There’s some things I know enough about to know I’m an idiot.
And white balance is one of them. If I say the other one is calculating bounced flash distance, then you might know where I’m heading.
If I’m bouncing flash off a ceiling, I might be able to guess that the flash distance to subject is about 8 ft, then I could use the GN of the flash at the set zoom angle to calculate the exact amount of manual flash I need for the aperture I’ve set (then recalculate as I move, my subject moves or I change aperture). But that’s tons of information to compute! If I use ETTL, the flash does it in less than the blink of an eye, and brilliantly. I might want to add a little FEC, but compared to the work done by the camera, I’m fiddling round the edges.
Yes, let's not over-complicate a simple process.
ETTL is the obvious tool, for most situations, it will sometimes get it "right", it will nearly always be good enough and it will never be totally wrong. For pretty much all "quick" shots, where there's little time to experiment, it's a no-brainer. For something like still-life shots, where there are no time pressures, we can always set the flash power manually and should, usually, get better results - but casual viewers are unlikely to see much if any difference.
Likewise white balance. I could buy a colorimeter, an expensive piece of kit that will give me an exact colour temperature I could set in camera, I could use a colorchecker passport, take a test shot and set a WB in camera, or slightly more lazy, use that test shot to correct the WB in post. I could use a white card to take a reading off, not quite as accurate but also works.
Or I could use AWB, then check the temp on screen whilst processing and batch process my images in seconds for free and stress free.
Some of the automation in our cameras allows us to do really complicated things simply. And calculating colour temperature is definitely on that list for me.
When I did this for a living I used a colour temperature meter routinely, because when clients are paying a lot of money for the shots they need to be right, not somewhere near, but the world has changed, and although I still have one somewhere, I haven't seen it for years because it's no longer relevant as far as I'm concerned. Originally of course, I shot everything on film, if the colours were wrong there was nothing that could be done about it, and even when the trannies were scanned, allowing PP work, the software wasn't that good and computers were too slow to facilitate effective colour correction. When digital took over things got a bit easier but it was still essential to get the colours right, and the way that I did it was to filter individual lights with CC gels, to match them.
Back then, one of the problems was that colour temperature varied according to the power setting of the flash, pre IGBT. There are still variations with IGBT but they are far less, and the cheaper flash heads were pretty terrible in terms of consistency, and the bold claims made by most manufacturers were simply lies, they knew perfectly well that hardly any of their customers had the skills, equipment or interest to check for themselves. There are still good reasons to stick to a single make of flash, and to not mix IGBT with non-IGBT, and then there's the massive colour temperature variations caused by different modifiers, e.g. softboxes that have yellowed, and despite wild claims about CRI, continuous lighting causes problems too, although many of the LED lights aren't too bad today.
Add in the complication that my bounced flash on the subject is maybe not the same colour temp as whatever is lighting the rest of the scene, and we then get to the question of ‘what is a correct white balance’.
Good point, and especially when people create "fill" by using a longer shutter speed to include whatever ambient light happens to be present.
"Correct" white balance is neutral, but I once took a portrait shot and changed the colour temperature in PP, starting with "correct" and ending with 500K too warm, a massive difference, but everyone who saw those shots preferred the most warm version
And there's another factor too - everything used to be presented in print form, but today very few shots are printed and the vast majority are just viewed on a computer or phone. I have 3 monitors, 2 are calibrated and so should be "right", one is just used for documents and is a cheapie that isn't calibrated. If I look at a shot on both a calibrated and on the non-calibrated monitor then the differences are dramatic, but most people don't have a calibrated monitor, so most of the effort that can go into getting correct white balance is just wasted.
