ULTIMATE GUIDE TO CUSTOM WHITE BALANCE

[beatman]

Hey guys.
I have a doubt about custom white balance when recording.
I have a Canon T6i.

I am aware on how to:
. take a shot of a gray or white card (or paper)..
. set the camera custom white balance (based on this photo).

My questions are:
1) Should I photometry (is this a word in English, sorry!) my camera when shooting the gray/white card? Which settings on my camera must I use while doing this?
Every single tutorial I’ve been to simply does not talk about this, they just say: “shoot a white piece of paper etc”. **bleep**! lol.
How my camera should be set for this specific part? 

2) Should I use the ‘target’ on the back of my gray card to FOCUS before I shoot the other site of the card (gray part)?

Well…hopefully someone will shed a light on this…

Thanks in advance!

[kvbarkley]

I don't know what you mean by "photometry". Did you read the manual?

It clearly says you want a standard exposure. The important thing is that that your image is not clipped or blown out, i.e., you want the 8-bit histogram to be below 255.

Ideally, you want a white sheet to look like middle gray, which is what "standard exposure" means.

Since we only care about color, the focus is not critical, and in fact a slight blur might be beneficial.

I would just shoot my gray card and fix it in post - especially if you are shooting raw. In fact, this is all moot if shooting in RAW anyway, since the RAW file does not even have a white balance baked in.

[diverhank]

You're right about the instruction not specifying...I think you start out with AWB.  I always do this and the correction after adjustment is always right on. I don't think it matters what mode you use. 

Most often there is nothing for the camera to focus on so I always switch the lens to manual AF then I'm able to take the picture.

[jrhoffman75]

I think this helps:

[beatman]

Thanks for all replies here, extremely helpful! 
Another question, though: I've recently had to film a lecture, and my 18-55 lens couldn't zoom in enough on my subject (i.e: the  white card and the speaker).
What should I do in this case? 
Again (don't know if it was clear): from the place I was with the camera (I couldn't get closer to the speaker, cause it was a lecture and they didn't allow me to stay closer) I couldn't zoom in enough to take a shoot of only the white card (I couldn't exclusively frame it). 

Thanks in advance.

[kvbarkley]

1. Since the light doesn't change you can move the camera closer for just the white balance.

2. Get a larger white balance card like a sheet of poster board.

3. Just set the WB based on the room lighting.

4. If you have only one camera, don't worry about it.

[beatman]

That's exactly what I was looking for: all the alternatives are reasonable and certainly functional.

Thanks a lot! You really helped!

Cheers!!!

[Waddizzle]

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@beatman wrote:

Thanks for all replies here, extremely helpful! 
Another question, though: I've recently had to film a lecture, and my 18-55 lens couldn't zoom in enough on my subject (i.e: the  white card and the speaker).
What should I do in this case? 
Again (don't know if it was clear): from the place I was with the camera (I couldn't get closer to the speaker, cause it was a lecture and they didn't allow me to stay closer) I couldn't zoom in enough to take a shoot of only the white card (I couldn't exclusively frame it). 

Thanks in advance.

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Crop the image.  Although it helps, the grey card does not need to fill the entire image.  As long as the target covers all of the AF points and metering points in the camera, you’re good.  It does not need to go all the way edge to edge.

[kvbarkley]

You can't crop in camera.

[Waddizzle]

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@kvbarkley wrote:

You can't crop in camera.

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Actually, I was thinking of cropping in post.  You can sample the cropped image to create a custom WB setting.