What are the RGB values that correctly represent a 5800 K white surface on a calibrated 6500 K monitor?

Question

Consider a high-quality monitor calibrated at the standard parameters: 6500 K, 2.2 gamma, 120 cd/m^2. Calibration is accomplished with a LaCie hardware sensor + its software, and it's quite accurate.

I intend to take a picture of the Sun through a telescope, using a safe, dedicated solar filter (full aperture Baader solar film for telescopes). The Sun's temperature is 5800 K. The filter is "white", quite decent actually, but I'm sure it's spectrum is not 100% flat - rigorously speaking it cannot be. Also, the camera may capture some infrared and so on, and further alter the color of the solar surface.

I want to process the resulting image so that, on the calibrated 6500 K monitor, the Sun's color is represented as close to original as possible. I expect the result to look like a soft creamy white.

Basically, that boils down to representing a 5800 K "white" on a 6500 K monitor. How do I do that?

I could load the image and tweak the tint settings (white balance) in software until the RGB triads on the solar disk fall in the required range, but I don't know what that range is. Sounds like there should be a formula for it somewhere ("given T1 the temperature of the monitor, then T2 white is represented when xR + yG = zB" or something like that, I'm just making stuff up).

Another approach: it would be nice if there was an app that could just generate "white" at any temperature, given that the monitor is calibrated at a certain color temperature. Then I could compare the generated white with the Sun's image, and make adjustments. But I'm now aware of any such app.

Any suggestions?

I do most of my raw file processing in Lightroom, I can use GIMP for additional color channel tricks. I'm not a photography expert, obviously, but I can follow directions. :)

Thanks!

Asked by Florin Andrei

Answer

The answer is: sRGB = (255, 241, 234).

The details of the calculation:

I calculated the spectrum of a blackbody at 5800 K using the Planck’s formula, then multiplied by the CIE color-matching functions of the standard 2 degrees observer and integrated over the wavelengths to get the (X, Y, Z) color. I then divided by X+Y+Z to get the chromaticity:

(x, y) = (0.3260, 0.3354)

multiplying (x, y, 1-x-y) by the XYZ to sRGB matrix, and dividing by the greatest component (R) yields:

(R, G, B) = (1, 0.8794, 0.8267)

I then gamma-encoded, multiplied by 255 and rounded to the nearest integer and got:

(R’, G’, B’) = (255, 241, 234)

Caveat: My answer is in the sRGB color space, which is almost, but not quite 6500 K with 2.2 gamma. BTW, “6500 K with 2.2 gamma” is not a color space specification: you also need the chromaticities of the primaries to get a fully-specified color space.

Answered by Edgar Bonet

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What is the best free software to edit NEF photos?

Question

I'm new to photography and just starting to take photo in RAW format. I haven't found a difference in quality of color adjustment editing between ViewNX (free software coming with my Nikon d5100) and Picasa, perhaps because of my inattentiveness. So I've decided to ask here what is the best free software to get most from RAW (Nikon NEF) photo editing?

Asked by yura

Answer

For the Mac, the best editor that will get the most (but is not exactly easy to use) is the Raw Photo Pro processor. It can do pretty much anything to maximize the raw potential. But if I may, I think that's going down the wrong path. You can get a little extra quality from processing the raw differently (I'm intentionally excluding post-raw conversion editing) but far more quality from how you setup the shot. Change in lighting, filters, angle, exposure, etc. can dramatically improve a picture more than subtle raw conversion improvements.

Even still, once a photo has been converted there is a world of changes you can do to an image that has far more ability to change perceived quality than what is done through raw conversion.

Answered by nwcs

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Does this sunrise photograph have a problem with white balance?

Question

I find this scene "all" "Orangey". The trees are also looking a kind Orangey.
Is the colour balance wrong? Or it is normal for a sunrise scene?

http://1x.com/forum/bookmarked/32030/critique-on-photo-september#

Asked by Anisha Kaul

Answer

White balance is all relative. Light (natural or artificial) varies in colour and your eyes are used to adjusting it. It's amazing how an image can seem fine until you see another image with a different white balance and it suddenly looks wrong. Even the background colour of the page holding the image or frame can influence how colour balance is perceived.

With this is mind there is no correct white balance. The only sense in which the white balance can be "wrong" is relative to the intent of the image. If you intend to create to invoke the feelings of a warm sunny day and your image has a strong blue cast then it is probably that a mistake has been made.

