Niewbie on the subject here,
We have 3 HVX200 cameras and have a problem of matching them up as far as whiteballance/color.
Before we do a shoot we try to match them up as best as we can just looking into the viewfinder and adjusting AWB (pointing at a same object that is white for each camera...) and color (iris , gain ..) but can never get the same quality for them all... It either looks to yellowish or off color midtones.
Do people normally just fix this through color correction in post production?

Appreciate your suggestions...
Thanks

I hope you mean custom white balance... Just aiming auto-white balance (AWB) at a white object is not going to be completely sufficient.

You should be using a white-card (technically, it can be done with a grey-card); the card should be in the expected lighting, the cameras should be maneuvered the same position relative to the card (don't move the card); zoom to fill the view with the card, then lock in the custom white balance.

Aperture adjustments should affect depth-of-field, but have no effect on white balance or color.

If the cameras are still off (shoot the white card at the start of the session -- that will give you a good target for post-process white) they may be miscalibrated internally (on something like the Canon XH A1, there are a number of cryptic customization settings that could result in such miscalibration).

Thank you for your quick reply,
I looked up "white-card" and red the "white object must be in full frame", so that might of been when we forgot to zoom to to get it in full frame.

1 ) Switch the HVX200s WHITE BAL to A or B , zoom to a solid white or gray object covering the whole frame in the general area of filming , press the AWB button for about a second until displays "AWB BCH OK" , this method right ?

2 ) But lets say we are shooting in unnatural lighting environment and our "white-card" looks bluesh or redsh with the naked eye, should we still zoom in on this even though it is off color?

Thanks !

Reverse order:

2) Regardless of what the card looks like to your eye, the camera has been told (when you set custom white balance on the object) that "this is what is to be white -- compute adjustments to make this white, and use those adjustments for the following recording". If you /want/ the camera to see it as tinted, you will have a problem. To make a custom white balance deliberately tint white to blue, you need to show it a yellow object when you set the custom white balance (removing yellow means adding blue). [This trick can be used to create fake lighting conditions -- want an orange-red sunset light on a scene? White balance on the complement color]

After all, if one is setting a custom white balance, one is telling the camera that the currentl lighting is not pure, and how to compensate.

I suggest, rather than hoping to find a "white" object in nature, hit a good photo/video store, and buy a package of Kodak grey cards. Typical package is one or two 8x10, and a 5x7. Cards are grey on one side and white on the other. *


1) Okay, terminology confession... Every camera I've purchased since 1984 (film/digital, still/video) has been a Canon. On Canon, one sets a "custom white balance", and the icon/button is marked with something like

|\/|
====

(two triangles over a bar)

From what you state above, I take it that "a" and "b" are switchable "slots" for a custom white balance, and that the AWB button is used to store a white balance into the selected slot. (On the XH A1, if my memory hasn't failed, I'd have to slide a white balance switch from Auto [AWB] to Manual, move a toggle from "preset" [presets are Daylight/Incandescent/K] to "1" or "2", lock on the white card, and then press the button with the above icon).

I'd consider that a misnamed button <G> Use "auto white balance" to /turn off/ auto white balance and store a custom white balance???



* The reason a grey can be used for white balance is that the camera will assume it is grey due to low lighting, and "adjust" the effective exposure to make it white (only for setting the balance; for determining the exposure, it assumes 18% grey -- if you tried to set the exposure using the white side, it would underexpose to make white look grey).

The auto exposure and auto white balance modes both work on the assumption that, if you averaged everything in the scene into one color, that color would be 18% grey.

I'm just guessing here but if I wanted to add a fake tint to a video (which seems to be a very common thing to do in movies recently) and I had 2 different cameras and wanted to match their output I would just attempt to set the white balance manually before shooting and add any tints I wanted later in post. It is asking for a lot of extra work IMO to try and match a special tint situation with two different cameras in the field. I would think it would be very hard to do since the different cameras are going to make adjustments differently. My two cameras certainly do.

I always do a manual white balance setup before shooting which gives me video that is reasonably close from my 2 cameras. I still need to make corrections in post though because the 2 cameras just have different characteristics in how they react to different tints and shades of lighting. It may take more time to process my video after I shoot but I generally have a good idea how to make the output similar now and it's just a matter of letting my computer do my rendering overnight. If I needed to add a special tint I would certainly try to do it in post rather than try to get 2 different character cameras to react to a change in the color I use as a base for my white balancing. I can see where that would work great with matching cameras but with two different cameras it's just asking for problems IMO.