What do you guys think of the color bleed?

[Sid Tran]

Hi guys, i just shot this this afternoon to test some settings. I've noticed color bleeding through the shirt and also when she's holding the pencil (the green bleeds through her hand). I've purposely over saturated the color to see how the footage will look without color correction. This clip hasn't been color corrected, just out o the camera.

http://www.dvfilms.net/xl2/jultest.wmvx
(Once its downloaded, just remove the 'x')


Here are the settings:

Gamma Curve: Cine
Knee Point: Middle
Black: Pressed
Color Matrix: Cine

Color Gain: +5 (1 notch to the fullest possitive)
*I think this is the reason for the bleed* ?

Color Phase: default
Vertical Detail: low
Sharpness: default
Coring: +2
Setup Level: default
Master Pedestal: -6 (all the way negative)
Noise Reduction: default

What do you guys think about the color bleed?

Thanks,
Sid

[Raymond Schlogel]

Um, yea, would kinda sorta tend to think that it just might possibly be the Color Gain.

But a little confused why you would blow out the saturation and then ask about the bleeding. It would be like putting sand in your gas tank, getting it towed to the mechanic and telling em ya think it might be cuz you put sand in the tank. Or its like ... alright, never mind ... yes, its the Color Gain.

- Ray

[Sid Tran]

wow Raymond. I'm new to this so i post a question to get an opinion. Thanks for taking the time to reply, i really appreciated.

[Rob Lohman]

It should be fairly easy to test out yourself as well on a similar shoot,
but looks like too much color gain indeed!

[Chris Hurd]

I think what Raymond is saying, is try backing off the Color Gain a bit and you might not have so much color bleeding. Thanks for sharing your settings! That's nice to see. Please do report back if you find a better combination.

[Chris Mills]

By its very nature, miniDV will exhibit colour bleeding. Even if you are careful about your exposure and choice of colours to shoot it still happens.

With miniDV only the luminance is getting fully sampled for the output information. Chromanince or chroma (hue and saturation) is sampled at a quarter of the frequency (resolution) of the luminance - hence the sample related code for these cameras (4:1:1 for NTSC and 4:2:0 for PAL). 4:1:1 equates to a full frequency luma sample and chroma sampled at one quarter frequency (full width of the image, and only every fourth vertical line so you get colour information which is stretched vertically, but not horizontally). 4:2:0 equates to a full frequency luma sample and hue/saturation sampled at one quarter frequency (every second pixel across and every other line down so with PAL your colour information is stretched both horizontally and vertically). For more info on this check out Adam Wilt's Sampling Info Page.

This is why the colour bleed exhibits those blocky looking edges (along with the manner in which the DV codec writes out data). You can minimise the impact of this by being careful with your saturation and choice of colours. I've seen some clever tricks for re-constituting compressed images by extracting the luma and compositing it over blurred chroma channels to "reconstruct" a cleaner image. I've messed about with this a little and if you are curious I would be happy to share my results sometime.

[Sid Tran]

Thank you Rob, Chris H, Chris M. I shot it during the day and when i got home and capture the footage, I noticed the bleed. I remember playing with the color gain to see if I can get a richer color without post. I don't have enough experience to just look at a footage and right of the bat know what the problem is. That's why we have forums so we can discuss and learn as we go. I'll play with the settings some more. Thanks guys, for helping out a newbie.



Sid

[Rob Lohman]

Some NLE's might help reduce this with a "chroma blur" filter,
Sony Vegas comes with one for example. If you have such a filter,
try it out, see if it helps!

[Sid Tran]

Thanks Rob, i'll give it a try.