AWB Test

[Melkus]

Was setting here today reading about white balance, you know you can never know enough When I though of doing a little test to see how my camera dose with it's AWB vs Perset vs Custom. All shots was took using a table lamp as my target, all camera settings was left the same other than changing the white balance, I also used my tripod. Camera settings. f2.8 1/60, ISO 400, 18mm, Spot metering, D-range "Off" No Flash and shot in RAW.



AWB. Lots of overcast.



In camera perset. Incandescent



Using custom white balance. White card.

Now I know all this can be fixed in pp but I just wanted to see how it look without any of that. As we can see by photo 1, the camera fails to get it right or even close using the AWB setting. In photo 2 we see a big improvement but still not what my eyes are seeing. In photo 3 using the white card I'm now see what I'm seeing with my eyes here, camera showing 2600K M1. I'm surprised to see in photo 2 with the camera set to it's incandescent perset it gets it close. Now I know that this can all change from camera to camera and that the AWB might do a better job under other conditions but it's something to keep in mind. I did this mainly for the person who just starting out to make them aware of what a impact getting the white balance right can do for there photos Now if you do get it wrong and are shooting in RAW then this can be fixed in pp but for me I like to try to get it right in camera or as close as I can

[Manfred M]

Paul - there is no impact of AWB on RAW files, just jpegs. The colour balance is totally dependent on how you process the RAW files. If you are using the default colour balance with ACR when the file opens, this is probably why you are getting these results.

[Melkus]

Paul - there is no impact of AWB on RAW files, just jpegs. The colour balance is totally dependent on how you process the RAW files. If you are using the default colour balance with ACR when the file opens, this is probably why you are getting these results.

I'm coming up with the same thing if I shoot in jpeg. Here it is again shot in jpeg and like before no pp, all settings the same as before.







So if I'm wrong again help me to understand

[Manfred M]

Paul - a RAW file is just the data recorded by your sensor, no colour temperature correction, no sharpening, no contrast, no saturations, etc. Whatever the sensor recorded is what you got. When you open your file in whatever editing software you use, you have to determine what parameters you wish to set, and programs like the RAW converter that shipped with your camera, ACR, Lightroom, etc. let you do this. The software producer nicely sets some defaults, some come from the camera data while others are just a starting point that the programers have set. A RAW file does NOT have a pre-assigned colour temperature setting, but your software opens it up with a suggested setting, and I suspect that it uses the value that is recorded in the metadata that your camera outputs when it writes the file.

While you are in your RAW editor, you can set the colour temperature to any value you want. Shoot a white balance card or a grey scale card and you can use this to set the right colour temperature, you can adjust the luminace (gamma), etc. Once you save the file (or open it in an image editor), these values are "baked" into the image files (jpeg, tiff, png, etc) and cannot be altered in further editing. You of course will still have the original RAW file and you can start over again. You can still impact the look of the files by changing the colour balance, but it is not the same thing as setting the colour temperature during the RAW conversion process and the colours done post-RAW processing will not be quite as accurate.

So, as I said in my previous post; your RAW editor is assigning specific values to things like colour temperature when you open your RAW file, but this is just a suggested starting point. You can change things to your heart's content. The problem with most cameras is that they tend to do a so-so job in AWB, especially with tungsten light and with fluorescent lights, so this is likely the reason that both your RAW and jpegs look the same. This is why shooters do a custom white balance (CWB) when shooting jpegs or do this in post when shooting RAW. As a jpg + RAW shooter, this is exactly what I do. I use camera presets to try to get the shot right in the camera, and when I post on the internet, I rarely adjust the colour settings. If I don't like the results, I will open the RAW file and work it until I get wha I want.

