Hei, (new 17.12.2019 firmware installed)
The snapshot modes F/8 2m and F/5.6 5m are useful but then you have to accept some limitations.
The camera can remember the snapshot setting after off-on. But if you rotate the mode dial when power is on then the snapshot will be off.
There are 3 AUTO ISO presets having 3 PARAMETERS: "DEFAULT SENSITIVITY" "MIN SHUTTER SPEED" "MAX SENSITIVITY"
In A-Mode works like this: "DEFAULT SENSITIVITY" e.g. ISO200 used as long as possible with shutter speeds 1/16000 - "MIN SHUTTER SPEED" e.g. 1/60 s After that in darker the ISO will be increased from 200 to "MAX SENSITIVITY" e.g. ISO6400 while the shutter speeds stays in 1/60. If it becomes still darker the shutter speeds 1/60 ... 30s will be used with ISO6400. I have not tested what happens if there is darker than ISO6400 & 30s perhaps still larger ISOs will be used.
Snapshot in modes:
A-mode (and P-mode): front aperture dial does nothing, use back dial to change exposure correction -5 .... +5 EV = 10 EV. You can set ISO or use Auto ISO,
camera can change shutter speed from range 1/16000 & ISO200 to 30 s & ISO6400 =23 EV range (Auto ISO on) or 18 EV range (ISO selected)
easy job for the camera in varying lightning conditions to give selected exposure correction in range -5 .... +5 EV = 10 EV
safe and easy mode for user,
S-mode: use front aperture dial to change shutter speed 1/16000-30s = 18 EV, use back dial to change exposure correction -5 .... +5 EV = 10 EV. Total range for user = 28 EV!
the camera can change only ISO (if Auto ISO on, max Auto ISO range 6400-200 = 5 EV) and if the user sets fixed ISO other than auto, then the camera is in manual mode (shutter, aperture and ISO set by the user)!
difficult job for the camera to avoid under or over exposure if the user is not careful: check the result and keep eye on histogram
This works well in other modes also though manual says: "Enable exposure preview in manual exposure mode" (the preview is good)
M-mode: front aperture dial does nothing, use back dial to change shutter speed 1/16000-30s = 18 EV and also the same dial will change exposure correction with the AUTO ISO rules.
Regards, Raimo
PS
I don't use snapfocus. I use A-mode and manual focus + back button focus. I have dedicated the Fn button above Q-button to Instant focus. It works almost like snapfocus (keeps focus) but it let me do more. When I press the button the camera will focus where I want and it keeps the focus and keeps it if I change mode when camera on, turn off on. In addition I can change the exposure correction, F-value to control dof and use manual focus ring if needed e.g. to be sure the focus is in infinity. In my setup the focus ring of the lens works as manual focus ring (very slow response in close "makro" distances) but in snapfocus mode the ring is for digital zoom 28(no zoom)-35-50 mm.