1. E.V. In all my Nikon cameras, in A mode (Aperture), when changing an Iso value, the speed value changes ton maintain E.V. to 0. That's it, so easily
In the S25U Pro or Expert Raw modes, changing an Iso value moves Auto to Manual, but if Speed stays in Auto mode, E.V. indicator still shows E.V. 0, but in reality, it needs to be adjusted to 0 So, turning Speed in Manual mode really shows E.V. value, and adjusting Speed allows to adjust E.V. to 0 balance
This is similar to the full Manual mode of a Nikon camera, who needs extra Care to adjust settings to match E.V. to 0
Is there in the S25U Pro or Expert Raw modes a way to change Iso value and obtain a related Speed adjustment to maintain a true neutral E.V. of 0 ?
2. A.E In Pro and Expert Raw modes, touching the screen allows to separate the AF point of the AE point, and place them in a selected zone of the screen But this works only if all settings are in Auto mode. When changing one parameter value (i.e the Iso), the AE point disappears
Is there a way in the S25U to still have AE point where placed manually when editing Iso or Speed ?
Point 1 is probably because there is no aperture iris in the S25U. In F mode (aperture priority) the claimed aperture appears to be provided by the ND filter model. For example, aperture changes do not change depth of field. Then, if you enable the ND filter instead of F (aperture priority) mode and adjust the ND filter level using the drop list rather than the slider you will notice that shutter speed and ISO are manual and EV can't be adjusted but the effective EV is shown.
Taking it from the other perspective, only ISO and shutter speed can be adjusted then aperture and ND filter are both just "simulated". I'd say its two Expert Raw bugs that when you use a random manual ISO and shutter speed is Auto then:
1. The shutter speed doesn't change as you adjust ISO; and 2. The EV value doesn't change while adjusting ISO to show the effective exposure compensation
You can view it by simply switching the shutter speed also to manual at the same time as using a manual ISO, now the EV value is automatically changed to show the exposure compensation. This is probably the best workaround, if deliberately using a manual ISO for one of the typical reasons, it is also wise to use manual shutter speed and adjust it without changing the preferred ISO until the EV value shows the preferred exposure compensation. The EV level should be the number of f/stops.
IOW, yes, spinning ISO up and down manually with shutter speed on Auto doesn't cause the shutter speed to change from the last one set and doesn't report the effective EV value so it's left with unknown exposure compensation.
OTOH, if you leave ISO on Auto and manually adjust shutter speed up and down instead, the ISO is automtically adjusted while in-range for the frame AND, you can manualy set a preferred EV and as you move it up and down only ISO is adjusted, since shutter speed is already fixed manual. That's probably the best way to deal with it. Set shutter speed on Manual and ISO on Auto. Set a preferred EV then adjust the shutter speed until the automatically chosen ISO is the one you want to use.
Regarding your question 2., the AF and AE points can be split if you use the workaround of using Auto ISO and Manual shutter speed. Set your preferred EV level and touching the screen works to set and split the AF and AE positions. Now, manually adjust shutter speed up/down until the displayed ISO is what you want.
The range of ISO isn't large, though the range of shutter speeds is huge so you can easily exceed the ISO range using the above but with a little bit of familiarity it's possible to effectively select a preferred ISO even when ISO is set to Auto by using a Manual shutter speed and adjusting it up/down to get your preferred ISO (automatically). Obviosuly not an easy solution in variable light such as outdoors with moving cloud or a scene of people wearing a variety of clothes moving through the scene, etc.
It's a pretty crappy bug that Auto shutter speed isn't maintained when using manual ISO since it's simply the inverse of the computed Auto ISO when using Manual shutter speed. Worth reporting to Samsung (camera app generally) or also to Samsung via the Expert Raw project in the App Store.
