Emergency!!!

[Samuel H]

I always use custom WB, because it corrects both color temperature and the green-magenta thing. Very useful when you can't afford super-expensive ND filters and have to work with ones that have some color cast (in my case, the more ND filtration, the greener the image). It works great on most cameras (the only one I've found to be an exception to this was the D800; it was the first time I laid my hands on it, so it might have been my fault).

[vision_filmz]

Whole nother topic on whether (and when) you should every use the custom WB instead of just dialing in a temp. AWB is a terrible idea.

What proof do you have to say such hog wash? 90+ % of my videos I've shot use AWB & I've never had a problem. Canon dslr does AWB damn near perfect.... (Dslr shooter close to 3 years) Also any editing program you can easily adjust the white balance as well.

[gonzo_entertainment]

What proof do you have to say such hog wash? 90+ % of my videos I've shot use AWB & I've never had a problem. Canon dslr does AWB damn near perfect.... (Dslr shooter close to 3 years) Also any editing program you can easily adjust the white balance as well.

You can adjust white balance in post, but in a 4:2:0 8 bit color space you can only go so far before it's going to start to have issues.

Why would you want to let the camera control something like that (WB) that is another avenue for the artistic manipulation of the shot? what about mixed lighting situations? What about if you pan in a shot where the temp of the light changes a little because of the source? etc... etc... etc...

[Elliot Lucak]

Do you also shoot with autofocus and autoexposure?

[vision_filmz]

Do you also shoot with autofocus and autoexposure?

Why do you worry on how someone shoots? AWB is very different than exposure, very different. Have you ever used AWB on a Canon dslr? More than accurate in any and every situation, the camera just knows what white is. Also if there was ever a problem my own two eyes would let me know as I know what white is. Whenever I want to do an effect in camera I will used a certain kelvin to make it hotter/colder for anything else though AWB is more than fine.

If you or anyone thinks otherwise test it out and prove me wrong, you will be surprised how good AWB is on a Canon dslr. Regarding exposure and focus does not make sense though as I adjust accordingly what I want in focus and don't same goes for exposure.

[xxtreemfilmz]

Thanks you all for your input!!!

[xknight]

Since no one really answered your question, I'll let you know what I have found. I also regularly shoot with 2 dslrs and balance using a white card. (actually sometimes I do that and sometimes I change the kelvin temp to the temp of the lights I am using) I have seen exactly what you are talking about and here is what I found.

Since your cameras are in two different positions and your white card is reflecting light slighting differently, you can get just a slightly different reflection of some light source that your eyes don't even think it is picking up...and even though it doesn't show up weird on set, the sensor can see it. For instance one of the first times I saw this was when I was shooting in a home that had a window on the opposite side of the room. My light sources were totally hot enough to overcome the window and the window was on a shady side of the building, so it wasn't really an issue to cover it. However, when I went to white balance, one camera was great, but the other had the crazy green tint...like not even close to proper balance. I, like you, was totally confused as to why that was. I thought something got really messed up in the camera or something. Anyway, while messing around, I ended up covering that window, and voila, the camera white balanced perfectly. Even though the other camera was fine doing a white balance, something about the angle of the other camera made it pick up that daylight source and mess with the image. So in the future, if that happens, take a look around the room and see if there are any other color temperature light sources from room lights, work lights, or windows. Even if they don't seem to be spilling on the set, there may be just enough to throw off your white balance. So, at the very least just flag that light off as best as possible during the white balance (maybe even just have someone stand and hold something to block it if you don't have the proper grip gear, and that should take care of it.

Also, I have heard people say to use a white cap or a card that goes in a matte box. Don't ever do that....no idea where people come up with that. The white has to be where your subject will be shot in the same exact lighting. And don't use auto white balance. That other guy may get lucky with it, but the exact problem you had with your camera is the reason not to let the camera decide what the color temp should be. When AWB is engaged, the camera is always looking at the light to determine what the balance should be...one slight movement where you show a window in the background or a reflection of some other light source, and it is going to change to the wrong temperature. Plus, you can easily have a weird shifting from one color temp to another and back if there are two competing sources in the shot.

Good Luck!