black balance at DVinfo.net

Andzei Matsukevits · January 14th, 2007, 07:07 AM

do you guys adjust black balance of HVX?
I always do white balance, but never done black balance...

Jason Boyce · January 14th, 2007, 08:04 PM

Black balance is just setting the voltage through the CCD to zero and balancing that image to pure black. The camera does it every time you white balance.

Greg Boston · January 14th, 2007, 08:20 PM

Quote:

Originally Posted by Jason Boyce

The camera does it every time you white balance.

If the camera has a separate black balance function, then I have to disagree there, Jason.

I can't attest to the HVX200 because I don't own one. However, the Sony F350 not only has a separate black balance, it has two modes... a quick BB and a more thorough BB which wipes out the previously stored values in the matrix and starts over from scratch.

In contrast with that, my former Canon XL cameras had no such user function and may have performed the function automatically along with WB as you suggested.

regards,

-gb-

Mike Schrengohst · January 14th, 2007, 09:15 PM

To set the HVX200 black balance you just hold the white balance button longer and then the bb is adjusted.

Greg Boston · January 14th, 2007, 09:19 PM

Quote:

Originally Posted by Mike Schrengohst

To set the HVX200 black balance you just hold the white balance button longer and then the bb is adjusted.

Thanks for the clarification, Mike. So as I understand you, it's not automatic, correct?

-gb-

Robert Lane · January 14th, 2007, 10:04 PM

Page 41 of the manual clearly shows the how and why to use ABB adjustment.

Black balance is not automatically done when the white balance is performed, it is a separate operation but unlike AWB it doesn't require using a card in front of the camera, the camera takes care of ABB internally, and as described in the manual it should be done more often than you'd think. The manual suggests doing an ABB:

- When using the cam for the first time.
- When using slow shutter speeds
- When temperature changes are drastic
- When switching between "interlaced" and "progressive" modes
- After a long period of not using the camera (that period is undefined by the manual).

A good rule of thumb is that if you have to do an AWB you could also do a Black balance. It's just a few extra seconds of time and has no detrimental effects on the camera.

Andzei Matsukevits · January 15th, 2007, 07:53 AM

sorry, if i didnt get it. But can i adjust BB if the cap on? Or i dont need anything in front of camera?

Brian Drysdale · January 15th, 2007, 09:16 AM

Quote:

Originally Posted by Andzei Matsukevits

sorry, if i didnt get it. But can i adjust BB if the cap on? Or i dont need anything in front of camera?

I expect the HVX200 works like other video cameras when doing an ABB, the lens iris automatically closes completely.

It's generally good practise to do a black balance at the start of the shooting day. I'd also do it if you change your gain settings in the menu.

Robert Lane · January 15th, 2007, 03:16 PM

Quote:

Originally Posted by Andzei Matsukevits

sorry, if i didnt get it. But can i adjust BB if the cap on? Or i dont need anything in front of camera?

That's right, it doesn't matter if the cap is on or not when doing an ABB adjustment. And Brian's suggestion of doing a ABB at the beginning of a shoot is a good idea. The few seconds it takes to do it can do wonders in helping keep the output as good looking as possible.

January 14th, 2007, 07:07 AM	#1
Andzei Matsukevits Major Player Join Date: May 2005 Location: Tallinn, Estonia Posts: 300	black balance do you guys adjust black balance of HVX? I always do white balance, but never done black balance...

January 14th, 2007, 09:15 PM	#4
Mike Schrengohst Major Player Join Date: Apr 2006 Location: Dallas, TX Posts: 355	To set the HVX200 black balance you just hold the white balance button longer and then the bb is adjusted. __________________ Mike Schrengohst dvd.pro@verizon.net

January 14th, 2007, 08:04 PM	#2
Jason Boyce Regular Crew Join Date: Apr 2006 Location: San Francisco, CA Posts: 77	Black balance is just setting the voltage through the CCD to zero and balancing that image to pure black. The camera does it every time you white balance.

January 14th, 2007, 10:04 PM	#6
Robert Lane Go Go Godzilla Join Date: Nov 2004 Location: Scottsdale, AZ USA Posts: 2,823 Images: 15	Page 41 of the manual clearly shows the how and why to use ABB adjustment. Black balance is not automatically done when the white balance is performed, it is a separate operation but unlike AWB it doesn't require using a card in front of the camera, the camera takes care of ABB internally, and as described in the manual it should be done more often than you'd think. The manual suggests doing an ABB: - When using the cam for the first time. - When using slow shutter speeds - When temperature changes are drastic - When switching between "interlaced" and "progressive" modes - After a long period of not using the camera (that period is undefined by the manual). A good rule of thumb is that if you have to do an AWB you could also do a Black balance. It's just a few extra seconds of time and has no detrimental effects on the camera.

January 15th, 2007, 07:53 AM	#7
Andzei Matsukevits Major Player Join Date: May 2005 Location: Tallinn, Estonia Posts: 300	sorry, if i didnt get it. But can i adjust BB if the cap on? Or i dont need anything in front of camera?