Black and White Points

Author: dark_jedi
Date: 6-Feb-2006, 8:53 PM

Author: dark_jedi
Time: 6-Feb-2006 8:53 PM
Post link

Hi i just got CSamp from the X0project website, and read on the B&W point settings,and i am following the directions as given,but when i put the cursor on the black bars,i get no RGB numbers,but the box is black, also when you do get numbers should RGB be the same number?i tried a white area and all three were differnet numbers,am i doing something completely wrong here?
thanks in advance
DJ

Author: Sluggo
Time: 6-Feb-2006 11:37 PM
Post link

Isn't Black 0, 0, 0; and white 225, 225, 225? I suppose black technically wouldn't have any numbers.

Author: Moth3r
Time: 7-Feb-2006 8:34 AM
Post link

I've never used CSamp, but you can achieve the same thing by copying the source frame to clipboard in VDub, paste into MSPaint, select your point using the colour dropper, and go to Colors -> Edit Colors... Define Custom Colors.

Guidelines for post content and general behaviour: read announcement here

Max. allowable image sizes in signatures: reminder here

Author: Knightmessenger
Time: 8-Feb-2006 5:25 PM
Post link

Could someone explain to me in very basic terms what the purpose of setting black points is? Does it have advantages over just adjusting the brightness and contrast. The greedo pictures from the X0 article didn't really look that different, just that one had more contrast. Is there a screen capture frame which can show a more noticable improvement available?

Take back the trilogy. Execute Order '77

http://www.youtube.com/user/Knightmessenger

Author: Moth3r
Time: 9-Feb-2006 2:52 AM
Post link

In very basic terms:
setting the black level is adjusting the brightness
setting the white level is adjusting the contrast

These images may help explain the advantages of setting black and white levels correctly:

http://img211.imageshack.us/img211/9651/calibrate24tv.jpg

http://img207.imageshack.us/img207/6048/calibrate17hh.jpg

Guidelines for post content and general behaviour: read announcement here

Max. allowable image sizes in signatures: reminder here

Author: Knightmessenger
Time: 9-Feb-2006 8:45 PM
Post link

Ok, that helps but then what's the advantage of going through the tedious process of manually adjusting black and white points if it's just the same as adjusting brightness and contrast. Does this way allow you to only adjust part of a frame and leave the rest unaffected? For example would this help the starfield become black without making Tatooine turn to a dark brown mud color?

Take back the trilogy. Execute Order '77

http://www.youtube.com/user/Knightmessenger

Author: Moth3r
Time: 10-Feb-2006 3:35 AM
Post link

I'm not sure I understand the question.

You set black level by adjusting the brightness control, and the white level by adjusting the contrast.

On my analogue capture card, I can adjust the brightness and contast in the capture driver settings. With the levels set correctly, I can capture the full "gamut" (range of levels) of video from black to white with no clipping or crushing.

If for some reason you have a video capture with a smaller gamut, you can remap by adjusting the levels in post-processing (as described in the guide on the X0 site). After remapping, you then have the full gamut for encoding to DVD.

Guidelines for post content and general behaviour: read announcement here

Max. allowable image sizes in signatures: reminder here