Are some colour balance settings better than others?

Superzooms Still Win wrote:
Auto white-balance is determined by whatever colors happen to be in the
camera's FOV at the time

You would think so, but it's not that simple and no, I don't know why,
but shooting an orangy-red fabric filling the screen (or whatever)
usually comes out fine.

Dudley Hanks wrote:
When it comes to getting an accurate read on the white in a
picture, how much of the frame needs to be white? The whole
frame? Half? Less?

You need to fill the full frame for setting custom WB in-camera but for
post-processing, you can use any tiny bit of white or neutral gray. It
doesn't have to be exact to help a lot. If there are two colors coming
from each side, the positioning of the gray card is difficult and things
can get messy so try to tilt it to an angle that get's a representative
amount of light from each side. That's usually not a big problem.

I would think any sort of reasonable gray piece of whatever, about
letter sized would work (it doesn't matter if it's in focus, just fill
the screen under the ambient light, and I'm embarrassed that I haven't
bothered with this myself. I do set custom WB in a studio table top
setting when doing macro though. For field work I often wish I'd shot a
gray card when trying to eyedropper around for a neutral spot...

Dudley Hanks wrote:

After I'm done playing with the 500 watt blue bulb, I'll
probably wander on down to a local Canadian Tire store and
check out what they've got for something along that line,
either in the way of LED bulbs, or the worklight type fixture.

Another route is a higher capacity inverter for the car battery. Check
the specs of yours against what's available. I was leaning toward lights
that work naturally at 12 volts, if there's an LED option, that would be
great but the small 12v halogen satellite dish shaped bulbs are common
and directly compatible. I hooked one up in the van and it worked fine.
I also use an inverter and it won't run high demand stuff but the bulbs
designed for 12v should be much more efficient than converting back and
forth. Those halogen bulbs are used in home remodels but that requires
wasting energy to get the wall voltage down to 12v. LED seem to work
with just a few volts with very low draw. It may not be available yet
but a big 12v powered flood light using LEDs ought to be a piece of
cake, at least with cheap 'notchy' bulbs. The cheap little LED
flashlights today are not optimal but are crazy cheap and low demand,
for batteries. I just haven't seen a setup with those making a big flood
on a 12v connector. There are some cheap options for small-battery
powered LED video lights, maybe one of those would work or has a
cig-lighter plug option that's efficient?

Paul Furman wrote:
Dudley Hanks wrote:
When it comes to getting an accurate read on the white in a
picture, how much of the frame needs to be white? The whole
frame? Half? Less?

You need to fill the full frame for setting custom WB in-camera but for
post-processing, you can use any tiny bit of white or neutral gray. It
doesn't have to be exact to help a lot. If there are two colors coming
from each side, the positioning of the gray card is difficult and things
can get messy so try to tilt it to an angle that get's a representative
amount of light from each side. That's usually not a big problem.

I would think any sort of reasonable gray piece of whatever, about
letter sized would work (it doesn't matter if it's in focus, just fill
the screen under the ambient light, and I'm embarrassed that I haven't
bothered with this myself. I do set custom WB in a studio table top
setting when doing macro though. For field work I often wish I'd shot a
gray card when trying to eyedropper around for a neutral spot...



So, my old 18% grey card should work? As long as I fill the
frame...

Dudley Hanks wrote:
Paul Furman wrote:
Dudley Hanks wrote:

When it comes to getting an accurate read on the white in a
picture, how much of the frame needs to be white? The whole
frame? Half? Less?

You need to fill the full frame for setting custom WB in-camera but for
post-processing, you can use any tiny bit of white or neutral gray. It
doesn't have to be exact to help a lot. If there are two colors coming
from each side, the positioning of the gray card is difficult and things
can get messy so try to tilt it to an angle that get's a representative
amount of light from each side. That's usually not a big problem.

I would think any sort of reasonable gray piece of whatever, about
letter sized would work (it doesn't matter if it's in focus, just fill
the screen under the ambient light, and I'm embarrassed that I haven't
bothered with this myself. I do set custom WB in a studio table top
setting when doing macro though. For field work I often wish I'd shot a
gray card when trying to eyedropper around for a neutral spot...

