Think about how "Auto" would work-
LR thinks an overall 'Green' image has too much green tint, so it applies the opposite tint- MAGENTA!
If LR thinks an image has too much 'Red' it tries to neutralize by applying opposite- BLUE!
Exactly what you are seeing in your images.
Don't use "Auto", instead (if your monitor is calibrated) use your vision to balance it as you like it.
If you have an area in your image that you know is near mid-tone GREY, use the Dropper/Picker in the WB panel to set WB. (Note- White and Black areas do not work with the picker, as they have equal colour channels 0:0:0 255:255:255, so LR thinks they are already 'balanced' )
And- I could see very little difference in your 3 images of the trees! they all look the same to me. The last dollar bill is definitely 'blue'.
Thanks, that makes sense. I guess where I get confused is how to know if an image really does have too much green tint to it. For example, if I take a picture of my office wall (which is all pale green), AWB will want to add a lot of magenta tint to the image. In this case, I would say it's incorrect because the wall really is green. On the other hand, if I have a white wall, but I illuminate it with a green light, then neutralizing that color is the correct thing to do (unless I really want the wall to appear green).
A more practical example is shooting wildlife in the woods. Here's a real-life example.
This was taken with the daylight preset. I think the color temp could be bumped up a little, but aside from that, it's very green. AWB will want to add a bunch of magenta to this image. In cases like this, it seems to make the deer look better, but it also takes away from the natural ambiance of the scene.
When I play around with images in LR, the AWB seems to add too much magenta, maybe taking the tint from zero to +30. Often times, it seems like the best setting is somewhere in between. In the end, does this just come down to personal preference/artistic vision? In the image above, I can either leave it as is (close to how I remember it looking in real life) or change the tint to give the deer brownish fur (like we're used to seeing).
I think I do OK using my camera's WB presets. For example, daylight gives me a color temp that I'm usually happy with if it's sunny outside. The part where I get confused is the tint. The preset always has zero tint, which works sometimes, but other times, it's too green (like if I'm under tree cover).
If you're shooting raw image files the image data remains unchanged regardless of the in-camera WB setting. LR simply reads the Temp and Tint values when WB is set to 'As Shot' and then applies them to the image. There's very little benefit to change the in-camera WB setting when shooting raw files.
I first set a custom WB using my Expodisc. I was expect this to be pretty close to technically correct. When imported into LR, temp = 5700 and tint = -4. Seems pretty reasonable (see first shot below).
The Expodisc is a simple diffuser that optically integrates the image in an attempt to set the camera's white balance reading to the "average" WB value. This is similar to how LR's Auto WB control functions, but not exactly the same. As wobertc explained if the image has a large amount of a predominant color (Green) that will "bias" the WB reading towards its complimentary color (Magenta). In short it only works if the image contains a "balance" of RGB color subject matter that is very close to neutral gray.
A better solution is to shoot your White Balance card under the common lighting conditions you use, such as Sunny, Cloudy, Tungsten, Flash, and Tree covered area (i.e. green filtered light). When shooting make sure the WB card is reasonably large (i.e. close) in the picture and that it is not over-exposed (i.e. in-camera clipped highlights indicator). The White Card is better for this purpose than the Gray card, but you can shoot both and compare their readings. Don't be surprised if the LR WB eyedropper readings are different than your 'As Shot' camera settings or LR's WB presets with the same names. You can save the different lighting condition WB readings from these test shots as Develop presets.
In addition to all of the above please make sure you calibrate your monitor on a regular basis using with an i1 or Spyder device. Using an uncalibrated or improperly calibrated monitor to set WB and color correction is an exercise in futility.
Thanks! The reason I like to set my WB in camera (even shooting raw) is that I find it produces a more pleasing result (to me). Sometimes, I don't even fiddle with it in LR. With AWB, each shot has a different WB, sometimes even under the exact same lighting.
I believe that Auto-WB in LR (and Auto-WB in camera!) will always be inconsistent, since any change to subject colors (under the same light) will influence the auto-WB result. Even cropping an image then applying Auto-WB can show a variation in WB result.
For consistency, if you shoot 'raw', (as above WB does not alter 'raw' image data) it is best to leave camera set to the sensors 'native' WB of 'sunny' and use a grey card (not the expodisc) in one frame allowing a batch correction with the WB picker tool in LR to correct all images taken in the same light.
After that it is all visual and subjective- to your desire!
Sounds like a plan, thanks. I've been experimenting with my grey card, but it seems inconsistent. Maybe it's not as neutral as it's supposed to be.
There are 'Grey' cards for Exposure, and 'Grey' cards for White Balance. They are not the same! In fact some Exposure Grey cards are definitely OFF-balance when used for WB.
So check your card type, do some more reading-
A good article can be found at this link-
When using the Expo Disc you point the camera at the light source to set the white balance, not the image. This is not the same as averaging the image to set the white balance.
I've been experimenting with my grey card, but it seems inconsistent. Maybe it's not as neutral as it's supposed to be.
The18% Gray card was originally created in the old "film"days for setting the camera's exposure and could also be used when printing for determining white balance. The White Balance card is a relatively new and created specifically for digital cameras. It has 90% (or higher) reflectance and provides a higher amplitude signal (i.e. less noise) in-camera. This makes for more accurate readings provided the camera exposure has been properly set to prevent clipping the white card image in-camera (i.e. highlight clipping).
You can also change the LR White Balance picker sample area in LR4 and later, which will provide more accurate readings. More here: Lightroom: Add options for larger sample sizes for White Balance Eyedropper Tool
I use a ColorChecker Passport to create custom camera profiles for normal lighting (Sunny Daylight, Tungsten, Flash). Develop presets are created for these camera profiles using just 'White Balance' and 'Calibration' for each lighting condition. My LR default Develop settings are set for Sunny Daylight.
That probably explains why I like the Expodisc and dislike using AWB.
Thanks! I've heard those Passports are nice. I might look into that someday.