EX1 White Balance Problem?

[Perrone Ford]

Originally Posted by Doug Jensen

QUOTE: "cleaned up my footage beyond belief."

Seriously, you may want to send your camera in for service if white balancing causes that much noise. I'm not kidding. None of the footage from any of my XDCAM camcorders requires cleaning up at all. If you're seeing "beyond belief" improvements then something is wrong. Very wrong.

6db of gain is a lot to me. I know it's not to some people. But I typically shoot EVERYTHING at -3db. the gap from there to 0 is very noticeable and unwelcome. My camera is fine. Looking at my outdoor footage, it's gorgeous. So it's just me being picky I suppose.

[Doug Jensen]

I also shoot everything at -3db. And I don't have any noise problems indoors or outdoors when I white balance manually. It would be impossible for me to take any steps at all that would deliver improvements beyond belief unless my camera suddenly became an F35 or Genesis.

I've manually white balanced every camera I've used in the past 30 years and I will continue to do so. If Panavision says it introduces some tiny amount of noise, that's fine, it's still better than the alternative.

[Garrett Low]

Originally Posted by Perrone Ford

Guys, the way this works is that on daylight balance, there is an equal amount of gain being applied to the R G and B channels. Indoor lighting (incandescent) has a significant lack of blue light. Thus if we leave the white balance setting on daylight, the image appears to shift red, when in fact it's just that there is a lot more red light being emitted than blue. Thus why we gel if we are trying to shift the light blue. If we do a white balance in the camera, all that is happening is we are adding digital gain to to that blue channel to bring it back in balance. This is independent of any luma gain we might add.

OK Perrone. I understand where you are coming from on a color balance theory. But I may have this backwards. If the EX cameras are color balanced for daylight, that would mean that the blue channel has more gain than actual blue in the light source for say tungsten (which has less blue than day light). So, in order to get to white balance when using tungsten sources, we would be decreasing the blue gain. In the video they say, if the camera is balanced for tungsten light, you need to add blue gain to balance. So for the EX cameras which are balanced to daylight, wouldn't we be reducing noise by balancing for tungsten (i.e. reducing blue gain)? Am I totally backwards?

No doubt that it is better to manipulate using 10bit vs. 8bit but that is if you are capturing raw data. In this case you are capturing compressed data, having to uncompress the data, then do the manipulations on your computer. The question is, does the color balancing occur prior to the compression or after processing that compresses the color down to 8bit?

BTW this is actually one of the reasons I fell in love video. It's a great meld of technical and artistic.

Thanks for the link,
Garrett

[Perrone Ford]

Originally Posted by Garrett Low

OK Perrone. I understand where you are coming from on a color balance theory. But I may have this backwards.

Nope. You had it right, I had it wrong. At least from the perspective we are discussing here. I reviewed the Panavision video tonight to refresh myself, and what you are saying is correct.

Originally Posted by Garrett Low

No doubt that it is better to manipulate using 10bit vs. 8bit but that is if you are capturing raw data. In this case you are capturing compressed data, having to uncompress the data, then do the manipulations on your computer. The question is, does the color balancing occur prior to the compression or after processing that compresses the color down to 8bit?

This is why I tested it to see. Would it be cleaner to do it in camera, or not. My experience suggests not, but rather than play the game, I am moving to using lens filtration to solve the problem. That way, I'll have all the blue light in the world hitting the sensors and the gain issue will be come moot. The only problem with that is to be sure there is adequate light available, but that's a far easier problem to solve.

Originally Posted by Garrett Low

BTW this is actually one of the reasons I fell in love video. It's a great meld of technical and artistic.

Awesome isn't it!

Originally Posted by Garrett Low

Thanks for the link,
Garrett

My pleasure. Watch some of the other videos. Fascinating stuff there. Especially, if you enjoy the technical side of imagemaking.

[Garrett Low]

Hi Perrone,

I did start in on the series. Very interesting stuff, at least for me. I started out way back when to embark on becoming a physicist but then changed to engineering but I still love understanding why things work the way they do.

For your CC filters, which ones are you using? One of the advantages I suppose I have is that most of the lights I shoot under are daylight balanced. Also, is there a way to actually turn off any white balance settings or are you just setting one of the presets to the cameras native color temp? If your you just set the color temp do you know what that number actually is?

Thanks,
Garrett