Further to my other message on the subject of the tests with and without HTP, I did get back downtown this morning to re-shoot images similar to yesterday's of the same group of buildings - these are tall black office towers - Torontonians will know them - the TD Centre. I had two incidents of being stopped by security asking if I was a professional photographer and what I would be doing with the pictures. The second one explained he stopped me because he noticed the camera looked kind of professional. So I told him nah - it's just an expensive P&S that allows some adjustments . He didn't buy that, wanted to know what I was doing with it, so I told him I was testing the camera for digital noise in the 3/4 tones with versus without various adjustments. That sailed straight through like s..t through a goose - and he invited me to go to the 38th floor for a camera permit. By then I was finished the job so no permit needed, but for those locals wanting to photograph on the grounds of the TD Centre with an expensive P&S - go to the 38th for a permit first - will save harassment.
OK back to the pictures. Definite improvement at ISO 200 - the shots with HTP disabled definitely display less noise. I also did a bunch, HTP disabled, at ISO in the range of 400~640 and I'm less impressed. Noise readings in Noise Ninja are in the 14~23 range (mainly high frequency Luminosity noise), most visible in skies and skin tones. I had expected better, and wonder whether this is typical for this camera, or I should take it back to Canon for testing.