FORUMS: list search recent posts

White balancing

COW Forums : Panasonic Cameras

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Rick Pearl
White balancing
on Dec 6, 2008 at 5:39:23 pm

Using the HVX-200, I zoom in as much as I can on a white balance target that someone is holding at around 12-ft from the camera. I am unable to get the white target into the shot completely, so part of the wall and the person holding it is in the shot also. I am guessing that this is affecting the calibration of the camera's white balance. What do you do in this situation?

Thanks!


Return to posts index

Jeremy Garchow
Re: White balancing
on Dec 6, 2008 at 7:25:44 pm

It doesn't have to completlely fill the frame. Are you getting a bad white balance?


Return to posts index

Rick Pearl
Re: White balancing
on Dec 6, 2008 at 8:10:38 pm

I think it is slightly off...I just figured if the camera is not able to get the complete white of the card and was also getting something else, it would confuse it.



Return to posts index


Noah Kadner
Re: White balancing
on Dec 6, 2008 at 7:43:16 pm

Move the camera or person closer.... It's actually best if the frame is completely filled by the white balancing image. I use (and sell) white cards because they are very consistent and easy to carry with you.

http://www.callboxlive.com/store/warmcards-complete-p-42.html

Noah

Check out My FCP Blog and my new RED Blog. Unlock the secrets of the DVX100, HVX200 and Apple Color.
Now featuring the Sony EX1 Guidebook, DVD Studio Pro and Sound for Film and TV.
http://www.callboxlive.com


Return to posts index

Rick Pearl
Re: White balancing
on Dec 6, 2008 at 8:12:27 pm

Thanks for the link I will check them out.

Are you suggesting that it does not really matter if I have the white card being shot at the place where the subject will be in the video and instead I could just move the person so close that it will completely fill the frame with the card?



Return to posts index

Jeremy Garchow
Re: White balancing
on Dec 6, 2008 at 8:24:01 pm

I would move the camera in your case so that you pick up the key light. The Warm cards that Noah linked to are awesome. You can also white balance through gels if you aren't getting what you want. Also shooting a Macbeth grey scale helps (black, grey and white).

Jeremy


Return to posts index


Matthew Romanis
Re: White balancing
on Dec 6, 2008 at 10:01:17 pm

Rick, you will find yourself in many situations where there is even light and saturation all over the location you are shooting in, and other times where the light on your subject is unique, or at least different.
You will need to be able to tell the difference so you know if you can perform an overall balance, or be more specific to a particular position and angle. If it is the latter, then walk the camera over to the subject location and balance there, then return to your shoot position.
In no situation should you balance on the long end of the lens, wide or mid lens is OK, but the natural "port holing" that occurs in all zoom lens's on the long end narrows the colour frequency of light entering the lens, the result is that the light being measured by the CCD/CMOS sensor is slightly different. You can measure this on an RGB parade.
White balance in some situations is not as simple as just pointing the camera at white and balancing, you have to pay attention to the angle of the white card, reflected light on the card, colour differences across the set, and the position of the card to the camera.
It is very important to use the same source of "white" all the time, that's why using a source card such as the ones suggested by Noah is such a good idea.
So often I see cameramen looking for white in the location they shoot in, it may be a piece of paper, or the side of a fridge or a white car. All these "whites" are different, so each time the camera balance's it's doing so with a different ratio of red and blue to green (green is always the reference colour and blue and red are individually adjusted to make a blend of all three signals to produce a standard white).
Many other factors of camera set up have a bearing on this, but let's keep it simple.
Do a simple test yourself, from your house get a white piece of paper, a white ice cream container lid, and a white T shirt. Place them together under the same light source and observe the difference between them, which one is correct?
The answer is none of them, but to be consistent you have to pick one of them.
You'll notice that one of them has a slightly green tinge to it, this means that the camera will balance with a bit more red and blue blending to even out the difference. The resulting image will be slightly rosey or even a bit mauve in tonal colour.
If the white source is blue in tone, then the camera will add red and remove blue resulting in what people often call a "warm" tone.
If the white source is red in tone, then blue will be added and red removed resulting in colours with a blue tone.
True white, the kind of white with all the tonal qualities that the camera was originally set up with in the factory, can be bought but it is quite expensive, and changes consistency when exposed to ultra violet light.
So the best idea is to buy a couple of source cards, use one regularly and keep an eye on it's tonal quality by comparing it to a "safe" one that you keep in a light and dirt resistant pocket.







Return to posts index

Rick Pearl
Re: White balancing
on Dec 7, 2008 at 12:57:01 am

Thanks everyone!



Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2019 CreativeCOW.net All Rights Reserved
[TOP]