Approaches in White Balance settings

[nanook]

I like this thread. There are as many views to setting WB as there are photographers. We know how to do it, but there must be a subjective component to the process, as many point out. While tools like ExpoDisc, Colour Passport and greycards can be of great help in the field (especially when there are no clear points of reference in the framed scene - as with those monochromatic scenes, shooting leaves or whatever) - these tools are just a reference or guide.

There are downsides with relying on the aforementioned aids as well:
1) they rely on reflected light and do not measure incident colour temperature
2) this means that you have to measure for each distance, position and angle from subject as the colour temperature can vary enourmously within a single scene and orientation
3) you must calibrate with the aperture used
4) you must calibrate each lens

Simply put, a precise calibration of colour profile (e.g. Passport) and whitepoint (Passport, greycard, Expodisc) can become highly complex if you insist on rendering a scene as "objectively" as possible.

Lately I have started to use a trick that is quite nice with portraits: I find what is the neutral grey in the scene and push the colour temperature 300K up to get more pleasant skin tones with my Nikon. The amount will vary with camera manufacturer and model I suppose.

Especially here up north, I suppose, light varies enormously from minute to minute and especially with a wide angle lens, the orientation can introduce strong polarising effects. I must accept blue snow to get pleasant skintones if the focus is a person, but to get the warm afternoon light in -15 C at mid winter, I run the risk of oversaturation. So - I compromise. If I use more than one lens on the same safari, I also have to adjust for variations in the lenses themselves on how they handle contrast and colour.

Another thing is getting the same colour tone for a series of images. What I do is find a pleasant white balance for one image in a series and copy the WB to the other images taken under the same conditions in the same direction. I push the WB for photos taken under other conditions so that their tonality matches.

Some times I just give up and render in B/W... :P

Shoot in RAW! The purist view of "oh, no, I do not manipulate! I save the image in jpg as I shoot because that is more honest" is just hogwash. Shoot in jpg, nothing against that - but to believe that your camera is better at interpreting reality than yourself is simply underevaluating yourself.

You, as the photographer, hold an image in your head before you shoot it - you try to visualise how to best represent an emotion, a subject, content - whatever. If you shoot in jpg, you must of course be more aware of WB as you shoot, which is a good thing, but don't believe for a second that what your camera shows on the tiny screen under the harsh sun or distracted by that detail called gangrene that is developing on your fingers is the truth and nothing but the truth.

Cheers!

[Manfred M]

There are downsides with relying on the aforementioned aids as well:
1) they rely on reflected light and do not measure incident colour temperature
2) this means that you have to measure for each distance, position and angle from subject as the colour temperature can vary enourmously within a single scene and orientation
3) you must calibrate with the aperture used
4) you must calibrate each lens

Hi Espen – let me disagree with your assertion; when it comes to photography we generally only worry about reflected light. Incident light has no impact whatsoever in determining the colour balance settings. The reason is simple because our cameras are recording the light that reflects from the objects in our images. When it comes to exposure, then reflected versus incident light does come into play, but that is related to the way the built in light meter in our camera works, rather than anything lse


1) they rely on reflected light and do not measure incident colour temperature – this statement is not correct. It’s all about reflected light; no reflected light = no photograph.

2) this means that you have to measure for each distance, position and angle from subject as the colour temperature can vary enourmously (sic) within a single scene and orientation – this assumes that the colour temperature varies by subject and this is really not true in any meaningful way.

If you are in a location where there is a large light modifier, like having a model standing under a tree in the shade or standing near a vividly coloured wall, you really do have a subset of a mixed lighting situation. If you take care of your white balance (i.e. do a custom white balance or take a shot of a reference target), all of your other shots will require the same colour correction. If the sun goes behind a cloud or is setting, then yes, your colour temperature will change and you will have to rebalance.


3) you must calibrate with the aperture used – no; there is no correlation between colour balance and aperture as the wavelengths of light hitting your sensor have not changed.


4) you must calibrate each lens – if you shoot quality lenses from the same manufacturer, chances are this is not correct. In my experience the manufacturers do a very good job in ensuring that their products produce consistent across their entire product range. I have seen some differences between different manufacturers, so if you have a collection of different lenses from different supplies, this could indeed be the case. If you are using an old lens (from the 1960s and before), this could also be true as many of these lenses were designed for shooting with black and white film,

I find your assertion of finding something in your comments about having something in the scene neutral grey and colour balancing against it a bit strange. Unless you have a colorimeter along, how do you know it is neutral gray?

I too live in the north and photograph in the ice and snow. The blue shadows in the snow are reality we have to live with. Unless you are shooting with two hours of sunrise and sunset, the colour temperature does not vary that much, unless the sun pops in and out of the clouds. When shooting people, I will colour balance for skin tones; for the very little skin that is showing on those -20°C / -4°F days tend to have a red flush..

While I understand the advantages of RAW, I’m a jpeg + RAW shooter and probably use jpegs for around 95% of my images. The custom white balance function in my camera works just fine if I don’t like what the auto white balance is doing.

I got into serious digital photography after I got into serious videography (I have been shooting film using SLRs for decades). There is no RAW equivalent in video and on my pro camera, has no auto white balance; so doing a custom white balance is all part of that work flow as well. This has moved into my digital photography workflow as well. As long as I am close in my exposures and white balance, I can tweak this in post-production. If I get it wrong in camera, I have all of the same issues that still photographers have. If I try to correct serious colour issues in post-production, I get artifacts and colour blocking just like I do with a jpeg. Video shots are always compressed, so artifacts are even more of an issue than I get when I edit the high quality jpegs my camera produces.