With reference to the image you posted, it is not a documentary photograph but an impressionistic depiction of the scene. In my opinion the colour balance is in keeping with the style and content of the image.

Answered by Matt Grum

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How to set white balance when there's no neutral region to select with the eyedropper?

Question

If, in an image, there is no region which is neutral white, grey or black, how to set white balance?

Asked by Paolo

Answer

You can mimick auto white balance using Photoshop's Average Blur filter in a duplicate throw-away layer. This will determine the overall color cast in the image. Then add a curves adjustment layer, use the gray point eye dropper and click on your average blur layer, which will turn it to grey. In other words the curves layer will neutralize that color cast. Then remove the average blur layer, and the curves layer will make that same adjustment on your overall image.

This is basically what your auto white balance does in camera. Samples all the light coming in and adjusts.

If your image is a close up of skin (red) or a forest (green), then the light should have a red or green cast to it, so this technique may overdo the adjustment (so may your auto white balance). If so adjust the opacity of the curves adjustment. It will at least point you in the direction of removing the dominant color in the image.

So the steps again are:

• duplicate your layer in Photoshop

• in the top layer, Filter > Blur > Average

• add a curves adjustment layer

• use gray point dropper, select the color in the average blur layer

• delete the average blur layer

• adjust opacity of curves layer

Answered by MikeW

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Is a white sheet of paper as good as grey card?

Question

Can I use a white sheet of paper instead of the grey card for white balance calibration? I actually tried and it works not bad at all. I know the grey card is calibrated etc, but does it really cahnge?

Asked by Paolo

Answer

A purist would say it's not good enough because you can't guarantee the consistency of the white in the paper. However in my personal experience it's plenty good enough. I've used sheets of paper, bleached coffee filters, tops of Pringles cans (when they had a frosted top) and everything was fine. I've also used more expensive tools like the CBL Lens.

However, a word of caution: if your goal is color accuracy then it's not good enough. You need proper tools. If your goal is to get very close then it's perfectly fine to use paper. Remember that in many cases a white balance choice is an artistic choice more than anything else. And there are many reasons to choose something other than what is technically correct.

Answered by nwcs

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Should I be warming grey card calibrated shots?

Question

In a recent blog post at this site, Tim Grey recommended the following:

You could then use the white balance tool in Lightroom or Adobe Camera Raw (or similar tools in other software) to make the gray card appear perfectly neutral, and then simply adjust the Temperature slider to shift between blue and yellow. For the “typical” photograph that would involve increasing the Temperature value to add a little warmth to the image.

After reading other questions about using a grey card on this site, I do not see anyone else recommending "adding a little warmth" back in after using the white balance tool off of a grey card. Is this a typical practice? Do grey cards produce cooler colors then most scenes require?

Asked by dpollitt

Answer

I usually find, especially when dealing with artificial light, that an image that is white balanced that accurately is often cool and I tend to find it a little harsh as a result, so I've been known to warm up the image a little either with the white balance tool or a filter in Photoshop afterwards.

I would note that it wasn't all that rare with film, which was white balanced for appropriate light, to use warming filters to make it a little more pleasing, especially with people in the image. Cooling filters also existed, so it is entirely dependent on the look you want to achieve as to how you would filter.

At any rate, skin tones tend to look better if the blue is minimized...

Answered by John Cavan

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How to set white balance without eyedropper

Question

If in an image there is no region which is neutral white, grey or black, how to set white balance?

Asked by Paolo

Answer

You can mimick auto white balance using Photoshop's Average Blur filter in a duplicate throw-away layer. This will determine the overall color cast in the image. Then add a curves adjustment layer, use the gray point eye dropper and click on your average blur layer, which will turn it to grey. In other words the curves layer will neutralize that color cast. Then remove the average blur layer, and the curves layer will make that same adjustment on your overall image.

This is basically what your auto white balance does in camera. Samples all the light coming in and adjusts.

If your image is a close up of skin (red) or a forest (green), then the light should have a red or green cast to it, so this technique may overdo the adjustment (so may your auto white balance). If so adjust the opacity of the curves adjustment. It will at least point you in the direction of removing the dominant color in the image.

So the steps again are:

• duplicate your layer in Photoshop

• in the top layer, Filter > Blur > Average

• add a curves adjustment layer

• use gray point dropper, select the color in the average blur layer

• delete the average blur layer

• adjust opacity of curves layer

Answered by MikeW

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What white balance settings do I need to capture the cast of a coloured streetlight?

