I think that D-range(manual setting ex.400%) is encouraged to a person who has more photographic knowledge like you,
and D-range(auto) is suitable for a person who wants to use the F200 easily.
Because it is the following reason.
When D-range is specified for user, it becomes under-exposure than D-range(auto) about the same scene,even if the same D-range numerical value is selected.
Well, D-Range auto can either choose DR100, DR200 or DR400. So the only difference here is when it chooses DR200 or DR100.
From what I have seen, these put your exposures at risk of blown highlights. DR400 protects them as much as is possible without pegging ISO at 200, a not so wonderful solution in all circumstances.
What DR400 also does is open shadows ... in other words, it flattens the tone curve at capture. This is often pleasing, but some people find it without punch. Each to his own, but I would rather not have my highlights blown and my shadows blocked ....
There is no underexposure involved with DR400 ... and adding positive compensation only makes the shadows even more open and the highlights again at risk.
On the other hand ... adding compensation when it is
useful , which means understanding what the meter will be doing, can be very useful no matter which tone curve you are using. Compensation should be used for the right reasons, and then the exposures will be perfect.
Someone who knows that thing can adjust the exposure compensation to the plus side a little in P-mode.
Why? You only do that when you know the meter will underexpose ... DR400 does not make the meter do that ... it only pulls in the highlights and uplifts the shadows a bit ...
Otherwise, the failure of the underexposure will increase.
DR modes only flatten tone curves and try to protect highlights a wee bit ... you still need compensation to handle the meter itself. For example, I find myself using -1/3ev or -2/3ev quite often ... even with DR400 engaged. Because the meter is still a meter ...
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