View Full Version : RGB Histogram --> White balance


Guy Godwin
February 11th, 2008, 11:50 PM
Guy's I have strayed away from my XL2 for a couple days. I am putting several items on eBay so that I can buy a couple XL2 toys. (Selling a 16x lens BTW)

...anyway. I was taking some still with my Canon ECS XTi and could not get anything worth a flip. I could use my XL2 and pull out stills with better luck. I have never learned much about the SLR. Shooting my kids outdoors was simple. Auto..Period..perfecto.....

So I decided to spend 24 hours and get to know the unit. It does alot of thing's that I like....

How does this relate to my XL2?

Shooting a white Balance with an 18% gray card on the SLR, I am able to review the photo and all the data. But what I really like is looking at the RGB Histograms and when I review the gray card shots I can see if I am getting an even RGB reflection. As far I know there is nothing on the XL2 to review and confirm the white balance by a colored RGB histogram.

Is this possible?

If not, Why? - I am assuming the 3CCD's have something to with it? I have no idea...Or my other theory was that the still is just that and it is not balanced over time like the XL2.

QUESTION:
What can I do at the shoot to get the image color/quality optimized? How can I check my work as I go? I don't have a monitor that, I assume kills the hope?

Guy Godwin
February 12th, 2008, 12:24 AM
Shooting a white Balance with an 18% gray card on the SLR, I am able to review the photo and all the data. But what I really like is looking at the RGB Histograms and when I review the gray card shots I can see if I am getting an even RGB reflection. As far I know there is nothing on the XL2 to review and confirm the white balance by a colored RGB histogram.

Can I quote my self? Who cares I will anyway.

I think I misunderstood what was occuring on my SLR. If I have an even distribution then I don't need the CWB. (Custom White balance) However, if I am getting an uneven distribution then the XL2 will adjust acordingling? Is this correct?

Does this mean that my final footage will be even? Is it possible to view this distribution of my footage?

Paul Cuoco
February 13th, 2008, 01:25 PM
It's not possible to view a histrogram of your footage on an XL2 without external devices and/or software. The only resaon you can't is because Canon hasn't given us the option in the camera. The closest you can get is using the zebras to check your exposure, and do a manual white balance against a white card.

With external devices you can either hook up a waveform and vectorscope, or you can hook up your XL2 via firewire to a laptop using Canon Console or Adobe On Location software and use the scopes provided in those apps to check your signal in real-time.

Lastly, you could record some footage and then bring it into your NLE to test and look at the historgrams and scopes there. But that doesn't help you in the field.

The most cost effective option currently is a laptop with On-Location. If you can't afford that or the fact that you'd be tethered to a laptop, you'll just have to trust your camera white balance and zebras. In my experience, with careful white balance, exposure and neutral color matrix settings in an XL2 delivers good consistent imagery.