So, my old 18% grey card should work? As long as I fill the
frame...

It's unlikely to be spectrally neutral, like a WhiBal card
(http://www.rawworkflow.com/whibal/).

Dudley Hanks wrote:
So, my question is: Do some settings yield better pics than
others?

Yes. The setting that most closely matches the actual
light you're shooting in gives the best results.

BugBear

Paul Furman wrote:
Superzooms Still Win wrote:
Auto white-balance is determined by whatever colors happen to be in the
camera's FOV at the time

You would think so, but it's not that simple and no, I don't know why,
but shooting an orangy-red fabric filling the screen (or whatever)
usually comes out fine.

The AWB is " determined by whatever colors happen to be in the
camera's FOV at the time", but the algorithms are complex
and sophisticated, and give good (or at least usable) results
for an extraordinary percentage of shots.

BugBear

On Sun, 14 Nov 2010 21:45:24 -0800, Paul Furman
wrote:

Superzooms Still Win wrote:
Auto white-balance is determined by whatever colors happen to be in the
camera's FOV at the time

You would think so, but it's not that simple and no, I don't know why,
but shooting an orangy-red fabric filling the screen (or whatever)
usually comes out fine.

Of course it's "not that simple", but I'm not going to bother trying to
explain it to a moron, other than to tell you that the recorded color of
that orangey-red fabric, if using auto white-balance, will not represent
its original color. If, however, you sample the source-light with a neutral
card and use a custom white-balance, then it will accurately represent the
color AS SEEN UNDER THAT LIGHT ONLY. If the source light is not pure
daylight then it still won't represent its true color.

I'm amazed that any of you can even find the shutter buttons on your
cameras if you can't even comprehend how the simple white-balance settings
can drastically affect the outcome of your images. Funny that you all put
down P&S cameras when all you know how to do is use a DSLR only in P&S
modes, never even comprehending what those P&S modes do.

You're all nothing but useless jokes to the photography world.

On 11/14/2010 11:50 AM, Dudley Hanks wrote:
Going into the colour balance menu of most cameras, there tend to
be lots of choices: sunny outdoors, cloudy, tungsten, a couple
of flourescent variants, and whatever specialty settings your cam
might offer.

But, let's face it, the sensor can only record light that's been
reflected from any given image, and the scene can only reflect
waves that reach it after being emitted from a given
source.

So, my question is: Do some settings yield better pics than
others?

Logic would suggest that the full spectrum of sunny outdoors
light would produce the best final image, since the variation of
light waves would be at a maximum, when compared to the more
selective spectrums of flourescent or tungsten light sources. Or
would it?

I guess what I'm wondering is whether sources of artificial light
are limited in their spectrums, or are they simply constituted of
different amounts of the full spectrum, with a resultant skewed
balance?

If any of this makes sense and you can, er, shed some light on
the subject, I'd be very interested in hearing what you have to
say.

Take Care,
Dudley

The object is to reproduce the way things look to the photographer's
eye. Our eye/mind are very good at adapting to different colors of light
but camera sensors and film are not. That said the various light sources
you mentions all except sunlight are deficient in some color or produce
more of some color than some others.
Fluorescent lamps (except for those that are designed to produce light
that is close to daylight)have an excess of green. Household tungsten
lamps have a excess of red/orange and lack of blue. To compensate for
this digital cameras adjust the white balance to try compensate for the
imbalance. With film cameras filters are used to do the same. For
example with film and fluorescent lamps and magenta filter is used to
reduce the green. You could do that with digital cameras but it's easier
to do it in camera or software. If you shoot RAW, then the white balance
setting is not very important as it is easy to adjust it in the RAW
conversion. In the end the color balance is responsibility of the
photographer not the camera. There is no such thing as "correct" color
there is only what the photographer wants.

bugbear wrote:

Dudley Hanks wrote:
So, my question is: Do some settings yield better pics than
others?

Yes. The setting that most closely matches the actual
light you're shooting in gives the best results.

BugBear


But, if you had a choice of light sources, artificial light
sources in particular, which would you choose to get the most
faithful / widest ranging colours?