Auto white balance = optimal H264 recording quality?

[JSwift2046]

Hi,

Apologies if this is an old issue, or if I'm missing a few things.. I'm using a 5Dmkii, and Magic Lantern runs perfectly.

I'm trying to get optimal recording quality with H264. So I'm trying to make the most of the full 8-bits per channel when recording.. Obviously recording with Auto White Balance can be problematic for consistency, but what I notice is AWB seems to produce a brighter recorded image than any of the custom settings..

If I'm assuming correctly, this is because it's setting the white point in a way that optimises the full latitude of each channel in recording? However if I use custom WB, it seems it sets the white by subtracting colour from each channel (hence the dimmer/darker recording, and less than optimal latitude in recording?).

If this is the case (big if), would it be an option to use AWB, then freeze the internal settings for consistency?

Thanks so much

[PaulHarwood856]

I would honestly use a Gray Card or Cheap version of an Expo Disc for White Balance Consistency. Also, you can set 5600K in daylight, then dial down or up the Kelvin as seen by eye. Indoors, you can set to 3200K, and dial up or down as needed. Here is a link to the cheap, but just as good version of the Expo Disc. I think it will really help you out with Custom White Balance in Magic Lantern settings, not Canon.

Expo Disc: https://www.amazon.com/Ezfoto-Balance-Filter-Olympus-Panasonic/dp/B005MWKKPG/ref=sr_1_17?s=electronics&ie=UTF8&qid=1379810060&sr=1-17&keywords=white+card+for+photography

Gray Card: https://www.amazon.com/gp/product/B00HT9MA1W/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00HT9MA1W&linkCode=as2&tag=techfdinne-20&linkId=LD7INSRMTD75AYVI

    You can also use a white piece of paper, or a grey paint card from Home Depot.

     Hope this helps you out, and please let me know if you have any other questions or concerns.

- Paul Harwood

[JSwift2046]

Thanks so much for that, Paul. I'd not seen the Expo Disc (and haven't quite figured out how it works yet!), but I'll certainly investigate further.

I should experiment with Magic Lantern's white balance more, as it may correct this anomaly I'm finding with Canon's.. To some extent it's not getting a good white so much as getting seemingly better latitude on recording (especially noticeable in low light) using Auto.

[PaulHarwood856]

Hey JSwift2046,

     You're welcome! I would try not to use Auto white balance, since it provides mixed results. There's a setting for custom white balance in the Magic Lantern menu where it reads to expo disc or white paper or gray card. It's very accurate, and if that's a bit cumbersome try 5600K for outside, and tweak the Kelvin. 3200K for inside, and tweak the Kelvin. Kelvin is an amazing tool, and with Magic Lantern is available in the T3i along with the 7D I have. If you are in mixed lighting, say inside, try some of Canon's White Balance Presets, and then make your manual adjustments based on how those presets look. Like for Tungsten lighting indoors, try the Tungsten setting, then match the Kelvin and compare. White Balance is crucial for H.264 recording, and even before transcoding raw to ProRes is crucial to get right in Adobe Camera Raw.

- Paul Harwood