Question

I want take a photo of a scene lit by a yellow-orange street light. Unlike many of the questions here, I don't want to balance the colours in the scene, rather I want the areas lit by that light to remain yellow. The street light is the dominant light source in the scene.

What white balance settings do I need to capture the cast of a coloured light?

Asked by fmark

Answer

Try sunlight. That'll give you a fixed setting which will assume a relatively "hot" light source, which will render the more-yellow light sources as yellow in your image. (Conversely, if you shoot actual sunlight in incandescent-wb, you'll get a strong blue cast.)

If your camera (or RAW processing software) allows you to set color temperature in Kelvin, try setting it around 5000, and adjust up and down to find the cast that looks right to you.

Aside: Somewhat unfortunately, the numbers used for color temperatures come from science rather than art, so hotter light is more whitish blue, and cooler light more yellow-red — the opposite of our natural sense of white/blue as cold and red/orange/yellow as warm. Oh well; just more functional jargon to learn. Rather than going into it in much more detail in this answer I'll just point to another couple of questions: What is color temperature and how does it affect my photography? and What is the meaning of White Balance, which have good information on the topic already.

Some built-in WB presets will also adjust on a magenta-green scale, which isn't taken into account by color temperature. This is important when photographing under some fluorescent lighting. If you're shooting under high-pressure sodium-vapor lights (like many streetlights), with their characteristic pink-orange glow, you're pretty much out of luck in getting any natural looking balance, because the spectrum is so narrow and strange. In that case, going with a daylight preset and just preserving the odd look may be best. Or, deciding not to worry about it and going to black and white.

Answered by mattdm

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How can I tell if a reflector is pure white?

Question

I want to use a piece of fabric as an inexpensive reflector.

Is there any way to find out if it is pure white, so that I can be sure it will not add a colour cast to the light it reflects?

Asked by AJ Finch

Answer

There are a few things you could do:

• Compare it with a reflector that is known to be pure white (a purpose made white balance card would be good for this).
• Take a photograph of it with a light source of (approximately) known colour temperature (e.g. the sun) and spectrum and do a raw conversion with this colour temp and look at the RGB values.

The first method will probably be a lot more reliable as it won't succumb to lighting colour shifts or the vagaries of Raw processing. However, provided it's not massively off (in which case you'd be able to see that clearly) it probably doesn't matter if it's pure white.

Colour temp is relative so the only time it matters is if you're using it alongside other light modifiers which are pure white, so my suggestion, if this is the case, would be to try the first option and compare it to your other modifiers either by eye, or better by shooting images of them under controlled lighting.

Answered by Matt Grum

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What does it mean when Dpreview says “White balance often excessively orange under artificial light”?

Question

From: http://www.dpreview.com/reviews/nikond3100/page19.asp

White balance often excessively orange under artificial light.

Artificial light here may also mean Flash.
Is this something which I should be concerned of if I have to purchase this camera or is this "normal" and can be "easily" adjusted by reading this: How do I properly white-balance my photographs when I'm shooting in mixed-lighting environments? ?

Is this a factor on which one should/may decide not to purchase this model?

Asked by Anisha Kaul

Answer

No it is not a big concern and usually does not mean flash since flash is daylight balanced.

What it means is that when you use the automatic white-balance option, things will come out too orange under artificial light, mostly incandescent lighting.

There are plenty of ways around which mean different amount of work:

• Use Custom White-Balance: You shoot a known white target first and then all your shots in the same lighting condition come out perfect.

• Use Preset White-Balance, possibly with Fine-Tuning: You set the white-balance to current type of lighting which gives you better results but not necessarily perfect.

• You shoot RAW and the white-balance problem is delayed. You then set the WB according to taste or use a known white object (ex: shoot of a reference WB-card) to set the WB to images in batch shot under specific condtions.

Answered by Itai

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Why is custom white balance in Canon DSLR's so cumbersome?

Question

I've always wondered why custom setting the white balance in Canon dslr's (focus on white surface, take picture, goto menu, goto define custom white balance, choose picture, validate) is so much more annoying then custom WB on, say, entry-level professional video cameras (focus on white surface, push "custom WB" button) ?

After scouring the web for other techniques or ways that I could have overlooked, seems there's no easier way to set custom WB on Canon.

