JVC DLA-X70R, DLA-X30, DLA-X90R, DLAX70 manual Operation guide glossary, Gamma Curve, 100%

3 Operation

Operation guide (glossary)

Gamma Curve

The description of the gamma curve that assumes a gamma curve unit. Please read the relevant detailed description and professional books.

The gamma curve of the projector to the input video signal determines for each color the relative value of its light output.

The value of the input video image signal is displayed as a percentage - with	100%
both being displayed in % as units - of the maximum light input signal for bright-
ness and the brightness output value as a percentage of the maximum output	output
value of each color or the projector. In relation to the signal value of 50% of the
input, it projects with brightness output value of 50%. However, a light output			50%
value of 0% is not completely black and neither no projection. As the possibil-	light
ity of the projector to reproduce blackness is limited, it will be actually slightly
brighter.	The
The input video image signal value becomes a continuous curve of 0% to 100%
for the gamma curve, which can be set with the projector. Moreover, it is impos-	0%				50%
sible to get only one light output value for the input video image signal value.
		0%		Input	signal	100%
The gamma curve can be set for each color, i.e. red, green and blue. By select-
ing the white color, the 3 colors can be adjusted at the same time.				value
A larger angle of inclination of the gamma curve leads to a greater gap of the

light output value of that area and makes it easier to distinguish the video images. A low angle of inclination leads, on the contrary, to the difference in that area becoming smaller, so that the video images are harder to distinguish. If it is im- possible to get an inclination angle, so that it is chosen to become horizontal, the gap in that area vanished and it might be impossible to distinguish the video images.

100%

The light output

0%

0%

A		A	B	C
	B
	C
Input sig-
	100%
nal value

Suppose you knew the inclination of the input video image signal values of the watched video images, and would increase the slope of the portion of this area and attenuate the slope of other areas. It would then be easier to determine the video images. Also, if you did not know the inclination of the input video image signal value of the watched video images, adjustment would be difficult.However, there are some trends of the distribution of the input video image signal value depending on the type of video content. As some typical examples are prepared in the [Gamma] (Reference Page: 54), it is recommended to perform similar settings before watching.

Some methods about how to adjust the gamma curve are presented here, but in reality one can think of various adjust- ment methods, for example where red, green and blue are individually adjusted. In your own image creation, please

enjoy the process of trial and error.

100%
The light output
0%
0%	Input sig-	100%
	nal value

100%
The light output
0%
0%	Input sig-	100%
	nal value

The distribution of the input signal The distribution of the input signal

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