Sony 900, 930, 950 manual Camera characteristics

9	Scene file	camera setting data made during rehearsal can be
	A scene file is a place to temporally store the data that	stored in a scene file and then be recalled during an
	differs from the normal settings. For instance, a	actual take.

9-3.Camera characteristics

Most of the camera characteristics cannot just be determined by numbers. Good values do not always equal good picture quality. Judging by human eyes is one of the most important processes to evaluate a camera. The following are a few technical terms to be familiar with:

Modulation depth

Modulation depth is used to measure a camera’s fundamental performance. It shows a video level percentage of a 0.5 MHz pulse wave in a subject so that the 0.5 MHz pulse wave video level is 100% as black to white, by shooting a Multi Burst chart while Detail, Gamma, Matrix and Knee are off. The camera’s performance is calculated by measuring the 0.5 MHz response in the actual video bandwidth. Usually, the frequency characteristics of the amplifier should be kept flat, because if the level is raised too high, aliasing noise will increase and the S/N becomes worse. In actual shooting, picture quality is adjusted by adding Detail signals to enhance the response.

Power consumption and heating

Power consumption is a factor that develops heat, which is critical for shoulder-operating production cameras although it is a little bit relaxed for studio cameras. Using a cooling fan to reduce heating is not a good solution, because the camera operator can hear this noise. So, low power consumption is an essential factor.

Reliability

Reliability is one of the most important factors when we evaluate a camera. Unlike other broadcasting equipment, cameras are often used outside under severe circumstances such as live broadcasting of skiing events below the freezing point or live broadcasting of baseball in mid-summer, where reliability always has first priority and a camera malfunction is not acceptable.

Resolution

When we are talking about camera resolution, it usually means horizontal resolution. It is calculated on how many black and white lines that you can see horizontally in a subject to that of the black and white lines counted independently. For instance, a black line and a white line are counted as two lines. When it is converted to vertical resolution, because the definition is how many lines can be seen vertically, it should be revised with the aspect ratio. Therefore, even though the horizontal pixel number is the same; resolution of 4:3 is better than that of 16:9.

Since the video signals of most of the cameras are processed digitally, the resolution limit is fixed; this is why the modulation depth has become to be regarded as more important.

S/N (signal-to-noise ratio), Sensitivity and dynamic range

When we are talking about camera S/N, it usually means the S/N of black. The black level is amplified by gamma and its gain greatly affects the S/N, which vary between different manufacturers and even - different models from the same manufacturer. Of course, users also have different tastes. S/N is also changed by

different DTL settings. Usually, it is measured when IRIS is closed, gamma is off, DTL is off, Chroma is off, and the pedestal level is set at 5%.

There is a close relationship between S/N, sensitivity, and dynamic range. When we raise the sensitivity, the S/N and dynamic range will decrease. So, it is difficult to decide to emphasize which item while the other two items will be affected. Although the measured value of the S/N is important, it seems that the S/N judged by human eyes after gamma and DTL are set is more important.

Weight and balance

Very naturally, less weight is better for shoulder- operated equipment. However, balance is also a very important factor. If the camera weight is too low, then the overall balance of the camera will be off when a large lens is attached.

HDC-900/950/930 Series Product Information Manual Chapter 9 Glossary – Terms and Definitions 176