Adding WB to the exposure triangle… err… square?

Adding WB to the exposure triangle… err… square?
by eNoBlog on Nov.06, 2009, under Post-processing, Techniques
[http://esfotoclix.com/blog1/?p=847]

If you take control over other aspects of our photography, should you
let the camera automatically select White Balance (WB) for you? Most
if not all cameras come with an Auto-WB mode, and initially, as you
learn to use the camera, it is perfectly okay to let it do its thing.
However, as you perfect your camera skills and start taking control
over the exposure triangle, you need to consider whether you want to
leave WB to chance.

Yes, I said chance, because unfortunately, depending on your camera’s
inner-smarts, from one situation to the next, the colors you end up
getting due to the automatically selected WB setting may be a bit of
an adventure. I suggest that you add a fourth corner to make an
exposure square: WB, aperture, shutter speed and ISO. This will mean,
however, that you will have to determine and set the “correct” WB. How
do you decide this?

Methods for determining WB abound, but before we discuss them here and
in future articles, let’s first examine a foundational choice for
selecting the “correct” WB:

Do you want the colors to accurately reflect the scene as you
photographed it, sometimes called achieving “actuality,” or
Do you want the colors to feel right, as in, for example, making sure
that white is true white and not a color-cast version of white?
Just as with determining the correct exposure one first should decide
how you intend the photograph to look, its purpose, so too you will
need to decide whether you want actuality, namely an exact, accurate
representation of the scene’s colors, or whether you want a different
effect, as when you would want early morning sunlight to be a tad
warmer because that fits the mood you want for your final image.

To keep things simple initially, let’s say you shoot for actuality.
Most cameras have built-in WB settings such as Direct sunlight,
Cloudy, Shade and Flash that you can switch to depending on the
lighting situation at hand. Other settings usually include Fluorescent
and Incandescent, which at least of my Nikons, I have found to be less
than dependable, though I often choose them anyway to get me in the
ballpark. For these and other more challenging lighting situations,
such as when two or more disparate light sources are involved, other
methods may be required.

The brute force method many use rather successfully involves shooting
RAW, then adjusting WB in post-processing. This has both advantages
and disadvantages. On the plus side, you can shoot now and ask
questions later. On the minus side, you have to answer questions
later, often without the benefit of being in front of the scene you
shot to compare your WB adjustments against the actual scene. This is
often acceptable, however. I have found through experience that color
actuality isn’t as big a priority as some would make it. In the end,
it’s about whether the photograph works as a whole, and color,
regardless of how we may feel about it initially, is not always the
overriding factor. Even if the image is about color, having less than
accurate color isn’t necessarily a priority. Besides, probably half of
us are color blind in lesser and greater ways and wouldn’t be able to
agree on what the right color is anyway (think on that for a while).

When you don’t want to guess at color in post-processing, by far the
most reliable way to set WB is with a pre-set shot against a gray (or
white) card. Expo-discs and other like approaches essentially fall
into the same category. Accuracy is a benefit of this approach, but it
isn’t always practical, as when you are changing lighting conditions
often during a shoot (now you’re shooting shady areas, now you’re
shooting sunny fields), or when your subject is lit under light miles
away, and that light source is not available where you are standing.

If your camera has Liveview and features the ability to change WB
temperature, turn on Liveview and crank the WB until the colors you
see in the LCD match the scene before you. This is quick and fairly
trivial to do, but it also depends on the LCD’s color accuracy, which
in the end makes it an approximation – though in my experience it is a
very good one.

Hopefully this information will help you figure out _how_ to set WB.
Now you have to go back to those two options mentioned a few
paragraphs ago and decide _what_ WB you want to accomplish your goal
for a given photograph. Stay tuned for future blog entries for
additional suggestions and illustrations how one might approach WB
selection to meet each photograph’s needs.

On Fri, 6 Nov 2009 11:22:53 -0800 (PST), eNo <grandepatzer@gmail.com>
wrote:

>
>If you take control over other aspects of our photography, should you
>let the camera automatically select White Balance (WB) for you

Auto white-balance is generally a poor idea for the professional
photographer. So is setting white-balance off of a gray card or using an
expodisc if you wish to present realistically looking images. The camera's
auto white-balance is set by whatever overwhelming hues might appear in
your FOV. Even changing focal-lengths will change the white-balance because
it will include or discard other areas of the scene which are providing the
white-balance cues to the camera. Take a group photo and white-balance may
be acceptable, zoom-in and single out that one friend in the red shirt and
his skin-tones will now shift too green.

