Chuck Westfall – One of Canon’s Guru’s has been asked on Digital Journalist:
I have a pair of questions concerning point and shoot cameras: If a user decreases the pixel count on a Canon PowerShot G9 from 12MP to 6-8MP does image quality improve at higher ISO settings and in low-light situations? Does decreasing the pixel count essentially create a bigger sensor with fewer pixels, such as is found on a Fujifilm FinePix F30 or F31fd?
There is no significant improvement in noise levels at any ISO setting when shooting in-camera JPEGs at the 8MP “M1″ or 5MP “M2″ settings with the PowerShot G9, compared to shooting full-resolution 12MP images. However, if you are interested in extracting the maximum image quality the G9 can produce, I would suggest using the camera’s RAW mode and applying noise reduction during post-processing in your personal computer. Canon’s RAW Image Task software, supplied at no extra charge with the G9, has an Adaptive Noise Control slider that does a good job at reducing noise while retaining a high level of fine detail. The resulting images, especially when printed, tend to be sharper with less noise than those produced by most other point-and-shoot digital cameras regardless of resolution or pixel size at equivalent ISO speed settings.
LifeSpy Well there you have it!
Also see the post on noise reduction for Lightroom and ACR
Tech Tips – The Digital Journalist
It’s been commented on several reviews that the G9 is a little noisy due to having so many pixels on a small sensor (less and bigger is better for cutting noise) but its is not as bad as every one makes out, a lot of reviews seem to want the ultimate perfect camera and now! They are getting frustrated at the slow speed of technology and overtly nit picking because the camera manufactures put in features that in some ways is a step backwards.
To reduce noise the exposure is an important aspect and is best moving the exposure to the right (on the histogram) and so it is not touching the Left hand edge. Noise is caused by light hitting the pixel but not being enough to measure a bit like putting a bucket out to catch rain, it may be wet inside from a light shower but can be hard to measure so deliberately adding more exposure is like adding a measured amount of rain so the bucket (pixel) has something to measure
For the G9 at ISO 800, Thomas Niemann (of PTLens fame) has suggested the following settings in ACR Details page: (ACR = Adobe Camera Raw as found in Photoshop CS/Elements and Lightroom)
radius = 0.8
detail = 30
masking = 0
luminance = 80
colour = 100
Source: Luminous Landscape forums
These settings can be saved as a preset in ACR and Adobe Lightroom
There is also Neat Image, Noise Ninja and Noisewear that are specific noise reduction programs and are worth checking out, the pro versions also work with RAW files and Noisewear do a limited but free community edition