I'll try to be as constructive as I can.
I've put a disclaimer somewhere in Lu-La about that topic.
OP's question: Why is so that persons with considerable experience have quite different opinion on the issue?
IMO, simply because all these apparently contradictory statements have a part of truth.
I don't like at all those "in between lines" sarcastic comments on Mark that are diseminated each time this topic appears.
Putting constantly an etiquette on someone's under the pretext that he was wrong in an article is not a practise I enjoy reading,
very teenager behaviour. So as we are in between men I guess, it would be nice if ones for a while we could bring that debate ahead
without pointing Mark's "heresy". Because he might not be as wrong as we think and let me explain this point.
The DxO are NOT trustable on a real basis. Until you can not recognise that fact and take the DxO measurements as only an indication of a data,
you will not be able to accept the subjectivity and apparent contradictions.
So you are trying to understand something that seems absurd and questions will emerge over and over again without being answered
because the reference you are taking is not enough.
DxO is very similar to horsepower. They measure rigurously, in a scientific way, a value called DR.
A car can have 200 horsepowers, a camera can have 11 stops DR. This is a value, based on a sort of standard of measurement.
DxO is not even a worldwide standard like for example temperature measurement. DxO is french people who decided to do some testings following a specific
methodology. Just an observation. But anyway, let's say they are trustable. They are trustable only to bring some datas that have been measured in a specific
Now, we all know that horsepower is just one element of a car's performance. There are many other parameters that can make the differences.
In those, the conditions play an important role also. DxO is not trustable, not because they are bad, but because it simply can not explains
where and when those DR differences happen. They only give a usefull indication exactly like horsepower does. But the field is another story and can contradict these facts.
If you follow the formula one championship, maybe the most tech and demanding sport, you will see that those facts happen all the time: measurements that are not
trustable in this or that circuit, who are alterated by temperature, humidity etc...
If you relly on DxO to understand why those things happen, it is like you would relly on horsepower as a fix data to understand a fact, and of course, all that falls appart.
If the most tech demanding sport is actually unable to explain the differences by measurements, I doubt a little french comitee doing testing can give you any clew.
Then, there is another factor wich is the capture and the post production.
I think that the pictures in this thread are showing an impressive DR. Tipically the situation where you would prefer having a P65 than any other gear.
6 stops? No, of course not.
I don't know the D3x capability so I won't speak about it.
But then, there is the post-production task. What's called the room. The real information contained and the recuperation capacity.
Should we call that DR ? maybe that's the clew.
But in this area, the differences are indeed big.
In controled light, I doubt that the DR differences are significatives. But in others situations, they could be.
So all those concepts are subjectives, each case being a case in itself and maybe we should also consider the use of the 2 letters DR.