White balance question
 

I understand that you can manually dial in your WB by setting your WB switch to PRST and going into your PP and adjusting it there. I've noticed that there's a different look between a 3200k that you might get with a white balance card hitting the button, and 3200k that's manually adjusted. Is it because there's some adjustements made (gamma,knee) in the picture profile that make it look different? I thought it was set to default that you could work from there. Please tell me if there's an easier way, this is how I'm obtaining it doing weddings and such... I just press the white balance button not necessarily focusing it on a white object, and the look seems pretty close. I take that color temp then go into the PP and fine tune it to someones face or whatever looking at them then my LCD. I'm sure this is ridiculous. I never use AWT and have not been that impressed with my WB card being accurate. Maybe it's just me. Any suggestions would be appreciated.

There are a lot of factors. Are your lights really 3200K? Have they been on long enough? Dimming changes color temperature as does age of the bulb. Are you receiving the direct source of the light? I'm often surprised by the coloration of nearby mirrors that are invariably made with a glass with greenish tint. Is your white card really spectrally neutral?

Adjusting by sight isn't very accurate as your LCD is usually not calibrated, and ambient light and your material will throw you off.

When you perform an auto white balance using the WHT BAL button, a green/ magenta shift is also performed to balance to your white light. As fluorescent lighting is becoming more prevalent this could be just what you need. By performing an auto white balance on a non-neutral source, whereas it may look O.K in the viewfinder, chances are you are introducing unwanted colour shifts. This is also true for cards/ objects that may look white to the naked eye but are in actual sense non-neutral.
A manual white balance on the other hand only shifts the orange/ blue hues. Perfect for natural and tungsten lighting.
The EX cameras were made for 3200K studio lighting, which I doubt you would shoot under when it comes to weddings. A better bet would be 2600-2800K for manual, provided the lighting isn't fluorescent.
If I'm stuck, balancing off of the light-source itself is pretty accurate. Zoom in on the light, engage ND2 and stop down so that you are not clipping in any channel (this means you should be under 100IRE/ 700mv) and hit the WHT BAL button once and another time after that to be sure. Works for me just fine.

Thanks guys. That clears up a bunch of questions. I really appreciate it.

Omar is right about the green magenta thing. You can also set your white balance in the menu to always be a little warm by adjusting to white offset ( I think that's what it is)

The most reliable thing is to carry a piece of white paper with you at all times - whip it out when you need it. If you can't do that - like Omar said you can use a light source or any white fabric. At a wedding the tablecloths are often pretty good.
However not all white's are white. Sometimes white balancing on a fabric will give you surprising off hues doublecheck in the viewfinder as well.

At a wedding you are usually in mixed light which is a bear and may make balancing off a source misleading so you want to find a white or place your white apper in the place taht gives you the best mix. Try a couple fo angles till you get the color right.
White balancing without pointing at something white is nuts, but the white doesn't need to completely fill the frame

Flourescents are usually pretty good to point at it if its the main source in a room.

It isn't necessary to WB from a white card, cloth etc. But it is important that it be a neutral colour, meaning gray. A Kodak 18% gray card is ideal. If you use white, stop well down (a couple of stops) to get an accurate setting.

Be careful white balancing off paper or card - some have optical brighteners which fluoresce under UV to make them look brighter and 'whiter than white'. In sunlight, these add a blue tint to the reflected light and result in the colour temp being too high.

I normally white balance off a Lastolite diffuser.

Nick

Don't forget that exposure is important when white balancing. If you WB with auto iris turned on, you'll get different results than if you have auto iris turned off (and you have a poor exposure).

Personally I like using Preset especially when I'm working with a mixture of light sources.

If the light is mostly tungsten (standard light bulbs, etc...) then I choose 32k. This way, everything looks correct, but when you have light coming in from a window, it looks blue, which is normally okay.

If there's a LOT of light coming in from the windows and not much artificial light, then I might turn off the lights and use 56k.

If I'm in an office setting with bright fluorescent lights, then I choose 41k.

When it gets tricky is when there's a lot of light coming in from the windows but I need to shoot some talent in front of them (I only have tungsten lights). I "should" either gel the window's to shift them to tungsten (32k) or gel my lights to shift them to daylight (56k) but I personally don't have enough gel material to do this. I normally just try and stay away from windows for this reason.

I've been considering purchasing a set of the new Lite Panels Bi-Color lights that adjust from 32k to 56k. I think these would be ideal to work with in mixed light situations. Unfortunately they are pretty expensive. I'm going to check them out at NAB in April. See if they are worth it.

My worst case situation is shooting a spokesperson inside a car dealership showroom. Most showrooms have a lot of windows (sometimes the entire room is made of glass exterior walls), but I need still need additional light to make the spokesperson look good. This is where daylight balanced lights would be perfect. But I'm not sure if the Lite Panels would be strong enough in this situation.

The point is, if you're shooting indoors without and talent (spokesperson) you can normally get away with using Preset. I think it looks better as the color of objects underneath the light sources will look correct, but the small amount of light coming in from windows will look blue, and in my opinion, that will look real nice.

So when you're shooting under fluorescent lights, you wouldn't try to white balance, you would just go into your PP and dial in 41k? I've learned a bunch from what has been said, but not still a bit uneasy about if I'm doing a ceremony (indoor) and whether I should just figure my might source and perhaps just use a preset of 3200 if tungsten or use a white source and WB off of that. (I'm guessing that I can do both and I should jude the look accordingly) I know I'm backtracking here from what was said. I'm just curious to how often people maunaully adjust it through the menu compared to letting the camera determine it. Sounds like if I'm shooting under fluorescent, then I should use the WB button upon a white source since it shifts green/magenta also. If I'm dealing with Tungsten/outdoor then I'm ok with using a preset or going through my pp and adjusting it there.

"So when you're shooting under fluorescent lights, you wouldn't try to white balance, you would just go into your PP and dial in 41k? "

Don't know where you got that from above. Just the opposite - Under flourescents you need to white balance otherwise you will often have green - magenta problems.
I like white paper exactly because it is slightly blue ands warms up my white balance. But the bottom line is you need to experiment and find your own methods.

I think there are a lot of different techniques to getting a "good" white balance. Some people are ultra-critical and others just want it to be close (fix it in post). I use 4100 for fluorescents. I think that normally looks great. White balancing wouldn't be a bad idea either.

The really tricky lights to shoot under are the mercury vapor lights they use inside big gymnasiums. The ones that take forever to turn on.

If your not happy with how it looks in your LCD, then I would white balance and see if it looks better. I know you can't totally trust the LCD, but it will get you very close (if you have it set up to color bars).

I always carry a 2" by 2" book of gels that include CTO, CTB and green and magenta in fractional sizes. Rosco used to make one for free called a jungle book but discontinued it so now you need a full swatch book. But i wouldn't be caught dead without it.

Sweet... If all of you lived in Portland OR, I would take you out for coffee! :P Thanks for your insight.

That's a really nice town.

I'll take a rain check.

I was just in Portland for the Cascade Video Show. Were you there?