Quote "#1 Given that you could use CHDK raw/DNG instead, or generate a jpeg with whatever quality setting you want from the raw, I see little value in expending any effort on this. Especially considering how few CHDK cameras support native raw."
I agree, not a showstopper.
Quote "My feeling is that Canon discarded superfine because the small, high MP sensors are so noisy that the higher jpeg quality levels are basically just preserving more noise."
Noise is the first thing I studied in these cameras for potential CCD donors so you can count on my findings here. I demonstrated early on that the noise behavior in the SX110 and the S90 are at least 3Ev and 4Ev *lower* compared to the S50, so contrary to your assessment it makes all the sense to preserve real superfine. As obvious evidence, the SX110 certainly does preserve real superfine (8MB) despite a smaller and denser CCD, while the S90 and your D10 don't, and worse, we know now those two demote the qualities by 1 step:
SX110 superfine = S50 superfine ==>> real superfine
S90 #superfine# = D10 #superfine# = SX110 fine ==> real fine
S90 #fine# and D10 #fine# = real normal (if one follows the trend from the data in my last post)
Hence there must be another reason why Canon demoted qualities across-the-board for our two cameras. In my previous post I offered the availability of RAW in the S90 for the removal of #superfine#. But that does not explain the demotions in both our cameras. So one possibility for the demotions I thought of in our DIGIC IVs could be marketing ... people complained that they can't shoot fast enough with the PowerShots... that is, an improvement in speed-shooting because a small-size file to save // makes sense to me. And for the S90 #superfine# removal, I still think the reason is available RAW.
Quote "the value gets shuffled through too many pointers to easily follow."
Thank you for looking into your D10. I see it does look problematic, so too bad because it would really help. I know it doesn't have luster and pizazz, but personally I would put this solution into the basic operational parameter category rather than of course the fancy feature category.
Quote "If you really want every last bit of noise, use raw."
I demonstrated noise cannot be the reason for compression quality manipulation by Canon. In fact this is especially true in the S90 as it has the lowest noise of all the cameras I tested: S50, S70, S90 and SX110. So like the SX110, the S90 (and your D10) should have the opposite: "a very high superfine," that produces an 8MB file. As I explained in my previous post, using RAW for 99% of the shots is an operational kludge when trying to focus on science, when fast-performing excellent JPEGs will suffice. That's why control over the quality parameter would be very very useful for scientific applications of these high-end CCDs and signal processors.