For Nikon users it seems simpler, yet not quite as simple as in video cameras: you have to be in some 'PRE' mode and just shoot a white surface.

Or am I missing something and custom WB is just a not so much used feature for photographers, and I'm just spoiled by my experience with video cameras ?

Asked by Berzemus

Answer

I was also wondering why the setting is created this way, then a senior photographer explained to me that it has several reasons:

• this way, the calibrating image is saved on your memory card and you can capture more of them, one for each scene and then eventually swith between them (however, I find this quite uncomfortable as I would need to browse the card a lot and I often use more then one card, so the calibrating image might not be saved on my actual card at all)
• the main reason I suppose is that it keeps it saved for post-production. If you accidentally change your WB settings (and that can happen very easily, because Canon camera remembers WB settings for each capture mode individually), the whole rest of the picture set can go wrong and you need to repair WB settings in post-production. In that case, you can load the calibrating image and correct pictures with its help in a much easier way. Otherwise you would need to guess the WB and the result would depend on your screen setting, PC-room light conditions etc.

BTW, I can recommend using a WB calibration cap - it is very small (it has the same size as a filter), it is made from a white translucent plastic and works like a charm. Much more comfortable to carry around than a white balance card, toilet paper or whatever. You just need to take a picture with this cap on your lens using manual focus and the result image can be used as the WB calibrating image.

Jakub

Answered by Jakub

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Do the preset picture styles also affect the White Balance?

Question

I started shooting RAW with my Canon 550D, and tried out different Picture Style settings on some of the images using the software provided by Canon (I am assuming that the Picture Style settings are consistent with those in the camera). The Picture Style seems to contain only settings related to Sharpness, Saturation, Tone and Contrast.

However, when I switch across different styles, the white balance seems to change as well even though the preset styles seem to differ only in sharpness. E.g. the Portrait style appears warmer than the Standard and Landscape styles.

So, do the preset styles have any impact on the white balance? Also, are there any differences between the camera & computer software styles?

Answer

There are some key differences between a picture style and a white balance setting. While both can affect white and color balance, simply because of the nature of color, the two are intended for different purposes.

Picture Styles affect the baseline curves applied to the image when interpolating the raw bayer pixel information into RGB pixels for viewing on a screen. Picture style curves attune each color channel, introduce stronger contrast over the raw luminence and color information. Its very similar to tweaking the RGB curves in Photoshop, only processing RAW sensor data (individual Red, Green, or Blue bayer pixels) rather than full RGB pixels. The goal is to tune color balance. A classic Color Checker card will help you see the differences between various picture styles, and you can compare the results of a photo of such a card with the card itself or a computerized version (only valid on a properly calibrated computer screen) to see how picture styles affect color balance.

White Balance settings affect the color axis shift of an image. These shifts are primarily along the blue/orange-yellow and green/magenta axes, which are fundamental axes of color theory and human color perception. Most lighting that illuminates a scene is black-body lighting (light produced by dark materials that emit light as a result of being headed to anywhere from 2000 to 20,000 degrees kelvin), so the primary mode of adjusting white balance is shifting the white point along the blue/orange-yellow axes. Some forms of artificial lighting, namely flourescent lighting and CFL bulbs, produce light by running an electric current through a gas. Such lighting often introduces a slight magenta or green tint, and these tints are corrected by shifting the white point along the green/magenta axes.

Both adjustments, tuning RGB curves and moving white point, affect both white balance and color balance, however each affects one much more than the other. A landscape picture style, for example, might introduce a bit more of a green shift in white balance, while enhancing blues and greens from a color balance perspective much more. Correcting the slight green in white balance due to choosing a landscape picture style will affect the overall color balance of the photo as well, however the impact will usually be minor, and the final results are usually still acceptable.

Regarding the subtlety of the changes affected by picture style, thats to be expected, as the differences are fairly subtle. Usually, taking a picture of one single scene with different picture styles will only produce minor differences. On the other hand, taking a portrait with a portrait picture style, and a landscape photo with the landscape picture style, will usually produce better results for those types of photos. The intent of a picture style is to enhance the important color elements of a certain type of photo. Using landscape on a portrait photo probably won't produce anything particularly intriguing beyond a neutral or standard style, while using a portrait style should produce noticeable, even if its only slightly noticeable, improvement in skin tones.

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Why are greycards used for white balance?

Question

I know 18% grey cards are supposed to provide a neutral color to set custom white balance. But why are grey cards used instead of pure white ones?

