EX1 and the (Auto) White Balance

[Leonard Levy]

This thread is interesting if it discloses a bug but its hard for me to understand because to me it seems like people seem to be consistently misusing terms to describe:

1-manual using the preset white balance - i.e. changing the color temp and/or the green mag shift in the PP menus

2 -manual using the AWB button- which of course uses the word "auto" which is confusing.

3- full auto using ATW.

Please straighten this out so i know what your talking about.

[Piotr Wozniacki]

Originally Posted by Leonard Levy

Please straighten this out so i know what your talking about.

You're right Lenny - let's talk strictly about how the ATW _SYSTEM_ is functioning, NOT the WB push-button (it's a separate thing).

[Bob Grant]

Perhaps this discussion would have some merit if someone can explain how an ATW system can work.
Please include in your explaination how a camera could tell the difference between a while card illuminated with orange light and an orange card illuminated with white light.

[Piotr Wozniacki]

Bob,

I really don't have this profound knowledge, but I know a system like this can really work well - in fact, on my old V1E I used it most of the time with great success.

[Leonard Levy]

Frankly I'm not sure what system you guys are actually talking about.
is it actually the ATW that you've been complaining about?

[Piotr Wozniacki]

Originally Posted by Leonard Levy

Frankly I'm not sure what system you guys are actually talking about.
is it actually the ATW that you've been complaining about?

Yes, Leonard - it's not responsive enough, and sometimes (especially when it should decrease the colour temperature, like when going inside from the sunlight) it doesn't work at all.

Or does, after several minutes (sic!). It's much more predictable the other way around.

[Serena Steuart]

Originally Posted by Bob Grant

Perhaps this discussion would have some merit if someone can explain how an ATW system can work.
Please include in your explaination how a camera could tell the difference between a while card illuminated with orange light and an orange card illuminated with white light.

If you're happy with rough WB then the AWB does a good job. But not much use if you actually want a good WB, but useful in those situations where you can't do anything else. If your shot transitions from outdoors to indoor lighting, better to set up before hand and flip the preset WB at the appropriate time. I assume that the camera looks at the relative magnitude of the RGB peaks, comparing that to stored data for "standard" scene. Maybe my expectations of AWB aren't high; I've been surprised how well the EX does the job. Naturally will fail if the scene isn't "typical" (orange card, white light).

[Sean Seah]

The main prob i faced was the lighting changes in a ballroom. When switching on from start, the image was really orangy. If I was using my old FX1, the image would be ok after 2secs. It seemed that the EX1 on ATW mode didnt respond to the lighting, event after a full min.

There was also a situation when the bridal couple walked into the hall. The lights were dimmed totally and turned on with a spotlight on the couple. The cam went haywire then.. totally orange again. Then half way thru the stroll, the ambient hall light was turned on. Again there was no response form the ATW.

I'm thinking how to handle this situation. If I set the WB manually , would the different brightness cuz a problem? Becuz at weddings here, the lighting keeps changin from time to time. We do not have dancing here, only 2 march in where the lighting will change.

[Bob Grant]

The changes in exposure shouldn't interact with the white balance settings.

What I find most frustrating with the EX1 is that out of the box the only preset is for tungsten. One of my associates bought me his first EX1 footage to do some work on, great shots except all outdoors with tungsten WB.

By comparison his 709 camera has a filter wheel with 3200K, 5400K, ND1 and ND2 positions. I wouldn't say those two filters are perfect for every situation but more than close enough to easily grade.

I think when faced with one of those nightmare situations of dimmed tungsten lights, full tungsten, halogen and daylight best to just stick to two presets, one for daylight and one for tungsten. Dimmed tungsten has so little blue in it better to just leave it a bit orange. Correcting it in camera or post is going to need so much gain in the blue channel the noise could be really bad. On the other hand the eye will accept the orange/warm tint quite happily.

My approach with scenes with mixed light sources is if there's any hint of daylight in the scene then balance for daylight. Orange casts look warm, blue casts look repulsive to the eye.

[Sean Seah]

Thks for the tips. I will try it out.

[Serena Steuart]

Originally Posted by Sean Seah

There was also a situation when the bridal couple walked into the hall. The lights were dimmed totally and turned on with a spotlight on the couple. The cam went haywire then.. totally orange again. Then half way thru the stroll, the ambient hall light was turned on. Again there was no response form the ATW.

Employing auto on anything is to be avoided if possible, more so in matters of WB. One thing you don't want is the camera chasing some nominal WB, because time varying errors are very tedious to correct in post. The bridal scene you mention is just such a problem -- not in any way a typical scene and the camera won't "know" what you want. This isn't a fault of the camera -- as a professional you are expected to carry out a WB, or in default make sure it is economical to correct in post.
Nevertheless, as I mentioned above, my EX1 responds as expected in AWB so you may need to check your settings.

[Dustin Gray]

I always use warm cards to do a manual WB each time I move into a different light setting, dont understand why you would even use AWB.

Can someone please explain the benefits over setting manually apart from lazyness?

[Dave Morrison]

I've always been a little puzzled by using a "white" card that isn't white. I understand the use of a bluish card to skew the results toward a warm white balance, but why not just do a proper White Balance to begin with and tweak it in post IF it needs it?

[Piotr Wozniacki]

Originally Posted by Dustin Gray

Can someone please explain the benefits over setting manually apart from lazyness?

Dear Dustin, seems you never work in run&gun style. If you did, you would know that following your subject, sometimes you cannot even stop recording, not to mention white-balancing manually each time your subject' lighting changes :)

[Paul Chiu]

my new EX1 arrived a day before i had to film a children play at my kid's school.

i had no chance to read anything, not that i would anyway.

still, at full auto with stupid choice of mine to flip the white balance to "A" when there is nothing there. the EX1 still managed to show the white t shirts correctly under dim and varied stage lighting.

i think after reading the manuals and studying here, the EX1 results will get even better.

full auto samples on 1st day:
http://www.vimeo.com/1109600

http://www.vimeo.com/1108055


paul