Getting Capture Levels Right (Proc Amp Settings)

[ehbowen]

Sanlyn has consistently criticized my captures for illegal video levels...with reason, I must admit. I'm planning now to (re)capture two rare tapes from 33 years ago which may well be unique; one was a broadcast by Australia's Channel 7 of the 75th anniversary celebration for the Royal Australian Navy in 1986 which features the battleship USS Missouri; it was converted to NTSC and professionally duplicated by Channel 7 for sale to crew members as a souvenir. The other is a compilation video produced by the ship's Public Affairs Office using the Beta-format TV studio on board and featuring several slideshows of still photos taken by the crew and set to music.

This time, I'd like to get the capture proc amp settings right to make further cleanup and editing easier. Both tapes are in very good condition, SP mode, professionally duplicated, but straight VHS. Looking at the histograms with default settings I see a significant amount of red at both ends of the display. The colors on the ship's PAO video, especially, are a bit washed out; that's not tape deterioration but, shall we say, equipment limitations and operator error during the production process. I'm able to capture and post samples if you can let me know what kinds of clips will be most helpful.

I will be using both my ATI AIW 8500DV and my ATI AIW X1800 workflows with a TBC-4000 for time base correction. I have a couple of suitable VCRs; one Panasonic AG-1980, two Mitsubishi HS-HD2000Us, and a pair of high-end JVC S-VHS machines. I'll probably be using the JVCs for this job as both tapes are SP; I try to save the Panasonic for the toughest tapes and the Mitsubishis are my normal go-to machines for non-problematic EP tapes.

[ELinder]

If have Virtualdub set up so that you're already seeing the histogram and the red clipping at both ends, you're most of the way there. Play the brightness and contrast settings in Virtualdub and you'll see the histogram change while the tape plays until the red is just gone. You'll want to check a few different places on the tape. When you have it, turn off the histogram and then just capture with those settings.

Erich

[sanlyn]

Surprised you haven't found it yet, but take a look at the thread Capturing with VirtualDub [Settings Guide]. You should temporarily crop off side borders and head-switching noise to stop those areas from affecting your histogram measurements. Use the brightness control for black levels, contrast for brights. Post #3 and post #4 have illustrations and details for the proc amp dialog, the histogram, and other setting details.

Don't forget to completely disable cropping after you make your adjustments. I forgot once, and had to capture the whole damn 90 minutes over again.