Auto white-balance (or setting balance off a gray card or expodisc) will
also wipe out the intense colors of a sunset, muting them all into
something nearer to a neutral white-balance. It will wipe out the ambient
green light filtering through a foliage canopy, giving the subjects
photographed under those trees an unnatural appearance, unnatural looking
to anyone who has ever walked in the woods to have a real-life comparison.
Also wiping out the warm gold and reddish hues that are expected when
walking through the woods in fall. Images taken before dawn or dusk will
also lose their naturally bluish and magenta appearances due to the ambient
light's colors. Instead of looking as they do in real life they will look
like underexposed images taken at noon if you use auto white-balance
methods.

Auto white-balance is an okay crutch for snapshooters, not very useful for
pros. The only time I have ever found it very handy was when shooting
subjects under a variety of combined lighting sources; neon, UV lamps
(filtered and unfiltered), incandescent, sodium, and various fluorescent
lights (daylight, warm, and full-spectrum, etc.). In that nightmarish mix
of artificial light-sources auto white-balance can settle on something
tolerable, but will still need some tweaking in editing. What situation
would ever have that many lighting sources strongly impacting the subjects
all at once? When I was doing my own studies on what species of
night-flying insects were drawn to which light sources and under differing
intensities of those light sources. Documenting individuals and groups of
specimens at varying degrees of macro-photography ratios.

On Fri, 06 Nov 2009 15:49:33 -0600, My POV <mypov@myaddress.com>
wrote:

>On Fri, 6 Nov 2009 11:22:53 -0800 (PST), eNo <grandepatzer@gmail.com>
>wrote:
>
>>
>>If you take control over other aspects of our photography, should you
>>let the camera automatically select White Balance (WB) for you
>
>Auto white-balance is generally a poor idea for the professional
>photographer. So is setting white-balance off of a gray card or using an
>expodisc if you wish to present realistically looking images. The camera's
>auto white-balance is set by whatever overwhelming hues might appear in
>your FOV. Even changing focal-lengths will change the white-balance because
>it will include or discard other areas of the scene which are providing the
>white-balance cues to the camera. Take a group photo and white-balance may
>be acceptable, zoom-in and single out that one friend in the red shirt and
>his skin-tones will now shift too green.

....is that "to green" or is "too green" intended?
>
>Auto white-balance (or setting balance off a gray card or expodisc) will
>also wipe out the intense colors of a sunset, muting them all into
>something nearer to a neutral white-balance. It will wipe out the ambient
>green light filtering through a foliage canopy, giving the subjects
>photographed under those trees an unnatural appearance, unnatural looking
>to anyone who has ever walked in the woods to have a real-life comparison.
>Also wiping out the warm gold and reddish hues that are expected when
>walking through the woods in fall. Images taken before dawn or dusk will
>also lose their naturally bluish and magenta appearances due to the ambient
>light's colors. Instead of looking as they do in real life they will look
>like underexposed images taken at noon if you use auto white-balance
>methods.

....I shoot RAW and wrestle with WB in post, but I'm inexperienced
enough to ask this: Does the WB I set in-camera have any effect
whatsoever on a RAW file?

cg
>
>Auto white-balance is an okay crutch for snapshooters, not very useful for
>pros. The only time I have ever found it very handy was when shooting
>subjects under a variety of combined lighting sources; neon, UV lamps
>(filtered and unfiltered), incandescent, sodium, and various fluorescent
>lights (daylight, warm, and full-spectrum, etc.). In that nightmarish mix
>of artificial light-sources auto white-balance can settle on something
>tolerable, but will still need some tweaking in editing. What situation
>would ever have that many lighting sources strongly impacting the subjects
>all at once? When I was doing my own studies on what species of
>night-flying insects were drawn to which light sources and under differing
>intensities of those light sources. Documenting individuals and groups of
>specimens at varying degrees of macro-photography ratios.

On 2009-11-07 00:13:59 -0800, Charlie Groh <chasgroh@dslextremerage.com> said:
<-------------------------------------------------------------------------------------------->
....I

> shoot RAW and wrestle with WB in post,

Me too.
> but I'm inexperienced
> enough to ask this: Does the WB I set in-camera have any effect
> whatsoever on a RAW file?

As far as I know, no.

--
Regards,

Savageduck

On Sat, 07 Nov 2009 00:13:59 -0800, Charlie Groh
<chasgroh@dslextremerage.com> wrote:

>On Fri, 06 Nov 2009 15:49:33 -0600, My POV <mypov@myaddress.com>
>wrote:

>>white-balance cues to the camera. Take a group photo and white-balance may
>>be acceptable, zoom-in and single out that one friend in the red shirt and
>>his skin-tones will now shift too green.
>
>...is that "to green" or is "too green" intended?

"too green", intended.

