Before I get started this is not designed to start a war. Nor is it designed to be a "mine is better than yours" discussion. Also I am not a professional tester, I do this for my own benefit and would encourage everyone to test their own sensors for their intended use rather than listen to me. I just thought this could be a good demonstration of the difference between theoretical and real world applications.
All photos were processed in Capture One. An LCC was applied and then everything was cropped and exported.
On forums around the world DXO is quoted often as the undisputed fact with regards to dynamic range. While this might be technically correct, I find it is rarely replicated in actual photography. My D3x had 13.7 stops according to DXO, however I don't recall ever taking a photo that captured that much information. So I was wondering how much of the reported 12.9 stops of my new P45+ I can actually use.
Here is my completely unscientific testing method, it is open to interpretation, errors, and is personally subjective.
You know, like photography
Step 1; Tape a test subject to a wall in an area with relatively even light. In this case my balcony (it's raining again here).
BTW I focused this using my Cambo loupe and GG. I am new at this and quite happy how it turned out. Taken with the Rodie 70mm.
Step 2; take a reading of the middle grey swatch (bottom left) and start there. Mine came out at 1/4s at ISO50 and f/8.
Then take a series of images above and below this reading. Crop out all the stuff you don't need and you end up with this;
Now here is the subjective part. I am looking for where the 18% grey and the white squares become indistinguishable for highlights, and the same with the black square for shadows. This will let me know what the DR of my sensor is for real world photography.
What about highlight and shadow recovery I hear you say. Well here they are;
2sec highlight +100
4sec highlight +100
1/250 shadow +25
1/500 shadow +100
So what do I see in all this.
Highlights I stop at 1sec, I can still see separation there so I am confident that my highlights won't blow. I could extend to 2sec (an extra stop) and use highlight recovery but I am uncomfortable with this as it leaves me no wiggle room at all. For the shadow end I stop at 1/125sec. I can pull detail out at 1/250 but it does introduce noise and once again leaves no wiggle room.
My target is large prints for sale, so I am after the best image quality I can get. If I was only printing small, or sharing on the web then I could go to the two extreme ends as the detail I lose, and the noise I introduce are inconsequential.
There is always NR software as well, however there is always a trade off with detail quality and this would be dependant on the subject photographed.
So for my intended use, the P45+ has a safe, usable 8 stops of DR. This means if I take a spot meter reading of the brightest part of my image, I can expect detail in all areas 8 stops below that. If the DR of the scene is greater than this I will need to use filters.
From my 12.9 stops of theoretical DR I can safely use 8, and this is in keeping with most cameras I have ever owned.