My assumptions: Is a specific greytone easier to produce than pure white? Does white stain so much easier? (or Does grey just doesn't show stains that much?)

Answer

When you have already set your exposure parameters, white could be clipped in some single color channel (but not all, so your camera won't show it as blown), therefore not being very good basis for color balance adjustment.

Also, paper will turn yellow during time. And just looking at the sheets currently on my desk, there's three different tones of white papers already.

That said, I've used white paper many times and it will get you close enough in all but very critical studio shoots. Very often you'll have multiple different light sources, reflections from colored surfaces and/or shadows vs. lit areas, all having much more impact on colors than slight imperfection in metering the white balance. Just make sure you don't clip any color channels (e.g. by spot metering without compensation from the paper, or verifying exposure parameters using color channel histograms).

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Are scene modes, white balance, color tones, and similar just post-processing effects?

Question

What happens when the following settings are changed:

• White balance
• Color tones
• Scene modes

Are these parameters affect the way in which the photo is taken or they are just applied by processing by camera after taking the image?

Or do these parameters change the way the image sensor records the image?

What about changing the contrast, or sharpness?

Answer

The question What's "real" and what's "virtual" on a (digital) camera? has several answers which list the things which are "real" — that is, the things which affect the capture of the RAW image. To crib from the top answers, these things are:

• ISO
• Aperture
• Shutter Speed
• Focus

with some more technical things like image stabilization and mirror lockup as well.

The answers there don't really cover what's "not real", except by elimination, so let me go over your specifics.

White balance and color tones do not affect these "real" things directly — they're applied to the RAW image in in-camera (or out of camera) post processing. However, it's not quite straightforward, since the selected options can affect the metering — a very blue-shifted white balance might cause a different interpretation of what the exposure should be than a very yellow-shifted one. That, in turn, may make the camera's automatic modes choose slightly different settings. But that's a bit esoteric: the straight answer is white balance and color tones are "after effects".

But "scene modes" are somewhat different, since they apply a whole grab-bag of different settings. Some of these, like a fast shutter speed for a sports mode, will almost certainly affect the real image. Others, like portrait modes, may simply chose post-processing options more suited for delicate-appearing skin.

Your last two, contrast and sharpness, are also an "it depends". These things are strongly influenced by the lens you use, your aperture selected, and correct focus. So in that sense, they are real and unalterable. But, local and global contrast can also be boosted in post-production, and usually is — in fact, usually very much so in the default JPEG output from most cameras. Without that, the out-of-camera images would look much more dull and flat than we are accustomed to. A good camera — or RAW processing software — will give you a lot of individual control over these parameters in the post-processing sense.

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Why does Adobe Camera Raw 6.4.1 offer different White Balance for different photos?

Question

I am using Adobe Camera Raw v6.4.1 to view my Nikon d-90 photos on my computer and when I go to change the White Balance, for some photos I only get the choices:

As Shot
Auto
Custom

Yet for other photos, I get a much larger set of choices:

As Shot
Auto
Daylight
Cloudy
Shade
Tungsten
Fluorescent
Flash
Custom

Why do I see this variation and is there anyway to control it?

Answer

Any image that is not a native RAW format or DNG only provides the basic set of white balance options. This could be JPEG, as well as TIFF, PSD, or any other image format that Lightroom can load. The reason for this is that the full range of white balance and exposure adjustments are only really viable with RAW files to start with, and adjusting any one of the white balance or exposure settings too far will produce undesirable results with any RGB image.

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Can I make my own Expodisc?

Question

I've been contemplating the purchase of an Expodisc to finally be rid of most white balance corrections. The price is a little steep for me, however. I was wondering, is there a way to make something similar to this using materials that one might find 'off the shelf' at a store like Home Depot?

I've tried lenses (prismatic diffusers) from lighting fixtures combined with various translucent plastics without much luck.

Note, the price is not that steep, I'm just one who sticks to a very strict gear budget and I like the satisfaction of making my own stuff.

Answer

From what I understand about Expodisc, it is a rather carefully engineered filter. It is designed to transmit a diffuse 18% of visible light, corresponding to a standard 18% gray card. Unless you have a way to precisely measure the light passing through materials that can be found at the likes of Home Depot, and can ensure that the resulting light is properly diffused, I am not sure you'll have any luck.

I would either buy a set of gray cards, or just bite the bullet and get the Expodisc.

