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Canon PowerShot SD940 IS Review
by Andy Stanton -  9/30/2009

When I first set eyes on the Canon PowerShot SD940 IS (also known as the IXUS 120 IS), one of Canon's newest Powershot ELPH cameras, I asked myself, "Haven't I seen this before?" In fact, it looks almost identical to the PowerShot SD780 IS, released this past February and reviewed by this website in March. The similarity isn't a bad thing, considering that the SD780 IS was awarded an "Editor's Choice."

Canon PowerShot SD940 IS


On closer inspection there are some differences. The most obvious is that the newer camera lacks the optical viewfinder of the SD780 IS. It can be argued that this is no great loss though, as that viewfinder was tiny and often difficult to use. There are other, more subtle differences as well. The newer camera has a wider angle lens and longer optical zoom, 28-112mm (35mm equivalent) compared to 33-100mm in the older camera, and a larger LCD - 2.7 inches compared to 2.5 inches.

The SD940 IS also has a wider maximum aperture. Another difference becomes evident when you pick up the camera. The SD940 IS is very light in weight, only 120 grams, about 40 grams lighter than the previous camera. In fact, it's one of the lightest cameras available today. So the SD940 IS creates a very positive first impression. But does it live up to the reputation of its award-winning predecessor? Let's find out.


BUILD AND DESIGN
In addition to being a very lightweight camera, the SD940 IS is very small - only 3.5 inches wide, 2.2 inches high and 0.8 inches thick. It's so small it can easily be carried in any pocket or purse. But its small size and light weight do not mean it's a shoddily built camera - far from it.

Canon PowerShot SD940 IS

Its body is mostly metal and it has a very solid feel, though the covers to its HDMI/USB port and battery/memory card compartment are plastic and should be opened and closed with care. There's a sturdy metal tripod mount in roughly the center of the camera's bottom. The camera comes in four colors - light blue, silver, brown, and black, the color of the camera I reviewed.

Ergonomics and Controls
Despite its small size, the SD940 IS is easy to hold. The front of the camera is largely metal, with a slightly rough surface, providing a good place to put your fingers while your thumb grips the plastic port cover located at the top right, rear of the camera.

Canon PowerShot SD940 IS

While I could shoot with one hand I felt more comfortable using my left hand to steady the camera. The front of the camera contains the lens, an auto focus assist lamp and a thin flash. I had to be careful when I used the flash so as not to block it with the fingers of my left hand.

The top of the camera contains a relatively large shutter button which incorporates the zoom control. Next to it is a tiny, recessed power button which I sometimes had to push repeatedly to get to work. Next to that are pinhole openings for the microphone and speaker.

Canon PowerShot SD940 IS

The rear of the camera contains Canon's usual four-way circular control panel. Pressing the up directional button lets you change exposure compensation (in program mode only), right accesses the flash controls, down enables activation of the self-timer (and deletes the picture in photo review mode), and left adjusts the distance from macro to normal and infinity (in program mode only).

Canon PowerShot SD940 IS

In the center is the function/set button, which accepts menu selections as well as gives you access to the function shortcut menu. Beneath the control panel are a button for displaying information on the LCD screen and another button activating the main menu. At the top left of the panel is a photo review button, next to which is a three-way selector for auto, program and movie modes. Most of the controls are recessed and were sometimes difficult for me to use, especially the circular control panel.

Canon provides a small "Getting Started" guide, which is enough to cover the basic functions of the camera. A more detailed User Guide is found on the accompanying CD.

Menus and Modes
The SD940 IS uses Canon's traditional combination of two different menu systems. The main menu is accessed by the dedicated menu button and contains two columns - one for shooting settings and the other for basic camera settings. These are settings that won't be changed often. The shortcut menu system is activated by pressing the function/set button, which brings up a menu that contains settings that are changed more frequently, although most of the settings are only accessible in program or movie mode. Menu choices are accompanied by a brief, helpful explanation.

As mentioned earlier, the rear of the SD940 IS has a selector switch which activates three shooting modes, as follows:

Display/Viewfinder
The SD940 IS has a 2.7 inch diameter LCD with 230,000 dots of resolution. It can be adjusted to five brightness levels. I found it to work well in most shooting situations. There is no viewfinder but, considering the high quality of the screen, a viewfinder isn't necessarily needed.

PERFORMANCE
This is one quick little camera. I was able to carry it comfortably in my pocket, confident that if I discovered something worth shooting, I could quickly take it out and get the shot. Its wide angle lens gave me flexibility in taking close-up shots, while its 4x optical zoom was adequate for slightly longer range shooting situations.

Shooting Performance
The SD940 IS starts up almost instantaneously. Times for shutter lag and auto focus acquisition are short and feel even shorter. I was able fire off numerous shots about every two seconds with about an extra two or three seconds added when the flash was used. At no time did the camera pause to write to the memory card. The SD940 is no champ when it comes to continuous shooting, though, consistent with Canon's other small cameras, but it can shoot continuously until the memory card is full. Shut down time is very quick.

