Contrast?

[Craig Bellaire]

Just wondered where if any is a contrast adjustment... Or when we turn Black to 7.5% is that considered a contrast adjustment... thanks

[Boyd Ostroff]

Contrast is something you need to adjust in post. Just be certain that you properly expose your footage in the first place (use the zebra patterns). The 7.5 IRE setup is a bad idea, it will raise the black level of everything such that things which should be black are now gray. Leave that set to 0 for best results.

[Ronald Lee]

woah, my friend, whom I assume knows what he's doing, set my black to 7.5. Is 0 the best? Are we agreed on this?

My outputs are: DVD, TV broadcast, possible film tranfser

[Boyd Ostroff]

Ronald, as I understand it, setup is something which should be added during playback, not recording. By setting this to 7.5 IRE you will never get a true black from the camera, so you won't get the full dynamic range that DV offers (which is very limited to start with). 0 IRE is the standard for digital video, not 7.5.

The Sony cameras have a different problem with setup however. If you plug a monitor into the s-video output everything will look too dark because the MONITOR wants 7.5 IRE and the camera is providing 0 IRE. The correct fix for this would have been for Sony to give us the option to raise the IRE level to 7.5 during PLAYBACK, and not to raise it during recording. Perhaps your friend thought that setting the black level to 7.5 was doing this instead?

OTOH, if you you like the way everything looks with the camera set for 7.5, then by all means keep right on using it...

[Ronald Lee]

Originally Posted by Boyd Ostroff

Ronald, as I understand it, setup is something which should be added during playback, not recording.

Thanks.

as an example, how is this done in, say, Premiere? I've never heard of anyone saying they have to add or take away blacks. Perhaps they can't see the difference?

[Boyd Ostroff]

Ronald, we already have a long thread devoted to this topic here with lots of good information, including a link to Graeme's article:

http://www.dvinfo.net/conf/showthread.php?t=45073

However - as I understand it - you should not mess with setup at all in your digital source material. It's an option you should be able to set on your tape deck which would only affect the analog signal it sends to your NTSC monitor.

[Sean McHenry]

Ideally, the camera should only record at 0 IRE and have 7.5 or 0 as an option on the analog output of the camera so it will display correctly on a regular video monitor. Actually, the default for output in analog should really be locked in at 7.5 as I can think of no real reason to have a o IRE signal going to an analog monitor.

See the thread and search for others on "Black Level" or "Setup Levels". Be warned that there is a wide range of confusion on this issue.

You might also want to search out threads dealing with balck levels for DVD. DVD players actually add 7.5 on their output. If you have 7.5 on your source material, make a DVD of that then your DVD will actually end up with setup at 15, double where it should be.

Read the other threads for ideas then use your best judgement as to how you want your workflow.

Sean McHenry

[Ronald Lee]

Another question.

If the DVD set top player will add 7.5 IRE to the image and thus lighten the blacks..... will the DVD software playing movies on the DVD-ROM on the computer do the same thing as well?

I'm shooting all my video on 0 IRE now because of this thread.

thanx

[Boyd Ostroff]

That's a good question, probably difficult to answer. Computer monitors don't have the same gamma as video monitors/TV's, so things usually appear too dark unless your software is somehow compensating for this. You could get some idea of how accurate the black level is by putting the NTSC color bars on your DVD. The 11.5 IRE PLUGE bar should be the only one visible: http://www.videouniversity.com/tvbars2.htm

[Sean McHenry]

Excellent point Boyd brings up. I have to remember to start doing this but, everyone should start embeding a 30 sec piece of bars and hide the button on the DVD interface so it isn't easily found. You can then go into the DVD playback menu, and since you know where the "easter egg" is, you can activate the bars (and tone?) and do a quick system setup.

That way, next time the boss asks, why is that presentation so dark/light on the conference room monitor, you can adjust it and prove someone was playing with the brightness controls again - like Marv. Not that this has ever happened to me mind you (Marv, you listening?)

It wouldn't huet too much to add 30 sec of video/audio to a DVD menu and would give you a good way to test levels on video and PC monitors.

Good idea Boyd.

Sean