Black Balance

F

funkytwig

Active member
Been reading up on this and the manual makes it sound like a real knitemare. It says you should do it if you change gain or go to PB mode and back. The full list includes changing shutter speed and great change in ambient temperature.

So do is it done after White balance.

also how much difference will it make after the changes listed above. I do a lot of run and gun and having to do it whn i go from inside to outside sound unconvincing. I suppose one I have presents for both this will then have them (as long as I dont change shutter speed).

I also hear of the trick to just do black balance by putting on lens cap and trying to do a white balance, that sounds great. I can however work out why this works, does the camera not have to be able to see something with black in it?

Any advice of this would be great.

Ben
 
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Many cameras will say "White balance fail" if you try it with the lens cap on! Never heard this one at all. I'm surprised it would ever work as white balance is adjusting the colour balance to give white, while black balance is trying to find a real black, which includes tweaking the gain at the bottom end.
 
Black balance and white balance aren't the same thing at all; you absolutely won't be doing a black balance even if you could do a white balance with the lens cap on. Where did you hear this?

Black balance is really simple and easy; it only takes a second and you can do it anywhere, at any time, with nothing special to point at. The camera does all the work and it doesn't matter what the camera is pointed toward, because the iris is totally closed the whole time. You can do it while walking between shots without even looking at the viewfinder.
 
David Jimerson said:
Black balance and white balance aren't the same thing at all; you absolutely won't be doing a black balance even if you could do a white balance with the lens cap on. Where did you hear this?

Black balance is really simple and easy; it only takes a second and you can do it anywhere, at any time, with nothing special to point at. The camera does all the work and it doesn't matter what the camera is pointed toward, because the iris is totally closed the whole time. You can do it while walking between shots without even looking at the viewfinder.
Click to expand...

Thanks, so the lense cap trick works. The camera is suposed to say it cant do a white balance and do a Black Balance instead. So I guess it uses the white balance seting to feed into the calibration so White Balance should be done first?
 
David Jimerson said:
Black balance and white balance aren't the same thing at all; you absolutely won't be doing a black balance even if you could do a white balance with the lens cap on. Where did you hear this?

Black balance is really simple and easy; it only takes a second and you can do it anywhere, at any time, with nothing special to point at. The camera does all the work and it doesn't matter what the camera is pointed toward, because the iris is totally closed the whole time. You can do it while walking between shots without even looking at the viewfinder.
Click to expand...

Indeed, what I was saying is if you have lense cap on and try to do a white balance it fails and does a Black balance instead.
 
The lens cap doesn't have to be on. The camera shuts the iris and doesn't allow any light in when it performs the black balance.

If you hold the button, it'll do a black balance no matter what the white balance does, and it'll work perfectly every time. You never need to have the lens cap on.
 
Unless, of course, you're using a manual lens - still, with the AF, compared to any camera I've used, black balance is a cinch... check out the instructions for the Canon C cameras if you don't believe me.
 
Mac is saying the AF100 is easier than the C100. Here's the C100's black balance procedure:

Adjusting the Black BalanceYou can have the camcorder adjust the black balance automatically when ambient temperature changes
considerably or if there is a noticeable change in a true black video signal.
Operating modes:
1 Open the [ABB] screen.
[~ Camera Setup] > [ABB]
2 Attach the body cap to the lens mount.
• If a lens was attached, remove the lens and replace the body cap.
3 Select [OK] and then press the joystick.
• The automatic black balance procedure will start.
4 When the confirmation message appears, press the joystick.
• If the body cap is not correctly attached, [Error] will appear on the screen. Press the joystick and repeat the
procedure from the beginning.
Click to expand...



...vs. the AF100...

Black balance can be adjusted by holding the AWB button even when the ATW function is in use
Click to expand...
 
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Hmm, didn't know that - it always seemed to close the iris on the lens when I did it - That really makes it easier...
 
Damn... have always used the lens cap for black balancing on my AF100s and AC160a. Or have set the WB switch to PRST to avoid messing up any current white balance settings.

Have read many forum discussions about black balancing (including comments from Barry and Jan) in addition to manuals and books. And this is the first time I've ever heard about it being this simple. Great to know.

Do you know if this applies to the new HC-X1000 as well?
 
The HC-X1000 does shut its iris entirely when doing a black balance. All the Panasonics do. On the AF100 they added a separate physical iris to accomplish that; with the other cameras it uses the lens' built-in iris.
 
tflak said:
...And this is the first time I've ever heard about it being this simple. Great to know.
Click to expand...

Really? I've always thought that ABB was one of the easiest to use features of the Panasonic cameras I've used (DVX100, HPX500, HVX200, AF100). All single press/flip button/switch operations. I had no idea that there was any confusion about it. Looking at the C100 BB procedure, Panasonic's implementation seems like a dream by comparison.

Shawn
 
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