[Melkus]

Manfred I'm hearing what your saying yet the shots I just took are straight out of the camera jpegs to here, I never open them on my pc. So I'm trying to understand why we are seeing what we are seeing, how and why are they changing from one another Man I love to learn

[groovesection]

When you shoot jpg the camera uses the RAW data and processes this data to create the jpg.(it discards most of the data)
This is why WB (auto/tungsten etc in camera) effect the jpg but not the RAW file.As Manfred said when uou open a RAW file in any software it has to have a base setting, all the data is there but it can only open with a certain setting applied by default

[Melkus]

When you shoot jpg the camera uses the RAW data and processes this data to create the jpg.(it discards most of the data)
This is why WB (auto/tungsten etc in camera) effect the jpg but not the RAW file.As Manfred said when uou open a RAW file in any software it has to have a base setting, all the data is there but it can only open with a certain setting applied by default

Yes I do understand that. So I feel my little test is valid in showing what changing the WB dose.

[Mike Buckley]

when uou open a RAW file in any software it has to have a base setting, all the data is there but it can only open with a certain setting applied by default

Perhaps so, perhaps not, depending on the software. Nikon Capture NX2 (and I assume Nikon View NX2) will render whatever white balance setting was configured in the camera. In other words, there is no "default" setting that then has to be changed by the user to be consistent with the camera's configuration.

[Mike Buckley]

Paul,

Another issue has to do with the quality of a particular camera's auto white balance. As an example, I have a Nikon D80, a D7000 and D5100. The latter two cameras have the same sensor and probably similar auto white balance technology considering that they are in the same generation of models. The D80 is two generations earlier and its auto white balance is not nearly as effective as that of the other two cameras.

[groovesection]

Perhaps so, perhaps not, depending on the software. Nikon Capture NX2 (and I assume Nikon View NX2) will render whatever white balance setting was configured in the camera. In other words, there is no "default" setting that then has to be changed by the user to be consistent with the camera's configuration.

That is what i meant by "base" setting in my previous post, the camera sets the base setting of the RAW file based on the cameras metering/processor when the RAW image is captured on the sensor

[Melkus]

Paul,

Another issue has to do with the quality of a particular camera's auto white balance. As an example, I have a Nikon D80, a D7000 and D5100. The latter two cameras have the same sensor and probably similar auto white balance technology considering that they are in the same generation of models. The D80 is two generations earlier and its auto white balance is not nearly as effective as that of the other two cameras.

Yes and I said so in my frist post that this could change from camera to camera so one would want to check this with whatever there using.

[Mike Buckley]

One more thought: If you get the white balance wrong when capturing the image, it can be fixed whether it's a JPEG or a RAW file. Depending on the software, it might be easier to fix it if it's a RAW file but I wouldn't want people who shoot only JPEGs to think that an accidental mistake with the white balance setting can't be fixed during post-processing.

[jcuknz]

Since I never use RAW I am interested how my cameras record tungsten light and in AWB they give the same result as you got Paul ...I don't know why ... so it is the one situation where I adjust the WB to the little bulb sign.
Why I am annoyed that between models the maker of my camera has moved the rocker switch up about a quarter of an inch and my thumb keeps pressing the AWB button and I have to change back to AWB

[pnodrog]

White balance is ALMOST a myth. The RAW file from the camera contains the colour information existing at the time of exposure. It is our brains that process the colour information subjectively. If you look at an object you are familiar with (a white cat or your hand) under differing lighting it is your mind that recalls the expected colour and adjusts the actual colour to more closely match your expectation. In a sunset we would like a camera to show a white cat as nearly white (we are prejudiced about orange cats) while keeping the full rich warm tones in the sky – our brains can nearly do it, our cameras cannot.


A camera set on Auto white balance has to compromise or use scene recognition software to try and provide an acceptable result. If we intervene by manually setting white balance we are just assuming more control. It does not guarantee a more pleasing result. In the case of a grey card or grey building photographed on a bright cloudy day we can adjust the white balance to make it look as if taken at any time of day we like. If we take it at night illuminated by sodium or mercury lighting we can not easily correct it and if it was a pink or green building unless I liked the new colours I would probably be converting the photograph to B&W.


For me even as a bit of a sceptic of white balance your tests results are not unexpected. But you testing and working out your camera's response to colour temperature and/or white balance is a very worthwhile exercise.

