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IRE Setup with Matrox RT.X2

IRE is a measure of brightness for NTSC video, with black being 0 and white being 100, with shades of gray in between. In the US, the black level is normally set to 7.5 for broadcast. This means that the brightness scale runs from 7.5 to 100 rather than 0 to 100. Since Japan uses 0 IRE black setup levels, virtually all miniDV cameras will use 0 IRE for black setup when making a recording.

In Premiere Pro with RT.X2, you will find the “Setup” option in Project Settings > Playback Settings > Video Output, which by default is at 0 IRE. Knowing that the US uses 7.5 setup, the temptation is to change the setting to 7.5, but don’t do it.

Changing this to 7.5 will boost all the brightness levels in your analog video output by 7.5, which results in a washed out image where blacks become grayish and grainy. This ONLY affects the analog outputs – if rendering to DVD or printing back to DV tape via 1394, Setup has no effect. There is no harm in leaving the setting at 0 IRE, as this will provide the best results with DV and DVCAM footage.

You may be using an external video monitor to check your editing, and by changing setup to 7.5, you get a false impression of what the final DVD output would look like. You will see video with boosted brightness, then you’ll be doing color correction to try and fix something that isn’t broken!If capturing video from old VHS tapes or similar analog NTSC sources, then 7.5 setup may be appropriate in some cases. You can try and use the waveform/vectorscopes within the Premiere Pro preview monitor to see where the levels are at if you are so inclined , but if in doubt, don’t mess with it.Note that setup does not apply to any of the HD formats, so it’s a non-issue in an HDV project.

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IRE Setup with Matrox RT.X2