IRE set to 0 or 7.5?

[iluvJLO]

On my Pioneer 220, when in recording mode, it's set at 7.5 by default, and during playback of a disc mode, it's also set at 7.5 default. During playback mode, when I change it to 0, it looks more natural. The blacks are black, when set at 7.5 in playback mode, it's bright and the blacks look gray. Now in recording mode, I tried setting it to 0 and it did the opposite from what playback mode does. If I set it at 0 in rec mode, it will be bright and gray out the blacks, and if I have it at 7.5 it's black and more natural looking. Why is that? Does it matter if I record at 7.5 since you can switch it to whatever in the playback mode?

[edDV]

On my Pioneer 220, when in recording mode, it's set at 7.5 by default, and during playback of a disc mode, it's also set at 7.5 default.

I'll assume you are in a NTSC country or you wouldn't have these modes.

7.5 IRE assumes a standard NTSC input (e.g. cable box, VCR, laserdisc). It also assumes your TV is properly adjusted. Easiest way to adjust the TV is with the THX test signals included with many commercial NTSC DVDs.

http://www.thx.com/mod/products/dvd/optimizerIntro.html

During playback mode, when I change it to 0, it looks more natural. The blacks are black, when set at 7.5 in playback mode, it's bright and the blacks look gray. Now in recording mode, I tried setting it to 0 and it did the opposite from what playback mode does. If I set it at 0 in rec mode, it will be bright and gray out the blacks, and if I have it at 7.5 it's black and more natural looking. Why is that? Does it matter if I record at 7.5 since you can switch it to whatever in the playback mode?

Output side - You need to adjust your TV first. After you do, it should look good if the DVD recorder (set to 7.5) or cable box, etc. is plugged directly into the TV. If not something is off.

Input side - Use 7.5 for normal NTSC inputs. Use zero for O IRE black sources like DV camcorders.

See this JVC tutorial for the basics of setting black levels for NTSC.

http://pro.jvc.com/pro/attributes/prodv/clips/blacksetup/JVC_DEMO.swf