>
>...I shoot RAW and wrestle with WB in post, but I'm inexperienced
>enough to ask this: Does the WB I set in-camera have any effect
>whatsoever on a RAW file?
>

It depends on what RAW editor you use. RAW files usually get white-point
flags set in the RAW file header info. (Typically recorded as multipliers
to the red and blue channels were green = 1.00000000.) In your editor you
can usually choose to select whether the editor honors those RAW file
white-point flags or ignores them and does its own auto white-balance
setting. Editor options usually labeled as "Camera", "Auto", or "Custom".
The "Camera" option taking the white-point cues from the RAW file header
info. Most editors on their default settings honor those white-point flags
as a good starting point. Some unconventional RAW files, like those created
by CHDK cameras, have no header info and do not contain any white-point
information so it's usually a good idea to let your RAW editor set its own
auto white-point for a good starting point.

On Sat, 7 Nov 2009 02:04:07 -0800, Savageduck
<savageduck1@{REMOVESPAM}me.com> wrote:

>On 2009-11-07 00:13:59 -0800, Charlie Groh <chasgroh@dslextremerage.com> said:
><-------------------------------------------------------------------------------------------->
>...I
>
>> shoot RAW and wrestle with WB in post,
>
>Me too.
>> but I'm inexperienced
>> enough to ask this: Does the WB I set in-camera have any effect
>> whatsoever on a RAW file?
>
>As far as I know, no.

And this information coming from someone who professes to be an experienced
photo editor, DSLR expert, and RAW-always-required fanboy.

Too funny.

What was that I was saying about all DSLR proponents being total idiots?
It's why they select the cameras they do, the same amount of ignorance and
stupidity is applied to their camera buying decisions.

Well, good thing they're not the only ones hanging around these newsgroups.

On Sat, 07 Nov 2009 00:13:59 -0800, Charlie Groh
<chasgroh@dslextremerage.com> wrote:

>On Fri, 06 Nov 2009 15:49:33 -0600, My POV <mypov@myaddress.com>
>wrote:

>>white-balance cues to the camera. Take a group photo and white-balance may
>>be acceptable, zoom-in and single out that one friend in the red shirt and
>>his skin-tones will now shift too green.
>
>...is that "to green" or is "too green" intended?

"too green", intended.

>
>...I shoot RAW and wrestle with WB in post, but I'm inexperienced
>enough to ask this: Does the WB I set in-camera have any effect
>whatsoever on a RAW file?
>

It depends on what RAW editor you use. RAW files usually get white-point
flags set in the RAW file header info. (Typically recorded as multipliers
to the red and blue channels where green = 1.00000000.) In your editor you
can usually choose to select whether the editor honors those RAW file
white-point flags or ignores them and does its own auto white-balance
setting. Editor white-point options usually labeled as "Camera", "Auto", or
"Custom". The "Camera" option taking the white-point cues from the RAW file
header info. Most editors on their default settings honor those white-point
flags as a good starting point. Some unconventional RAW files, like those
created by CHDK cameras, have no header info and do not contain any
white-point information so it's usually a good idea to let your RAW editor
set its own auto white-point for a good starting point.

On Sat, 07 Nov 2009 05:41:41 -0600, My POV <mypov@myaddress.com>
wrote:

>On Sat, 7 Nov 2009 02:04:07 -0800, Savageduck
><savageduck1@{REMOVESPAM}me.com> wrote:
>
>>On 2009-11-07 00:13:59 -0800, Charlie Groh <chasgroh@dslextremerage.com> said:
>><-------------------------------------------------------------------------------------------->
>>...I
>>
>>> shoot RAW and wrestle with WB in post,
>>
>>Me too.
>>> but I'm inexperienced
>>> enough to ask this: Does the WB I set in-camera have any effect
>>> whatsoever on a RAW file?
>>
>>As far as I know, no.
>
>And this information coming from someone who professes to be an experienced
>photo editor, DSLR expert, and RAW-always-required fanboy.
>
>Too funny.
>
>What was that I was saying about all DSLR proponents being total idiots?
>It's why they select the cameras they do, the same amount of ignorance and
>stupidity is applied to their camera buying decisions.
>
>Well, good thing they're not the only ones hanging around these newsgroups.

Savageduck is quite correct as far as the NIkon cameras with which I
am concerned. The RAW data is not affected by any of the camera
settings. The settings will affect JPG or TIFF files produced from the
RAW data.

Also, when processing Nikon RAW files in the Nikon NX2 editor, NX2
will use the camera settings to render the image presented to you on
the screen. However you can change these during the editing process.
Again, none of the editing changes have any affect on the RAW data,
which remains as it was produced by the camera.



Eric Stevens

Charlie Groh wrote:
> ...I shoot RAW and wrestle with WB in post, but I'm inexperienced
> enough to ask this: Does the WB I set in-camera have any effect
> whatsoever on a RAW file?

No. The camera saves the WB setting that you select, but it doesn't
affect the actual image, & many RAW processors will ignore it.



--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------