[Melkus]

And that's all it was "A exercise" What you take away from this post is up to you. For me and I'm embarrassed to say that only in the past few months after shooting for so long that I've have become aware of how color temp impacts a photo and can make or break a good shot

[Manfred M]

And that's all it was "A exercise" What you take away from this post is up to you. For me and I'm embarrassed to say that only in the past few months after shooting for so long that I've have become aware of how color temp impacts a photo and can make or break a good shot

I totally agree with you on that statement. If shooting RAW, make sure that you correct the WB in your RAW editor, if shooting jpg, make sure your camera is set up correctly.

Those are easy things to say (and do) if you have relatively pure light, but once you get into a mixed lighting situation, things can get really tricky. If your you are shooting flash in a mixed lighting situation, coloured gels on the flash do help, but if you are in a mixed tungsten / fluorenscent / natural situation, you have to figure out what the best compromise is to get an acceptable look. There may not be a "right answer"....

[gcowan]

Hi Paul,
There is always a lot of discussion about AWB. It is a very interesting issue for which there is no one right answer.

I have been guided to always use one of the fixed pre-sets unless I know what the lighting is, or I can do as you have done and use a card to set a custom white balance. AWB seems to give some very odd results on some cameras. The advantage to my daylight setting, even though I always shoot RAW + JPEG is that I can just apply a standard adjustment in Camera Raw to get to the correct balance for all shots in a set lighting condition. However it doesn't always sort out the issues.

Your post reminded me that I had some photos that would illlustrate a slightly different issue.

On 23 September 2009 Sydney woke up to the mother of all dust storms. It was the peak of 5 to 10 years of drought for our state. The following 3 shots are:
- RAW as shot, re-sized sharpened
- JPEG as the camera saw it based on its expectation of daylight
- Colour adjusted by white balance in Camera RAW based on the known grey of the boat cover colour in the background.







The point of my post is that the correct colour balance as I remember it and from looking at other images from the same day is somewhere between the unadjusted RAW and the JPEG from the camera. There are no easy answers, but the colour corrected version is definitely not an accurate view of the day. The purpose of the picture has to be borne in mind.

Graham

[pnodrog]

Graham, interesting conditions and correction versions. What your memory of the colours on the day would be closer to what nature provided even if the car owners would not like the new colours. Your right - the correct WB adjustment depends on the purpose of the image. It definitely was not me who said photographs don't lie.

I wonder if I can convince my wife that I need a boat and a grey cover to improve my photography.

[Colin Southern]

I think it's important to remember that what a camera captures in terms of the colour of the lighting is always 100% correct; it "is what it is" - and so that's what the camera records. White balancing is a CORRECTION to what the light colour was, to turn the image into something that we want it to be (one that's either technically accurate or one that's visually pleasing).

AWB is the camera's best guess at getting the image technically accurate - other modes just blindly apply a set correction.

In the case of the first 3 shots, AWB has kept a yellow light source looking yellow where as the custom setting has a yellow light source emitting WHITE light. In the case of a lamp, the white light MAY look OK - but as an example, if it were a photo of a couple enjoying a candle-lit dinner, correcting the yellow light of the candle into a white light would probably destroy the "mood" - which means that in this case, AWB would probably have "done a better job" than a custom setting.

[AB26]

Hi Paul,

Manfred tried to explain to me as well that RAW is not affected by WB settings. No matter what WB setting you use in RAW you can change it in PP. A very good and valid reason to shoot in RAW.
I have to agree with you as far as getting it right in camera. I believe there is nothing more satisfying than getting it right in camera.
I shoot a lot, using manual WB, the great danger is forgetting to set WB back to Auto. If you are shooting in JPEG the shots will be ruined.
I must admit, RAW is a bit like a life jacket on a rubber duck on the open see. If you don't use it and fall off, the chance of drowning is too big to risk. Unless of cause you are a Michael Phelps.

We will never get to old to learn.