Source: http://gizmodo.com/5552422/canon-powershot-sd4000-is-review-no-more-noisy-nights
If you already own a DSLR, you probably don't think twice about snapping shots in low-light conditions. But as most point-and-shoot camera owners can tell you, when the sun goes down, shots from compact cameras tend to pick up noise and blur, fast. Some of the highest-end point-and-shoots, like the Canon S90, have risen to the challenge and adopted bigger image sensors for better low-light shots. But, as high-end compact cameras, they're expensive.
The PowerShot SD4000 IS is designed and priced more for the masses, a $350—not quite cheap but far from expensive—camera that shoots respectably in the dark.
The Skinny
The SD4000 is a nice looking, and nice feeling, camera. It's skinny and asymmetrical, and its tapered edges make it an easy fit even in tiny pants.
While the sensor has been beefed up, the SD4000's controls remain simple. The top has a switch for changing modes and a shutter button ringed by a zoom lever; the back has a click wheel with a function button in the middle and two large buttons for entering the menu and playback mode. On one hand it's nice that the handsome camera isn't cluttered up by a bunch of extraneous buttons, but sometimes it feels like it takes one or two too many presses to get to a desired function.
The controls do offer a wide selection of different modes and effects, like foliage mode for shooting plants, smart shutter mode for triggering snapshots when the subject smiles (or, weirdly, when they wink), and a miniature effect for approximating tilt-shift photography.
To those who despise cutesy shooting modes, don't worry, the SD4000 still offers program, aperture, and shutter speed modes.
But what makes the SD4000 a gem of a camera is that, even if you don't really care about any esoteric shooting modes, you can still just pick it up and take great photos. Especially at night.
Night Moves
The SD4000 is the most advanced Digital ELPH to date, with a backlit 10 megapixel CMOS sensor and wide f/2.0 aperture. Sensors and apertures are easy to learn about, but if you just want the Cliffs Notes version, an f/2.0 aperture basically means that the light-allowing hole in the SD4000 can get a little bigger than that of most point-and-shoots, while the backlit CMOS means that the image sensor grabbing light through the aperture is wired from behind, blocking less light. On paper, all of this means that the SD4000 should take clean, noise-free low-light shots
And it does. Nighttime shots were impressive across the board, with the SD4000 kicking out some strong, low-noise night shots that generally held their own with those of the reigning point-and-shoot champ, the Canon S90. Up to ISO 800, shots showed very little noise. Shots with ISO 1600—and even in some cases 3200—still looked fine for the most part. Here's a detail of a shot from both the SD4000 and S90 at ISO 1600.
One annoyance for more advanced photographers: the camera tended to rely on its wide F2 aperture in low-light situations, and without a full manual mode that sometimes meant being stuck with a shallow depth of field and a blurry background. But that's only a minor quibble, and many will like the effect; overall, the new sensor and lens make an appreciable difference for low-light shooting. The built-in optical image stabilization system (that's the "IS" in the product's name) helps counteract those shaky hands, and a maximum shutter speed of 16 seconds will help you get that long-exposure city-street-with-trailing-tail-lights shot.
Here are some more low-light pictures from the SD4000:
The beefed up lens and sensor also make for nicer nighttime video—here's a 1280 x 720, 30fps clip:
Daytime shooting isn't shabby by any means, either, but it doesn't see as much as improvement from the new sensor as night shooting does—in general, the image quality of shots in bright environments isn't too different from those of other cameras in its class, which is to say, pretty good!
The Photography Blog has a super-detailed breakdown of SD4000 shot quality in all scenarios, if you're so inclined.
High Speed
Aside from the strong low-light performance, the PowerShot SD4000 stands out for its high speed shooting—snapping up to 8.4 frames per second in burst mode (though at a sub-cellphone 2.5 megapixels) and shooting 240fps video in Super Slow Motion video mode (albeit at a super crummy 320 x 240 resolution). Such videos don't look great, but it's a fun feature regardless, allowing you to do stuff like check out what squirrels are actually up to or assemble a personal highlight reel that makes any lay-up look several times more impressive:
Too Low a Ceiling?
For a casual photographer—someone who wants to have a camera on hand without constantly being reminded they're carrying one around; someone who's looking for higher quality shots at night without needing to take full control of their composition—the Canon PowerShot SD4000 IS is a great camera. But with Canon S90 prices creeping lower toward the SD4000's $350 price point, blossoming photographers looking for a more fully-featured (though less pocketable) point-and-shoot to grow into might be better off making that leap. If you're on the fence, here's a quick rundown of some points to consider for each.
The Canon S90 might be better if...
• you want to get into photography and want to take great pictures
• you don't necessarily know how to use a full manual mode, but would like to know it's there
• video is a bonus, not a priority (S90 only shoots standard def)
• you think to throw your point-and-shoot in a bag or purse before a jeans pocket
The Canon SD4000 might be better if...
• you want to take great pictures but aren't too concerned with how they get great
• you're your group of friends' designated photo-taker when you go out at night
• you crave that HD video distinction
• you wear a lot of Spandex
