http://www.bhphotovideo.com/c/find/newsLetter/PowerShot-G11-S90.jsp
Canon PowerShot G11
Ever since the introduction of the original 3.3Mp PowerShot G1 way back in the year 2000, most every succeeding G-series digicam has boasted an ever-increasing pixel count. The G10 capped them all at 14.7Mp. With the introduction of the Canon PowerShot G11, Canon's engineers have taken a step backwards in a sense by turning to a new 10Mp imaging sensor, which contains about a third fewer – albeit larger - pixels than its predecessor, the G10. So the $64 question is- 'How does this drastic dose of pixel-shrinkage affect image quality?' The answer is 'quite well, and thank you for asking'.
It's no big secret the higher-resolution sensors found in many digicams fall short of their lower-res siblings and predecessors. You can subdivide an imaging sensor just so far before the benefits of higher pixel-counts start compromising the dynamic range of the image in the form of blown highlights, murky shadows, and blotchy tonal transitions. Based on comparisons between a G10 and an early production model of the G11, Canon's engineers seem to have taken a good change of course.
As for overall image quality, the image files produced by our test G11 were equal to - and in some circumstances better than - image files produce by the G10. This is noteworthy considering the files produced by the G11 are considerably smaller (about 28.6Mb) compared to the files produced by the G10 (about 41.8Mb). (So much for the more-is-better school of thought… eh Kemosabe?)
The G11 strongly resembles its predecessor, the G10, and thankfully retains the G10's 'real camera' analog control dials for switching exposure modes, ISO sensitivity, and exposure compensation. The biggest exterior difference is the G11's 2.7", 461,000-dot swivel-mounted LCD. If you've used a swivel-LCD in the past, you'd note its absence when trying to shoot from difficult angles with the G10. Not so with the G11. The cost of this convenience is about 9/10th of a millimeter of additional padding on the camera's profile, but such is life. The swivel feature also allows you to face the LCD inward to protect the LCD surface when it's not in use.
Like the G10, the G11 sports an honest-to-gosh optical viewfinder which, peephole-ish as it may be, is a welcome alternative to the camera's LCD when shooting under brighter lighting conditions.
The lens, the same 6.1~30.5/f2.8-4.5 5x (28~140mm equivalent) zoom lens used on the G10, does a fine job capturing sharp stills (JPEG and/or RAW) and video despite a bit of pin-cushion distortion common to most zoom lenses in this genre of cameras, most noticeably at the wide end of the zoom range.
One of the niceties of the G-series PowerShot cameras has been the hot-shoe, which enables the use of all of Canon's Speedlite flashes and compatible third-party flashes. The hot-shoe also facilitates the use of optical and radio transmitters for triggering studio strobes. And if you plan on using the G11 in studio environments, you'll be pleased to know the G11 has a top flash sync of 1/2000th compared to the G10's already-fast top sync speed of 1/500th.
Other improvements found in the G11 include an HDMI output port for playing back still and video on your TV or computer monitor, higher low-light sensitivity, and a Dual Anti-Noise System, that along with the G11's DIGIC 4 image processor, allows for noticeably better low-light imaging at ISO levels up to 3200 (ditto for the PowerShot S90). While image files from most cameras in the point-and-shoot arena start falling apart once you get to around ISO 400 (regardless of manufacturer's claims), the images produced by both the G11 and S90 in the ISO 400-800 range proved to be impressive with reasonable noise levels, and even at 1600 and 3200, both the G11 and S90 produced very usable image files.
Canon PowerShot S90
The PowerShot S90 can easily be described as a trimmed-down, sportier body… and then some. The S90 includes many of the key features found in the G11 including the same 10Mp imaging sensor, optical image stabilization, JPEG and/or RAW capture abilities, Blink Detection, advanced Face Detection (with Self Timer), and Intelligent Contrast Correction.
Compactness aside, the big draw for the S90 is its 6~22.5mm zoom lens (28~105mm equivalent) that opens up to an impressive f2, making it particularly attractive for capturing stealthy, sharp, flash-free images under the lowest of lighting conditions. Physically, the S90 is half the weight (6.17 oz vs.12.5 oz) and about a third smaller (4.41 x 3 x 1.9" vs. 3.94 x 2.3 x 1.22") than the G11. If pocket-ability and/or stealthy-ness are deciding factors, the S90 is the path to follow.
As a trade-off for lopping off the analog control dials that adorn the top deck of the G11, the S90 has a handy control ring surrounding the camera lens that allows you to adjust the exposure, ISO, zoom, white balance, and manual focus by simply choosing the desired mode and rotating the control ring. Adjustments can be viewed in real-time on the camera's 3", 461,000-dot LCD.
G11 S90 G11 S90
While both cameras proved to be worth their oats under low light conditions, the extra stop of light availed by the S90 made for some very sharp wide-aperture imaging under both bright and low-lighting conditions. Hand-held street-shooting on city streets is akin to snap-shooting under daylight conditions, and even wide open, the S90's lens performs quite admirably.
The fast f/2 maximum aperture on the S90 also makes for strong bright-light imaging. In addition to quicker focusing and metering performance afforded by lens' wider aperture, selective focusing is easier to achieve in both the wide and long end of the zoom lens.
Even wide open at f2 and at ISO levels upward of 800 and beyond, the S90 delivers surprisingly clean image files
ISO Comparisons
Canon PowerShot G11 / S90 Canon PowerShot G10 ISO 80
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200