black balance?

[Tony_Reyes]

I have a decent understanding of white balance but what is black balance?

Can anyone help me out here with a reasonably detailed description?

Thanks in advance.

 

[mikkowilson]

Just as the relative levels of the 3 colors from the sensor need to be "balanced" (calibrated to each other) at their brightest values for and accurate white point; they also need to be balanced relative to each other at minimum light values, their black point.


Basically white-balancing moves the dot respective to white to the center of a vectorscope, and black balancing moves that black dot to the center too.

- Mikko

 

[Barry_Green]

The camera shuts the iris and looks at the chipset. With no light coming in you'd expect that the chips would be delivering a completely black image. If it isn't, the camera figures out what portions aren't perfectly black and adjusts them so that they will be black.

 

[mikkowilson]

...So that's what it is, and how it works.


- Mikko

 

[Tony_Reyes]

i haven't been asked to do a black balance yet. so if the iris closes, i don't need to be pointing the lens and anything black? like what you're doing when you white balance?

 

[Drew Ott]

...So that's what it is, and how it works.


- Mikko

It's OK...

...he's Barry Green.

 

[Barry_Green]

so if the iris closes, i don't need to be pointing the lens and anything black? like what you're doing when you white balance?

Correct -- the iris closes completely, so it doesn't matter what you point it at. And you should do a black balance every once in a while anyway.