Why the color is different in two pictures in similar conditions and setting?

Question

I have two pictures taken today with my Nikon ZFC MILC + Nikkor Z 50mm 1.8S lens. The photos were shot in the morning at around 7:30, it was cloudy and raining slightly (you can see the water drops on the leaves). They were shot within two minutes and there were no changes in light conditions. They were taken from the same place and the target is the same tree. The second picture target is slightly to the right and about 4 feet farther.

Why isn't the first picture green like the second one?

EDIT ADD: I have three pictures of the first target and three for the second farther target. They have the similar color as in the attached pictures.

File:           DSC_1188.JPG,
Date Created:   17-05-2024 07:31:07,
Date Modified:  17-05-2024 07:31:07,
File Size:      7.63 MB,
Image Size:     L (5568 x 3712), DX,
Image Quality:  Jpeg Fine (8-bit),
Device:         Nikon Z fc,
Lens:           NIKKOR Z 50mm f/1.8 S,
Focal Length:   50mm,
Focus Mode:     AF-A,
AF-Area Mode:   Wide-area AF (S),
Aperture:       f/2,
Shutter Speed:  1/800s (Auto),
Exposure Mode:  Aperture Priority,
Exposure Comp.: 0EV,
Metering:       Matrix,
ISO Sensitivity:ISO 200,
White Balance:  Auto1, 0, 0 (7750K),
Color Space:    sRGB.

File:           DSC_1189.JPG,
Date Created:   17-05-2024 07:32:47,
Date Modified:  17-05-2024 07:32:47,
File Size:      8.70 MB,
Image Size:     L (5568 x 3712), DX,
Image Quality:  Jpeg Fine (8-bit),
Device:         Nikon Z fc,
Lens:           NIKKOR Z 50mm f/1.8 S,
Focal Length:   50mm,
Focus Mode:     AF-A,
AF-Area Mode:   Wide-area AF (S),
Aperture:       f/2,
Shutter Speed:  1/400s (Auto),
Exposure Mode:  Aperture Priority,
Exposure Comp.: 0EV,
Metering:       Matrix,
ISO Sensitivity:ISO 200,
White Balance:  Auto1, 0, 0 (4650K),
Color Space:    sRGB.

Answer 1

The camera's metering system and auto white balance system are basically a database of many shooting scenarios, and the camera tries to "guess" what you are shooting and how you want it to appear. If you move the camera, and, for example, there is more sky in one photo than another, or more dark areas, or more bright areas, or more green than blue, or more blue than green, etc, etc, then the camera may decide that you want a different look.

If you want precise control of the colour captured by the camera in these situations, you should look into how to measure and set a custom white balance in your camera.

Another option is to shoot in Raw format instead of JPEG, and adjust the white balance afterwards, on the computer. If things get really critical, it helps to shoot with a known colour reference in the scene – something like a ColorChecker Passport. But you can get very good results using other options like a small WhiBal card, which is more subtle, more portable, cheaper and quicker maybe.

Answer 2

To give a somewhat practical answer... I notice there is what looks like a wall or something in the foreground (quite out of focus) in the "more correct" picture. This wall appears to be white, which suggests the camera was able to use it as a white-balance reference, whereas the first had no such reference and the camera had to make a "best guess". Other Answers explain how white balance caused the problem; I thought I'd take a shot at why it might have happened.

I would be really interested to see the unadjusted (i.e. no color correction / white balance and minimal levels/contrast correction) raws side by side; probably they are a lot less different. On which note, I strongly recommend, if you can afford the storage, to always, always shoot raw. A raw has a greater dynamic range, and if the camera does something like horribly botching the white balance, post-processing from the raw will give you a result as good as (or better than!) if the camera had gotten it right, whereas trying to fix the already-processed image is a lossy process. In general, you can do better processing offline than what the camera does in-body. (Arguably you can even get better debayering results from offline processing, particularly as you have the ability to change algorithms depending on what you're shooting.)

Answer 3

Why the color is different in two pictures in similar conditions and setting?

Because you told the camera to use Auto White Balance and then, in the "eyes" of the camera's logic system, presented two different conditions/settings.

The second image has a area area to the right that the camera interpreted to be what should be neutral white, so it adjusted the WB to make that large area with the same light color close to neutral white.

The first image has nothing in the frame that looks anything like a neutral white/gray object in it, so the camera used a different method to determine WB in that image.

The two different conditions in the frame which led to two different methods used by the camera to automatically determine WB led to two different WB results.

White Balance is needed because not all light sources emit the same combinations of wavelengths of visible light in the same relative amounts. Without adjusting for WB, the same objects would show up under various different light sources as different colors. Our eye/brain system is usually very good at adjusting for the differences in light sources so we perceive the same object is the same color under most light sources, particularly those that are natural or mimic natural light sources such as the sun, a burning bonfire, a coal oil lantern, or a tungsten light bulb. Cameras, on the other hand, aren't as adaptable as our eye/brain vison system is, though they keep getting better and better all the time.

Related:
What factors affect a camera's ability to accurately perceive color?
How do I find the right white balance value to set in my camera?
This comprehensive answer to What exactly is white balance?
What is white balance in a camera? When and where should I use WB?

Answer 4

As we compose each picture we take, the camera’s logic (automatic mode) chooses the shutter speed and aperture setting based on its built-in logic. The results, most of the time, will be very satisfying. Sometimes this camera logic fails, and the outcome is deemed substandard. Note the camera measured the color temperature of the vista as 7750K for the first and 4650K for the second.

Now, photo scientist measures the ambient color of light playing on a vista using a system called “color temperature”.

Note: Your first picture is assigned 7750K and your second picture assigned 4650K by your camera. Why is this?

The logic of the camera averages the colors of the vista being photographed. The method used varies from camera to camera, nevertheless, in auto mode this value is called an integrated color balance. This value will change based on the distribution of colored objects in the composition. Note one image shows more blue-sky than the other.

The color balance data is used by the built-in computer logic of the camera to apply a correction factor that will hopefully make the resulting image more “faithful”.

Most of the time this scheme works well. When it fails, we old photofinishers have coined the words “Subject Failure” to classify this error.

Study your camera manual for workarounds that thwart this failure.