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Why can I adjust the white balance of a RAW file but not a JPEG file?

Question

I recently started setting my DSLR to save RAW files, and using Adobe Lightroom to process them. I still, however, use my little point and shoot camera a lot which does not have an option to save RAW files. I've also noticed that in light-room the white balanced options are different with RAW files vs JPEG files. With RAW files you have the option of choosing from a number of white balanced settings (florescent, halogen, auto etc..), whereas with JPEG you do not. Why is this?

Answer

The quick and short answer:

All images start as RAW files that must have colour balance applied to them.

For jpeg images this transformation is done in the camera using the camera white balance settings. As mentioned above, Lightroom does not have enough information to undo this transformation.

Saved RAW files have no transformations applied by the camera, allowing you, the photographer, to decide later which white balance transformation you wish to apply.

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Will I lose image quality by adjusting white balance in post processing?

Question

I understand that if I shoot in RAW, post processing software like Lightroom are capable of adjusting colour temperature and tint to my desire.

Will I lose any image quality in process? Or is it as good as shooting with correct Kelvin value?

A common example I've encountered: say I shoot with an old flash gun that doesn't communicate with my DSLR, and it is really up to me to adjust White Balance manually. Am I good if I shoot bunch of inbalanced colour photos (most of the cases, blue) and fix them through post processing? Or should I spend time getting the colour right (or close) on the spot and be conscious about changing light so I don't need to re-adjust white balance later?

Answer

No. If you shoot in RAW, there is nothing lost.

In fact, in RAW, the white balance you set in-camera is nothing but advisory information to the post-processing software. A different multiplier is applied differently to the red, green, and blue channels during RAW conversion depending on the setting, and if you're doing that conversion from a RAW file, you can always choose to do it differently unless you destroy the original.

The only exception is when the lighting is so strongly colored that it affects the metering oddly. If you have the white balance set in camera, it will apply to the displayed histogram. Some people really are concerned out about this, and have invented the idea of "uniwb", a custom white balance designed to balance the three color channels evenly. If you are very meticulous, and if you are trying to make the most of extreme scenes, you may be interested in seeing if that helps. (You probably also want to reduce the default contrast settings, for the same reason.)

If you shoot in JPEG only, the application of the white balance multipliers is destructive, and difficult to compensate for if you change your mind. But I don't think that's what you're asking.

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How do I simply adjust the color temperature In Photoshop Elements?

Question

How do I simply adjust the temperature of an image in Photoshop Elements?

Answer

There is a walkthrough of the camera raw white balance feature on the adobe web site.

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What is color temperature and how does it affect my photography?

Question

I have seen color temperature mentioned with regard to white balance, mixing different sources of light, etc., but I haven't come across a clear explanation of what it means to talk about the 'temperature' of light.

How does the color temperature of my light sources effect the images I capture? Are some color temperatures inherently better than others?

Answer

Color-temperature is a way to describe the color of light along a spectrum that goes from warm colors (measured as having a lower temperature) to cool colors (measures as having a higher temperature).

Color-temperature is measured in Kelvin degrees and corresponds to the temperature at which a certain metal must be heated to emit light of that color. That is why lower temperatures (say 3000K) give off warm (yellow-organge) light and that high temperatures (9000K) give off color (blueish) light.

White-balance is the process of canceling the effect color-temperature in a photograph. This is because our brain corrects what our eyes see to let us see white as white, although it may be tinted by the color-temperature of light.

If the color-temperature of light is known, then its effect can be mostly canceled. Automatic white-balance guesses at that temperature (see this question). Preset white-balance use mostly fixed known temperatures (6500K for daylight, 9500k for cloudy, 3000k for tungsten, etc - actual values vary between cameras).

For custom white-balance the camera uses a sample that is known to be white and deduces the color-temperature of light from that. Some cameras actually report the measured color-temperatures when using custom white-balance.

Note that for light sources that are mixed or simply way off from typical lighting conditions (sodium vapor lights, some fluorescents) it is not possible to cancel the effect because some parts of the visible spectrum are missing.

Since colors affect the mood of a photograph and how we perceive images, so does color-temperature. It is known that warmer colors (lower temperatures) are generally perceived as more pleasant and some photographers purposefully set the white-balance wrong to convey a certain mood. Cool colors (higher temperatures) are associated with night and mystery. Neither is better, it must simply fit the photo and how you intend viewers to perceive it.

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