Technicolor - Thomson LDK 100 manual Shooting Screens, Exposure Time, Clean Scan, CRT Exposure FT

Shooting Screens

Sometimes when shooting TVs or computer monitors a horizontal noise bar can be seen across those screens in the viewfinder. There are two ways of removing the noise bar from the picture depending on the frame frequency of the display. For displays with the same frame frequency as the camera, for example TV sets, use the V-shift facility. For displays with a higher frame frequency, for example computer monitors, use the Clean Scan facility.

Clean Scan

To use the Clean Scan function press the Clean Scan button at the front of the camcorder for about two seconds to directly access the variable exposure (clean scan) function. Use the rotary control to change the value and so remove the noise bar.

The ranges for FT cameras are:

from 50.6 to 103.1 for 50Hz cameras from 61.1 to 151 for 60Hz cameras

The ranges for IT cameras are:

from 50.1 to 103.1 for 50Hz cameras from 60.1 to 151 for 60Hz cameras

When you are finished shooting the monitor press the Clean Scan button for two seconds to switch off the Clean Scan function. (Exposure Time returns to its previous non-variable setting.)

Note

Do not shoot highlights in the clean scan mode as

this may cause a smear effect.

V-SHIFT

The vertical shift switch (V-SHIFT) at the front of the camera is used for displays with the same frame frequency as the camera, for example TV sets. It is an up/down type switch. Pressing the switch moves the black bar up or down so that it is no longer visible in the viewfinder. This function is only active when the camera is not genlocked and when it is not on-air.

If the frame frequencies of camera and monitor are different use the clean scan of the variable shutter function.

CRT Exposure [FT]

A third possibility can arise when shooting a monitor whose synchronisation is locked to the camera's. Stripes might be visible in the picture of the monitor. (This is more usual with 16:9 cameras.) To remove these disturbing line pairing effects between monitor and camera lines, select the CRT option with the Exposure time switch.

Exposure Time

The exposure time values of 1/200, 1/500 and 1/1000 (also 1/2000 for IT) of a second are used to capture fast moving objects so that these can be played back sharply in slow motion. The value selected depends on the speed of the moving object.

Note:

Increasing the exposure speed lowers the camera sensitivity proportionally.

On IT cameras shorter exposure times increase smear effects proportionally.

The exposure selection also includes lighting control positions which can be used when shooting with lighting that is operating at a different frequency to the camera. There are two position 50 Hz and 60 Hz. Each of these positions can be varied further in a range from -10 to +10.

To reduce flicker select the frequency closest to the frequency of the lights and then vary the lighting control in the system Install menu to obtain the best result.

EVR - Enhanced Vertical Resolution [IT]

This exposure mode on IT cameras is used to increase the vertical resolution especially for still pictures. The exposure time is set to 1/25 for PAL and 1/30 for NTSC.

5-6 Operator's Manual LDK 100 Camera Head Shooting