The K stands for a color temperature scale (and absolute temperature scale) measured in degrees Kelvin.
As it stands, your display shows:
5060 (degrees) K, which is approx (ie, near, but a bit short of ) white sunlight.
From the range shown below - 2500-10000, you can set it from approx "a ruddy candle" to approx "blue sky".
Anyway, look it up.
And now, I don't see why you have to particularly "set" it anywhere for about 99% of the time. Are there no
presets, like "Tungsten", "Fluorescent", "Daylight", "Overcast". Usually, pick one of those to suit conditions,
or, leave it as set and if using files, fix it in the converter.
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Oh, then to add...
Once you have set that (or any of the presets), that color temperature becomes your "white".
CC, Image editing OK.
White balance - One of the more mysterious aspects of photography IMHO.
K = Temperature in degree Kelvin. A temperature scale where 0 is at absolute 0 or -273.15 degree celsius.
The 506 you refer to is actually 5060 ie you can't change the last 0. 2500 to 10000 is the range you can set.
The setting affects the colour cast of you photos and is used to compensate/correct for different sources.
I would recommend setting it to auto or using the preset values ie sunny, cloudy, fluro lights etc.
to slow again, beaten by AM above
Agree with Am and Mark. The scale to the right is to adjust the Green (G)/ Magenta (M) balance of the setting.
The temperature above absolute zero at which a black body has to be heated to emit this spectrum of . It is expressed in Degrees Kelvin (°K). IOW, if you heat a theoretical black body to 5400°K, it is the colour temperature of sunlight/daylight - this latter varies depending on one's latitude, time of day, time of year, whether in the shade or full sunlight, etc.
Other forms of lighting have different colour temperatures. Fluorescent, tungsten, etc have both different colour temperatures and different spectra - e.g. fluorescent does not have a continuous spectrum, and has a flicker that will be picked up by electronic shutters in e.g. most mobile phones and many cameras if the latter are set to use the electronic , rather than the mechanical .
Best to use auto WB until you understand what all this means, and what you are doing.
Shooting in has a huge benefit here, as no file has either a white balance or colour space until you assign them during processing.
My galleries contain all sorts of stuff, not just some pretty pictures.
ILCs: E-M1; E-30; E-510; E-1
Digital lenses: 14-42 EZ; 12-50; f/2.8 25 pancake; f/2 50 macro; f/4 7~14; 11~22; 14~42; 14~45; 14~54 MkII; 40~150 MkI; 40~150 MkII; 50~200 MkI; EX-25; EC-14
To elaborate a little on what's already been said:
I agree on the general consensus that using Auto whitebalance(AWB) is the best way to go, but sometimes it's handy to know what whitebalance does too.
With respect to the K numbers(and it is just Kelvin and a K symbol and not degrees Kelvin or °K!!) the higher the number, the more yellow(or warm) the whitebalance setting becomes. This is to counter the more blue as the actual K value increases.
So that a setting of say 3900K in camera, which approximately equates to incandescent , is used to balance the point that incandescent is very warm(yellow).
What you are trying to achieve is a more realistic white colour in your whites by compensating for the colour temp in real world terms.
Same, but opposite, with a setting of (say) 8000K which equates to Shade in camera.
In the shade, the actual rendering of a white colour will be very blue, unless you set the WB to 8000K or shade. So the setting of 8000K adds a lot more yellow to the rendering to balance this blue and your white looks white and not blue!
Hope that makes sense.
As for the tint adjustment. Like John alluded too, it's another compensation for the spectra emitted of various sources, and this is geenrally seen more in fluoro and LED sources as they can vary wildly from the various products.
That is, you can get yourself two different compact fluoro lights(CFL or energy savers), or LED replacements and they may say xxxxK(eg. 5000K or 4000K or whatever) and this may be close to accurate, but where they differ wildly is in the green red(or magenta) colour balance!
And this difference can be quite extreme.
Funny thing is, once you start playing around with whitebalance testing, you may even find you train yourself to be more acute or aware of the differences in tint of various lights in use around the house!
I don't remember 'training' myself to see this in any way, but I notice it a lot when I'm at someone other peoples homes a lot .. looking their lights in use and seeing that one is more magenta, or green or whatever.
For my house I spent a small fortune testing various CFL lights to achieve what looks to me like close to neutral tinted products.
Back in camera, setting whitebalance via the temperature and tint adjustment feature is a little cumbersome.
But if you did want to try to set your own use created WB values, the Pre feature is handy to know how to use.
I assume in a D750 it's the same method as other 's so I'll try that for 'ya.
Firstly find anything at all that is pretty much white grey or black. examples can be anything but you need to be fairly sure they are those colours. White is easy
nuff in that a sheet fo copy paper works well and gives a good . even something as basic as a white t-shirt works too.
Set the WB in the camera to [Pre] and be ready to capture an fairly quickly as it doesn't allow you much time(a few seconds, at best).
While the camera is flashing Pre in the top LCD, you need to take an in half decent .. and the that you want to set WB for.
That is, in this specific you are setting a WB to work with. If you change and the is different(warmth and tint) the use of this Pre value will be out of whack!
Back to the in Pre mode.
The camera will do some calculations for a short time and then give you two readouts Good or No Good on the top LCD again. No Good means you need to take a new as the Pre didn't work.
Good means that the Pre WB setting was accepted and that now you have the WB in Pre mode, your WB is set to go and will be neutral in rendering.
That is, white is pretty much white and there should be no strange colour casts(mainly magenta/green). Test it on another neutral looking item to see how it renders.
Note that you can save this Pre setting for later use again and most cameras allow up to about 5 different Pre values to be stored, and there will be a grid of various images for each of those Pre values to select from too.
It is a bit of stuffing about, and in general there is no need for all of this. BUT!!! sometimes you may want to use it to get as accurate an account of colour in a scene as it may be hard to PP later due tot he various sources(what's called mixed lighting) under which the scene was shot.
This has happened to me a few times, where three different sources were used in the same area(of about 10m). There was one fluoro street (the long thin old style fluoros), one sodium vapour(very yellow orange) and one other high intensity street and they all clashed, in terms of colours being reflected.
So after all of this, and the recommendation to use AWB at all costs, it's good to have an understanding of the processes your camera is actually doing
The next step is to learn how to white balance process in PP.
Which software do you choose to work with?
Arthur, some of us started learning physics long before 1968, so we learned 'degrees Kelvin' as the then correct term ... . And Pluto was still a planet ... .
I am surprised that the D750 only offers WB adjustment along one axis of green/magenta. All my bodies have WB adjustments along two axes - separate ones for the green and amber axes. These adjustments are either local (specific to the WB setting), or global (adjusts all WB settings). The only one of my cameras where this was necessary is my E-30. All the others have been correct out of the box.
Ok, thanks to all of you. Will try and absorb that and guess stick to Auto for the present time.
If you look at this image you will see what I know as the common menu allowing for variation on the "preset" white balances, shady, sunlight, tungsten etc.
Not having handled a D750 I can't say exactly what the menu looks like but according to the illustration on page 177 of the manual it is very similar to other models.
The image that One Click has posted ( post #1 ) is of the adjustment in the menu where one alters the white balance directly by the Kelvin setting and as you would be only too well aware, altering the numbers shifts the amber / blue axis and raising or lowering the sliding scale to the right of the numbers alters the green / magenta axis.
I am more than happy to be informed about this, but it would help if your reference was to something relevant ...
One should also bear in mind that I was expressing my surprise at the apparent situation, not making any kind of statement ...
as per this screenshot.
Likewise, I am always happy to help out those may be uninformed.