This is an excellent post.
It's hard to argue against manual exposure mode, especially when the subject is such that you are able to take your time.
Having said that, I usually shoot in aperture priority mode if I'm not on a tripod for relatively still subjects. Or in shutter priority mode for rapidly moving subjects.
The reason is that if you understand how your camera makes exposure decisions, you can potentially set it up to automatically make the decisions you would make if you were in manual mode.
For Nikons, there is a submenu in the photo shooting menu for ISO sensitivity settings (and this submenu can be added to your My Menu). The settings in this submenu dictate how the camera will respond regarding exposure settings if you are shooting in aperture priority or shutter priority. You can set things like maximum ISO and minimum shutter speed.
The exposure algorithms for Nikons seem to go something like this:
In aperture priority mode, there are break points where either shutter speed is lowered or ISO is increased to achieve what the camera thinks is a proper exposure at the given aperture. This is the behavior in low light. In strong light, the camera prioritizes a lower ISO over a faster shutter speed.
In shutter priority mode, it is more straightforward: even without limits the camera chooses the most open aperture to achieve what it considers a proper exposure and only then increases the ISO if needed. In strong light it will go to base ISO and then stop down as needed.
The ISO sensitivity menu can modify this behavior, which tends to be most relevant in aperture priority mode. You can set the minimum shutter speed or highest ISO to force the camera to aim for a minimum shutter speed, increase the ISO once that shutter speed is hit, and then only lower the shutter speed if the ISO limit is reached.
In my case, I have the maximum ISO set to 1600 (which in my experience is the highest ISO I find acceptable on my D850 or Z7). I have the minimum shutter speed set to 1/125th sec (which in my experience is the slowest shutter speed that doesn't blur subject movement when my son is relatively still).
These settings mean that I can pick up my camera and shoot my son indoors with a good chance at sharp pics. If the light is poor, I can get him at 1/125th sec to freeze motion with the possible downside that the ISO will creep up to 1600. This is exactly the choice I would make in manual exposure mode. If the light is better, the ISO will come down. Again, exactly the choice I would make in manual exposure mode.
In shutter priority mode, the camera is also mirroring what I would often choose. In lowish light (say a bouncy house) I would want to shoot wide open with the lowest ISO that the exposure allows. There are exceptions where I might want to stop down to increase DOF at the expense of ISO and in those cases I'm **** out of luck in shutter priority mode. But that is what manual mode is for
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I think aperture priority and shutter priority modes are fine as long as you understand how your camera is making exposure decisions in those modes and have set up your camera to make the choices you would make in manual mode. For subjects where you don't have time to fiddle with the exposure triad, these modes can be extremely helpful/useful.