Auto white balance

I'm just curious as to why it's better to set the white balance when shooting, versus auto?
It just seems to be more convenient to shoot auto w/b then adjust it in post processing later.
Thanks.

Indeed, but only if you are shooting RAW. I set it to AWB and do all the WB adjustments in the RAW converter. However if you shoot jpg, the WB of the image is processed by the camera and a wrongly white-balanced jpg cannot be corrected in a flexible manner without causing IQ degradation afterwards.

Cheers,

Oh, I'm always in RAW, no doubt.
Thanks for the reply.

jacob smith said:

Oh, I'm always in RAW, no doubt.

Click to expand...

In that case, just include a known 'neutral' colored subject in one test image. That image can be used to white balance all other images taken under the same lighting conditions. You can sample the test image and use the resulting WB settings from the raw-converter software for the other images.

Bart

As Bart said. Use a WB card if colour accuracy is important for a certain shoot. I use a WhiBal gray card myself, certainly recommended.

Cheers,

How does it work, or rather, how would you work it in your workflow?
You have the model or whoever hold it in the area that you're shooting, then in post processing, how do you refer to it?
From what it seems, there's a grey area as well, so it doubles as a grey card (18%)?
Thanks guys, appreciated.

Your raw converter should have a click balance where you just click on the white card.

- DL

jacob smith said:

How does it work, or rather, how would you work it in your workflow?
You have the model or whoever hold it in the area that you're shooting, then in post processing, how do you refer to it?
From what it seems, there's a grey area as well, so it doubles as a grey card (18%)?
Thanks guys, appreciated.

Click to expand...

How it works is explained here (pdf) and here(video).
Basically, you take a shot with the card on it. In the post processing, you use the custom wb picker of your program to find the right wb by clicking with the picker on the card surface. The resulting proper wb values can then be copied to the rest of the shoot.

HTH,

Regards,

jacob smith said:

I'm just curious as to why it's better to set the white balance when shooting, versus auto?
It just seems to be more convenient to shoot auto w/b then adjust it in post processing later.
Thanks.

Click to expand...

Hi Jacob,

Here's my point of view.

A custom calibration will always be far superior since you make a perfect standard by which the camera can deal with all the colors it sees.
WhiBal works very well, but you need to fill the camera frame so get a bigger one so that it will work for your particular lens and then you are set.

Auto will be reasonable or even very good.

Color temp will not work with different light sources at the same "temp" since one also needs distribution of component wavelengths to match too.

WhiBal works very well, but you need to fill the camera frame so get a bigger one so that it will work for your particular lens and then you are set.

Canon is said to works perfectly with white foam core too bu I haven't tested it!

Whatever you set does not limit your ability to adjust RAW images. Use a source for a material known to be neutral. Use the balance dropper tool. Here a tiny target is sufficient in may cases, umless light is uneven with multiple light sources!

Target for white balance: In order of my eclectic preference

1. WhiBal Card


The WhiBal G6 is now available in 3 sizes:
Pocket (2x3.5in)
Studio (3.5x6in)
Reference (8.5x11in)


JPEG shooter can use the new Free WhiBal White Balance Plug-in to correct both White Balance and Exposure on their JPEG captures. Works with all WhiBals that feature TrueBlack™ technology.
Click here for the free download avaialble for either Win or Mac.***

2. Other neutral grey card
3. Concrete wall or side walk
4. White paper good without fluorescent chemical brightener
5. White sheet, tablecloth, shirt or blouse
6. White or gray wall
7. White sclera of eyes
8. White teeth
9. Black objects, better cotton or wool (beware synthetics that have high IR reflectivity!)

Ideally, take your picture and get the color right then! Our job is to take pictures not work at the computer, unless we want to do composites, remove blemishes or add special artistic effects.

Asher

*** If you have a very poor exposure as well you may have to add a "curves" layer and use a low percentage of "multipy" blending to bring back the intensity of the jpg image. A final adjustment of the saturation in "Hue Saturation" layer might be useful.

Auto will be reasonable or even very good.

Click to expand...

In my experience auto WB is fairly accurate for daylight, but not so good for fluorescent or incandescent.

StuartRae said:

In my experience auto WB is fairly accurate for daylight, but not so good for fluorescent or incandescent.

Click to expand...

Yes, that's true. However, all one needs to do is take pictures next to trees and there's a green hue or by a painted wall.

Asher

WhiBal for jpgs using the free software : choose the right light setting!

An extra guide point for shooting with WhiBal for jpg. Use the nearest auto color setting: tungsten, flourescent, bright sunlight, eltectronic flash etc and also include the WhiBal in the shot. Then use the free software downloaded from RawWorkflow.com site as above. It's better to have the jpg closer to the required light before the setting!

Thought I'd mention this extra helpful hint from the website.

Asher

Thanks for all of the previous response, but perhaps I can clarify...

Shooting JPEG.....
1 - ONLY way to get an accurate WB is to a reliable WB reference like a larger size WhiBal (only need to fill the inner circle on Canon camera, not the full frame), or ExpoDisc (used correctly), and create a custom WB within the camera. ONLY way to do it perfectly for JPEG. Do not use White paper or Foam core, as they are not neutral and using white is bad because it is not easy to find a neutral White (Even Gretag white is not good), and shooting White you can run the risk of blowing 1 or more channels which invalidates the WB reference.

2 - 2nd best way for JPEG is to set the WB on the camera to as close as you can get using the presets. Auto WB is NOT ALLOWED because each picture could be shot with a different WB and then batch correction with this method is not possible. Take a WhiBal shot (does not have to fill the frame) in the same light as the other shots. In Post using the WhiBal plug-in you can click to set a very good White balance and then apply it to other photos. Using CS3 (in ACR) or Lightroom...you do not need out plug-in. Both Lightroom and the new ACR can handle JPEGs like RAW and just use the WB tool to click on the WhiBal and apply it to other photos in the same light.

Shooting RAW.....
You can use either way, but #2 is much easier. Both will yield PERFECT White balance settings, where with JPEG, ONLY custom WB will yield perfect WB setting.

You should be shooting RAW. Get my DVD :>) Shipping in 2 weeks...:>)

Thanks Michael for clarifying the matter. I appreciate the point that one only needs to use the central circle on Canon Cameras.

I keep trying to make sure that OPF does maintain a love for non-Canon cameras! We do have many photographer in these categories!

What about Nikon, Pentax or other DSLR's do you have handy the information on these other cameras as whether or not the entire frame has to be filled for custom white balance?

Asher