use of a three chip or three sensor camera for Chroma Key shooting. If the
camera has three chips or sensors then this usually means good colour separation within the camera. The
optics on these cameras are usually better too. The extra image clarity and the good colour separation help
improve the quality of the subsequent keying with the camera’s output.
White Balance the Camera
White Balance is extremely important after setting up a chroma key studio. The camera must be correctly
white balanced to minimize the subject picking up any colour cast (green or blue) from the
background. Of course the white balance settings will vary according to the type of lighting you are
using, but neutral whites and good skin tone colour are the all-important targets.
To set the white balance you will need a white reference card (or a sheet of white paper). Focus the
camera on the reference card and light it evenly using the main light. Set the camera’s iris / aperture so
that the card is correctly exposed. Use the Auto White Balance (AWB) function, or set the white balance
manually so that the card appears white. If you are in any doubt about how to white balance your camera,
please refer to your Camera’s instruction manual for more details.
Lighting
Lighting of your chosen green or blue backdrop is extremely important; the more even the lighting on the
backdrop the better the finished result. Lighting setups for the foreground subject will vary according to
the effect that you want. For chroma keying backdrops, balanced even lighting, with no hotspots or
shadow areas is the aim. The easiest way to achieve balanced Chroma key lighting is with a lighting setup
that looks similar to this: