Correct white balance

danski

Suspended / Banned
Messages
470
Name
Dan
Edit My Images
Yes
Probably a bit of a noob question, but I keep hearing about using an 18% grey card to set the correct white balance when out shooting.

Can someone please explain how to do this so I can avoid/minimise having to set the correct WB in PP as this gives me varied results, especially when there's nothing white in the pic.

thanks as always
 
As you got a 7D I think you find it work very good on Auto WLB as it measures not only light but colour as well when doing the exposure.
But back to the question Canon you can take a shot with the gray card in the light you are using then in your PP you use this to set all the other photos taken in same light
Or you can take a photo of something white and tell the camera this is white and it will set the wlb for you in camera.
 
Do you have live view or Canon's equivalent? On a Nikon with live view you can set the WB perfectly by simply switching on LV and pointing the camera at something about white then pressing WB and turning the control till the colours on the LCD match those that you can see with your eyes!
 
It doesn't have to be 18% grey. So long as it's a neutral colour, with equal quantities of red, green and blue in it, that will be fine. Clean white is okay - sheet of paper, clean table cloth, you get the idea.

Take a picture of that and use the image as a reference to set the custom white balance - see handbook. Just be careful not to over expose it.

What you are doing is telling the camera that this is a neutral colour, so it measures it and resets the colour balance so that it is indeed correctly neutral. That new setting then automatically adjusts every other colour in the image by the same amount, and therefore they will be correct also.

You can also reference this image in post processing, analyse it and apply the changes in the same way. Some people carry a small 18% grey card and pop it into the first picture of a shoot, then reference it with the dropper in post processing and that gives correct colour corrections for the whole session - so long as the colour of the light doesn't change.
 
Hows that done?

Most image editing software now has white balance tools, one of which allows you to select with a "dropper" and correct the whole image based on whatever cast the sample you chose has. White shirt collars, window frames, tarmac are examples of things to look for, if you've not included a grey or white card in the shot.

You wouldn't want to completely correct in all circumstances. From a review for the Pentax K-7: "Another interesting option is a custom setting that lets you define whether you want the Incandescent white balance setting to completely correct for the lighting conditions or would prefer it to leave some of the colour cast to retain the atmosphere. This is the first time we've seen a manufacturer attempt to address the dichotomy between the technical and artistic requirements of white balance."
 
thanks guys - makes sense

so am I best just leaving the 7D up to its own devices or should I carry a piece of white paper around in my camera bag?
 
thanks guys - makes sense

so am I best just leaving the 7D up to its own devices or should I carry a piece of white paper around in my camera bag?

If you are shooting raw don't worry!

SHOOT IN RAW THEN....

There are three school of though at least

1 - set WB religiously every time using card, camera setting control, LV or one of those filter things.

2 - use AUTO

3 - Set it on DAYLIGHT and adjust whole groups in one go in LR afterwards - ie Say you do a wedding then you might have 20 shots in overcast before the church, 5 shots inside the church, 50 shots in brighter sunlight and then 100 shots in a church hall. You just select the first 20 on mass and slide the slider, then the church shots etc etc....
 
thanks guys - makes sense

so am I best just leaving the 7D up to its own devices or should I carry a piece of white paper around in my camera bag?

Maybe you're worrying too much ;) I always like to get the colour right in camera but TBH I don't have much trouble with it - leave it on auto mostly, or one of the pre-set WB settings.

As pointed out above, white balance can be quite subjective and 'correct' doesn't always look right. You can even argue that correct is not correct because the colour of an object is the light reflected from it, so if it is lit by slightly warm light for example, that's actually the correct colour at that time!

The advantage of correcting it in camera is a) you can very often go straight to output without going near any post processing of Raws :thumbs: and b) most post processing programmes will pick up on the in camera settings and use them as a default already applied to the Raw, so you should be very close even before you start.

I do actually carry a small Kodak 18% grey and white card but hardly ever use it. Just pop it down and take a test pic for reference later.
 
Using white balance to creative effect is great. I like adding a warm tone to my photos by setting what is essentially a slightly incorrect white balance for the conditions. You can create an atmosphere that otherwise wasn't there by fiddling with the white balance a bit. Otherwise, if I am going for more of a neutral "correct" look, auto white balance does it nearly every time.
 
you're right - I think I am worrying too much about this.

I tend to either put it in Sunny Day for those days that the sun does come out or leave it in Auto for the rest of the time then play about with the WB in LR3 - as you say, sometimes an incorrect WB can add some extra warmth to the photo - personal preference wins again

thanks for the advice as always
 
Hi. I shoot raw, so don't tend to worry about it in camera too much. On my compact I usually leave it on auto unless its obviously lighting like fluorescent or tungsten. Auto Color in Photoshop makes changes quite simple as a rule. What is great about the white balance settings is that you can set it to cloudy on a bright sunny day and it will warm up your landscapes quite nicely.
 
Back
Top