Very new to photography, using a EF-S 24mm f/2.8 STM lens on a T6 and a 40D. Doing my best to explain what my problem is.
I'm trying to use Manual Mode as much as possible, so I had the not-so-smart idea to use Auto Mode for a sample (first) picture of every set and get similar images after making F number, ISO, exposure and white balance variations. The results have not been what I expected mostly because when I switch to Manual Mode and recreate the settings of a picture taken in Auto Mode the end picture is usually very different.
The pictures at the top of each link were taken on Auto Mode. This is how I remember seeing the world.
The bottom pictures were taken in Manual Mode with more or less the same settings (WB is cloudy since it was an overcast day). I don't recall April/May days being yellow in Canada -only during July and August. The difference is not so dramatic on sunny days between 10h and 15h, but very noticeable when there are clouds.
What am I doing wrong?
How can I manually recreate pictures taken on automatic?
The exposure (ISO, Aperture, shutter speed) looks okay. The problem is AWB doesn't match the white balance you chose (or vice versa).
Try taking a picture with each available WB mode that's not obviously wacky (aquarium?) to figure out which one most closely matches what the camera chose. You'll have to double check every time the lighting changes. Often what the camera uses isn't what you'd think based on the name. (You chose cloudy because it was cloudy, but AWB chose shade. Why?)
You can also use custom white balance. Many would consider this "best" practice, but likely won't match AWB, if that's what you're after.
AWB is not restricted from choosing one of the pre-defined presets - it can and will pick values anywhere along the spectrum, almost always between the presets somewhere. You will rarely find an AWB shot that picked exactly one of the presets.
I suspect it depends on the camera make and model, but recently got rid of my Canon DSLR, so cannot test.