A number of us LL'ers have the Canon G9 and are attempting to deal with the noise at the higher ISOs. I've written about one set of experiments on my blog,
http://lightdescription.blogspot.com, but there remains much to be learned. Why not make a joint effort?
Please don't jump in with "... sensor too small", "camera no good", "get the exposure correct", "get a Fuji", etc., etc. My intent is to generate dialog from meaningful experiments and to share techniques and best practices for processing RAW files specifically from the Canon G9.
Certainly there are more than one set of answers but, at the same time, some of this processing can be done with Photoshop Actions (preferably while I'm sleeping).
At this point, summarizing from my blog, I think ISO400 from G9 RAW can be very useable for up to 8x10 prints. ISO 800 is iffy; 1600 is probably not useable for 8x10 prints -- but I am hoping!
I use Neat Image. I don't know if it is better or worse than other noise reduction software but I have it and have used it for several years. I've made the Neat Image profiles from the Neat Image calibration prints and noted that the profiles are different according to how the RAW image is processed in ACR. The calibration print profiles are also different from the auto-profile for a specific RAW image file. (I've not posted my Neat Images files because ACR for the G9 RAW is still a Beta.)
It seems to me that noise reduction (meaning Neat Image for me) is best done immediately after opening the RAW file. I've found that, as expected, the Neat Image profile generated from the Neat Image calibration prints varies according to how the RAW image is processed in ACR. Most significantly, assuming "correct" exposure, a Neat Image profile varies with ACR noise reduction, if any, and ACR sharpening.
It's easy to say "don't do ACR noise reduction or sharpening" and that may be the conclusion when all is said and done. However, my sense of it all is that there must be some optimum with respect to ACR noise reduction and sharpening. That is, the ACR noise reduction is probably not based on exactly the same algorithm and settings as, say, Neat Image. Therefore, there may be some optimum combination. Same reasoning with respect to ACR sharpening and PK Sharpener (my choice).
At this point in time, my post processing of G9 ISO 800 RAW files uses
ACR Detail page settings: 50, 0.5, 20, 80, 0, 100 (slight change from my blog)
Neat Image: noise profile from Neat Image ISO calibration print, half strength
PK Sharpen: capture sharpen, high resolution camera, medium or narrow to taste
It now seems to me that the luminence setting in ACR tends to reduce detail (not apparent in Neat Image calibration prints) and generates "plastic blotches" (to use a technical term). Therefore, I've decided to set luminence noise reduction in ACR at nearly zero.
So, how about some other techniques and settings?