[nanook]

Nice to get a discussion!

And to be clear, my opinions are my own, not objective truths.

1. Well, as far as I have experienced, shooting away from the sun and towards it gives different tonalities. In studios, one uses lightmeters and calorimeters to measure the colour temperature directly, yes? And indeed, even the instructions for a ExpoDisc gives instructions as to what direction you should point your camera while setting WB (straight up into the sky on a clear day).

2. spelling error omitted, see point 1. I have to adjust wb in extreme situations and yes, mixed lighting is the norm outside a controlled environment. Light scatter of surfaces. A reference target should be placed where your subject is and shot from the angle your camera will be. Colour Passport gives instructions as how to set up a calibrated profile if there is mixed lighting.

3. The iris wide open can give shifts in colours compared to a small iris due to axial colour shifts (green foreground, purple background), lower contrast, purple fringing. Especially true with fast lenses. It therefore CAN affect the measurement, and especially if you use a calibration target (try shooting a Passport at F2.8 and then F11). The WB measurement of your camera will probably not be affected as much. Don't know.

4. All lenses have different personalities, also quality lenses. My Zeiss 15 mm is sharper than anything else I have and does give a different colour profile when shot with calibration target compared to a Nikon 80-200 f2.8. There is also quite some difference between the rendition between lenses from the same producer. So, yes.

All points are details that one should not worry about. My whole point was that there are so many variables in order to get WB perfect, that one must always make concious choices.

As to neutral grey in the scene - how about a grey wall, a reference card or something that I want to be neutral, a white piece of cloth is close enough without resorting to a calibration target. You make a conscious choice as to how the scene should be cast in the final product.

Which is the point - WB is in practical applications subjective. Indeed, the model of 18% grey for metering purposes was as far as I know selected as a statistical average which under most circumstances gives the best result. Measuring WB on a dark, but still neutral point in an image result in a slightly different WB than measured on a light point (even on a calibrated colour target as the passport or higher quality target). Many times we don't want neutral grey but want to keep that golden glow at sunsets.

The human eye is highly adaptive, and not withstanding technological progress, our cameras are dead stupid.

[rpcrowe]

I want to chime in one more time regarding color balance and photography in general.

There are some photographers who have a fetish about recording a scene "exactly" as it was presented at the time of image acquisition. That is a total falacy because, we can NEVER record a scene "exactly" as we see it.

We start to change our perception of a scene as soon as we point the camera to capture a certain part of the image and to exclude other portions. We make a decision regarding point of view, focal length, shutter speed, f/stop, focus, and all of the other parameters involved with the final acquisition.

Then we begin the post processing and can either change the image to something we like better or strive to render a "carbon copy" of the image.

We could now divert this thread into editing subject's faces to make a more pleasing portrait or not! However, I am not venturing into that swamp right now.

I am not shooting images for legal evidence. My images do not have to reflect exactly how the scene that I have captured looked to my eyes as I captured it. What my images have to do is to please me and in doing so, hopefully be liked or admired by other photographers. However, that is secondary to the images pleasing me. Or, if I shoot for clients (for pay or as a volunteer), hopefully the images I produce will be liked by my clients.

[rambler4466]

Wow! Great thread here, but what does it all mean for us rookies? All I know is that when playing around with that WB eyedropper in Camera Raw a so-so image has suddenly jumped to an image worth saving. Or if I decide to shoot a night photo in Tungsten, I get a pleasing blue result. If I experiment by pre-setting temps of white balance and taking images of the same subject in sequence only a few seconds apart, I get a lot of different looking images and the one that looks 'best" to me is the one I choose. Warming up white balance setting before you take a photo of a sunset or shooting a landscape in the dark can have pleasing results, too.

Remember, are we taking photos or making images? Our images are extensions of ourselves and what emotions or feelings we are trying to convey. An artist (painter) fills a blank canvas. An photographer has a full canvas and then decides how best to portray what is in it. How? He uses the "tricks" of the camera. Maybe its with the variety of exposures, or maybe a tilt of the camera or a different angle of view or maybe it is just with a choice of White Balance. So, therefore, what is the "correct white balance" or is there really one? If you look at a photo and say. "Oh, he missed the white balance." But, would the mood of the image be different if the white balance were changed? What was the artist (photographer) trying to convey? Is part of an image intentionally blurred or did the photographer just miss the focus? Is the white balance wrong, or did the photographer mean it to be so to create a certain look or emotion?

If you think you have a WB issue try this:

Open the image with the problem in Photoshop
Create a copy of the image by using Image > Duplicate
Make the copy image active and go to Filter > Blur > Average. (This will turn the copy image into a monotonal nothing. If the image was perfectly neutral, the averaged image would be medium gray. More likely, you will see that it has a defined color cast. That is fine for our purposes.)
Select the original image to make it active and arrange the two images so that you can see them at the same time.
Add a Levels Adjustment layer to the original image.
Click on the middle eye dropper (the middle gray) in the Levels Adjustment samplers and click once on the averaged (blurred) image. You should see an immediate shift to a more pleasing color.
You can now close the copy image without saving as it has served its purpose.

(This was a Photoshop tip about color cast from a member of a local camera club)

[Manfred M]

Frank - there are a number of similar techniques and they work fine if the image is "average"; the "flaw" in the technique is that it only works if the scene is indeed "average", otherwise you will get colour casts. Think of a bit like the way your camera's reflective light meter can get fooled.

A similar technique that is a bit faster is to take your blurred / averaged layer, then invert it and use the Multiply blending mode on that layer. The resulting image will be neutral, albeit with the caveats above.