Expose To The Right. Often cited as a desirable exposure mode that camera companies willfully refuse to implement because they are dumb and don't listen to photographers. Let us set aside the fact that ETTR is a dumb idea.
Let's actually consider this. What would it take?
What is it? Well, usually the pundit will say that the camera should select the greatest exposure which will blow out at most some percentage (which translates trivially into some number) of pixels. Question: Before or after Bayer de-mosaic? Question: What do the error bars looks like? If the camera should blow no more than 10,000 pixels, does that mean plus or minus 10 pixels? Plus or minus 1000 pixels? Or do we insist on exactly 10,000 pixels?
How will the camera do this? Well, it has to take one or more exposures, and count blown pixels. If too many pixels are blown out, then the camera has to guess how much to reduce the exposure by. It can't calculate it, it has to guess, and try. The pixels are blown, we don't know by how much, after all. The built-in meter will probably help.
Let's suppose that the camera has a worst case of 5 guesses to get close enough to meet the criteria. At a 60 fps frame rate (let's assume we can retask some of the video logic for this process), we're talking almost 1/10 of a second of lag here just to calculate the exposure. Oops. Note: the more precisely we want to manage the number of blown pixels, the more test exposures we're going to need, with consequences that flow through the system.
How will we do these calculations? We're not going to chew through 5 frames of 24 megapixels each with some dippy little micro-controller, it's got to be the image processing engine. Question: Can we program the engine to count blown pixels? Question: Is there a way to get the count of blown pixels out of the image processing engine into the exposure control logic? Note: If either answer is no then we need to be looking at some new features in the next generation image processing chip, and ETTR exposure mode is impossible in this generation.
So now we're processing frames. We can reduce the shutter lag by doing rolling exposure estimation, but now we're running the image processing engine constantly, draining the batteries at a brisk clip. Question: How can we best architect this to give acceptable shutter lag performance in most cases, without excessively compromising battery life?.
So our best case development plan here involves several design meetings sorting out exactly what the feature actually does, how it works, and how to balance the various compromises. All compromises will produce noticeable shutter lag at least some of the time, and will reduce battery life by some degree. Let us assume that we do not need to build a new chip.
Next up is writing software for both the main processor (menus, settings and so on), some software for actually setting exposure, some software for the image processing engine to do the heavy lifting.
Then there's the manuals and the QA and the manufacturing and the translations and the reviews and all that stuff.
I am not seeing this as less than 1 month of full-time-equivalent staff time, assuming it's even doable inside the current camera architecture. A week from this guy, a day there from her, a couple days over there. A month is a light estimate.
An FTE (full-time-equivalent) that this level runs a fully loaded cost of something like $150,000 to $300,000 a year (salary, benefits, rent on office space, janitorial services, depreciation on computers and furniture, insurance, etc) so a month is going to run you $12,500 to $25,000, roughly. You need to recover that in profits, and since you're not running a commune here you need a multiplier on that, so you need to see a reasonable potential for something like $40,000 to $100,000 in profits. Assuming that you're looking at gross margins of something like 30%, you need to see $120,000 to $300,000 in sales (to the dealers, call it $150,000 to $350,000 retail). If it takes 2 months instead of 1, or you need to redo a chip, you could be getting into "a million bucks, retail" territory, which is 100s of bodies.
Now, when you do release this thing, the people who clamored for it will, you can be assured, complain loudly about the shutter lag and battery life issues introduced by ETTR, and urge their readers to wait "for the second generation when they will have finally sorted out these critical issues, we (sigh) hope." So your actual increased revenue will be somewhere in the area of $0, plus or minus.
I dunno about you but I cannot for the life of me see why camera companies aren't rolling out this simple, obvious, feature.