on manual focus it doesn't tell you which way to turn the ring, unlike Nikons
Can you clarify for those of us that shoot Canon what you mean by this? Manual focus is exactly that, manual. If you want it to tell you which way to turn the ring, rather than by reading the distance scale or by trial and error, why would you not just use auto-focus and have it do the whole job for you quicker than you can?
Sometimes manual focus is better, or obligatory. Auto focus does not always do it better than the user.
Then it can be useful to have the camera tell you which way.
An example would be where there's movement and you don't want the risk of the camera losing it and hunting for a time.
Nikon bodies with MF lenses, still have the body telling you which way. It's particularly useful with macro assemblies, Zeiss lenses or whatever.
Distance scale? You want me to stop to look at a distance scale to see what it says, measure the distance and work out which way the lens has to be turned? Easier to prod the ring and try again.
The STM lenses I've been quoting, don't have a distance scale, & I don't miss it. Others I have, do.
There is a custom function setting for whether AF lock is a prerequisite for shutter release.
ERRM - no there isn't. Lean towards, not require release. Are your bodies different?
If that's what happens when you first engage AF, you have something amiss. It should always try, unless you have a lens that is too slow for it to work, or it's really dark, or the lens is malfunctioning. Once the camera has tried and failed, there is a custom function setting for whether or not it keeps trying, or it gives up and stops.
It's doing what Canon make it do by design - nothing.
It's decided it can't focus, it continues to decide that it can't focus, then it decides again that it can't focus - - so it keeps doing nothing.
As you say, it gives up.
Nikons appear to think "I can't focus, so I'll fire the shutter as you requested then go hunting" or something. Canon does nothing, in single or AI modes..
How easy was it to take your 50mm STM apart? It makes sense to get one of those.
The 24 looks interesting too...
I have some Nikon & Canon bodies, I may try a Sony - I'm not pro or anti by prejudice. There are pros and cons, of course the abilities vary, but the Canons have more little annoyances which seem unnecessary. Like if I'm reviewing during my 2 second review period, why doesn't the Expand button work without me having to press the Review button? As an observation, things more often tend to not work on the Canon if something else isn't in a particular mode, where Nikons don't care, things just work.
Most of them one just learns to live with, but hey.
In my local photo club there are Nikon, Canon and Fuji fanatics. Good grief if we didn't have religions we'd have camera wars!
Back at 6D versus 80D, I was reflecting on the virtues of a wide DR.
Taking snaps in a cathedral (stained glass windows + interior), then just ordinary shots where there's a sky with featured white clouds, more would have been useful. The best sensors woulod have given me ~1 stop more. Enough to make a big difference? Not dramatically, I think.