Doug Kerr said:
Yes, Dear Santa,
It is impossible for a person wishing to get optimal exposure to do so using the tools in the camera, as the camera histograms are based on the JPEG parameters, which have little to do with the RAW capture, which is where exposure matters to the RAW shooter. Most people under-expose their image, resulting in needless data, because of this JPEG-level feedback. A RAW RGB histogram with very clear clipping indication (not like the nearly invisible thin dotted line for maxvalue on my 20D's JPEG histogram), complete with flashing of clipped highlights on the JPEG review image, in color, at least as an option (IOW, alternating black with red, green, blue, magenta, cyan, yellow, or white depending on which color channels clip).
None of your 1/3-stop "in-between" ISOs seem to be real; they are either an extra stage of low-gain amplification before digitization, or mathematical exposure compensation. Please give an option in the camera to turn them off, if they're going to be EC controls, under the hood. ANyone who knows what they're doing probably won't use them, once they realize what they are, and they are a nuisance to dial through.
Please implement auto-ISO, at least for manual exposure mode in future models. An EC control would be necessary, just like it is now for AE modes. When a person has elected to turn off any non-optimized ISOs as mentioned above, resort to a list of user preferences for obtaining EC for full exposure, such as:
1. Av +1/3 stop
2. Tv +1/3 stop
3. 0
4. 0
5. Av +1/3 stop
6. Tv +1/3 stop
7. Tv +1/3 stop
8. Tv +1/3 stop
The first two would be used to adjust the relative exposure granularity at all ISOs except the highest. The rest are a list of what to do for failed exposure at the highest ISO; in this case, I want to under-expose by 2/3 stop before I start opening the lens and lengthening the exposure.
Or, better yet, just allow the user to supply user-program modes that are lists of Tv, Av, and ISO values for metered EV values. Again, an EC control would be needed here, to adjust for scene key and contrast, as we can do now in AE modes. It can offset the EV value before consulting the list.
Frankly, the current modes of exposure are archaic and film-based. It takes too much time away from following your subject, focus, and composition to try to maximize everything on the fly. Why can't I have a way of shooting that doesn't stop the lens down too far, but won't result in blurred images in low light, like Av-pri does now?
Please stop doing math on RAW data after it is digitized. It is more valueable as-is, than mathematically manipulated to meet a standard. Who cares if the image is 0.05 stops under-exposed? No need to posterize the data, and clip away highlghts, however lightly, to compensate.