Well, as soon as we are gamma compensating our images we are rearranging the dynamic range codified into their data to fit in our display, print or visual (eyes) devices. Also when we edit these images using curves to locally increase bright in the shadows or make an overall contrast control we are also tone mapping.
I agree in that this is necessary to be able to enjoy all that DR in the final picture.
In what I disagree is that has become a general agreement that "HDR" means completely tone maped images obtained by using specific HDR purpose software focused on local contrast increase techniques which make them have a very particular and unnatural look. Maybe beautiful (this is always subjective) but unnatural like flyingpanter's sunset.
If I hadn't processed my previous image to lift the shadows, this is what you would get. But did my result above look unnatural? can it be called HDR without aynone complaining?
This is an interesting problem, Guillermo. It's true your interior room, after lifting the shadows, does not look unnatural and I think the reason is, you have not exploited the full dynamic range of the image. You've left some dark shadows in the corners, shadows which no doubt do not have any noise (or much noise). However, you can probably achieve a similar effect with a lower DR image by just clipping the shadows.
In a sense, the image is
unnatural, but in a way we expect (and accept) of a photograph.
Our eyes (pupils) have a remarkable ability to almost instantaneously adjust to differing lighting conditions as we shift our gaze from one part of a scene to another. Your HDR image of the room interior is esthetic. However, if we were actually there when you took the shots, we would notice much more detail in the shadows, specifically the lower left region.
The HDR process effectively allows the camera to more closely mimic the contraction and dilation of the eye's pupil by applying a more correct exposure to each major section of the scene we are photographing.
I tend to think the so-called unnatural effect of tone mapping is due to this presentation in one glance of a scene which the eye could not take in, in once glance in real life. To get the details in the shadows, we have to direct our gaze at the shadows. Our pupils dilate and we can usually see better detail than a single shot from any camera that also has to include the scene out of the window. However, when we direct our gaze at the shadows, we cannot simultaneously take in the scene through the window. An HDR image can, hence it can sometimes appear unnatural. Just a theory. I could be wrong, or at least over-simplifying.
One exciting feature of CS3 (or at least CS3E which I am now using) is the much improved auto-alignment feature in Merge to HDR. One can now merge hand-held shots, provided the longest exposure is not too slow for a sharp result.
It so happens that I often bracket exposures when I shoot high DR scenes, not for merging purposes if I don't have a tripod, but to ensure I have a shot which is very close to being 'exposed to the right'.
Here is one such shot, shooting against the light and therefore perhaps not particularly interesting. This is the 'normal' exposure which actually was a fairly correct ETTR. This is the one I would use to process this scene.
CS3E now enables me to use the other 2 shots, one stop under and one stop over, to create an HDR image, albeit with just a 2 stop increase in DR but with an effect I cannot get with just one exposure.
OK, it's unnatural. Too much local contrast, I think. It's easy to do and I didn't even (deliberately) apply any local contrast enhancement.