Allow me to explain the question which might seem slightly vague.
One particular use case where i generally face this question is when i am shooting something during nighttime, dark conditions. In these cases, when the scene is too dark for autofocus to work properly, i generally go to another area where i have some other well lit object at a similar distance and then use half shutter press to focus on it.
Now, since i have the focus set to my preference , i go back to my OG subject and then hold the AE/AL button (it is set to AE/AF lock) and take a picture. Now, i may not like the picture, so i might change some setting in the camera. Do i now have to go back to the well lit object to set focus again, or can i just repeat the same thing after changing settings, and just take a second photo while holding the AE/AL button again ?
Now i know, "changing settings" is too broad a term. There are a hundred settings that can be changed. So, i am trying to divide them in my mind, into different levels of settings .
Level 1 : Changing image quallity ( norm, fine, basic) , size , picture mode ( standard, vivid etc.)
Level 2 : Changing PSAM modes, changing shutter speed, ISO , exposure comp etc.
Level 3 : Everything else, more indepth settings, in the camera shooting menu etc.
Level X : changing aperture ( i feel this HAS to be changing the focus, so i put it in separate level, correct me if i am wrong )
Now, i understand these levels are just imaginary, there might be different things in different levels that do need me to autofocus again, and some that do not. But is there any standard rules that most cameras follow regarding which settings can be changed without affecting the focus and which will need me to re-autofocus again ?
Also, one of the suggestions in the comments about turning off autofocus completely, makes good sense. So, if i autofocus once, and then turn off Autofocus, can i be assured that as long as i do not mess with any focus setting ( e.g. AF-C, AF-S etc. ) or manual focus ring, the focus will stay where it was ?
Which settings affect the focus distance and will need me to focus again, and which can i just change and click a picture without having to focus again ?
I tried looking at the manual , but what keyword should i be searching for in the manual ?
I use a NIKON D5600 with a Nikon AF-P DX nikkor 18-55mm 3.5:5.6G VR lens