Shutter Lag (press-to-capture, pre-focused)

Camera Time (seconds)
Panasonic Lumix DMC-FP8 0.01
Sony Cyber-shot DSC-T700 0.02
Canon PowerShot SD940 IS 0.03
Nikon Coolpix S620 0.07

AF Acquisition (press-to-capture, no pre-focus)

Camera Time (seconds)
Sony Cyber-shot DSC-T700 0.23
Panasonic Lumix DMC-FP8 0.27
Nikon Coolpix S620 0.28
Canon PowerShot SD940 IS 0.34

Continuous Shooting

Camera Frames Framerate*
Panasonic Lumix DMC-FP8 3
2.2 fps
Nikon Coolpix S620 3 1.7 fps
Sony Cyber-shot DSC-T700 10
1.6 fps
Canon PowerShot SD940 IS
0.89 fps

* Note: Continuous shooting framerates are based on the camera's fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). "Frames" notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

The SD940 IS has a tiny flash but it works surprisingly well. Canon claims it can cover 13 feet at wide angle and 6.6 feet at maximum telephoto and this was generally supported by my own experience. The flash can be set to auto, red-eye reduction (using the auto focus assist lamp), flash on, flash off, and slow synchro, which slows shutter speed to brighten the background. Canon says that the flash has a recharging time of less than 10 seconds, though I never had to wait close to that length of time for the flash to recharge.

The SD940 IS uses a rechargeable lithium-ion battery which Canon rates for 220 shots. I was able to get only 170 shots, but I also spent considerable time perusing the menus. Taking movies and using the flash will reduce the battery life. If you're going to be shooting all day, it would be a good idea to bring along an extra battery or two.

Lens Performance
The SD940 IS has a 4x optical zoom lens (28-112mm), which is slightly longer than you'll find in cameras of similar size and weight. Further, it has a fairly wide maximum aperture of f/2.8 (wide) and f/5.9 (telephoto), which helps in low light shooting. The camera's low light shooting ability is also aided by Canon's excellent optical image stabilization system, which allows you to shoot at an aperture two to three stops lower than would otherwise be possible. It also helps to reduce the blurring effect of camera shake when the lens is at maximum zoom. I noticed very few blurry photos among the approximately 250 I took with the SD940 IS. I was pleased with the sharpness of the lens.

Canon PowerShot SD940 IS

I observed minor barrel distortion at wide angle and minor pincushion distortion at maximum zoom.

Canon PowerShot SD940 IS
Wide Angle

Canon PowerShot SD940 IS
Telephoto

I noticed some chromatic aberration (fringing) in high contrast situations when the photo was blown up, but it shouldn't be a problem at normal resolution.

Canon PowerShot SD940 IS

Video Quality
The SD940 IS takes impressive HD movies. Optical zoom cannot be used, but I did achieve decent results with digital zoom. The camera's microphone is very sensitive to wind and other noises. Hint: don't chew gum while taking a video.

Image Quality
Canon cameras consistently exhibit pleasing colors, especially blues, and the SD940 IS is no exception. I shot mostly in auto mode, but did some experimenting with various "my colors" options. I particularly liked the lush colors produced by Canon's "positive film" mode.

Canon PowerShot SD940 IS
Standard

Canon PowerShot SD940 IS
Vivid

Canon PowerShot SD940 IS
Neutral

Canon PowerShot SD940 IS
Positive Film

I was intrigued by Canon's i-Contrast feature and found that, in high contrast scenes, it did increase the visibility of details that would otherwise be obscured.

Canon PowerShot SD940 IS
i-Contrast Off

Canon PowerShot SD940 IS
i-Contrast On

The SD940 IS includes several options for white balance - auto, daylight, cloudy, tungsten, fluorescent, high fluorescent, and custom. Auto white balance generally works well, though it produces a slight yellowish tinge under incandescent light. This can easily be corrected by setting white balance to tungsten (in program or movie modes only).

Canon PowerShot SD940 IS
Auto White Balance, 3200k incandescent light

Canon point-and-shoot cameras used to be relatively noisy at higher ISO settings, though we found that the photos they produced retained more detail than those of the competition. That's not the case here, as images at higher ISOs, though not terribly noisy, are quite soft. While the SD940 IS produces nice, clean images at 80 and 100 ISO, some softness is evident at 200 ISO and it increases significantly at 400 ISO.

Canon PowerShot SD940 IS
ISO 80
Canon PowerShot SD940 IS
ISO 80, 100% crop
Canon PowerShot SD940 IS
ISO 100
Canon PowerShot SD940 IS
ISO 100, 100% crop
Canon PowerShot SD940 IS
ISO 200
Canon PowerShot SD940 IS
ISO 200, 100% crop
Canon PowerShot SD940 IS
ISO 400
Canon PowerShot SD940 IS
ISO 400, 100% crop
Canon PowerShot SD940 IS
ISO 800
Canon PowerShot SD940 IS
ISO 800, 100% crop
Canon PowerShot SD940 IS
ISO 1600
Canon PowerShot SD940 IS
ISO 1600, 100% crop

At 800 and 1600 ISO, the images get even softer, though they retain significant color. The SD940 IS also has a scene mode for shots at 3200 ISO, but the image is very soft and noisy and shouldn't be used except in emergencies. While the images are probably better overall than those of the previous version of the camera, it's evident that the SD940 IS does its best work at 200 ISO and lower.

Additional Sample Images
Canon PowerShot SD940 IS Canon PowerShot SD940 IS
Canon PowerShot SD940 IS Canon PowerShot SD940 IS

CONCLUSIONS

The SD940 IS is a pleasure to use. It has excellent build quality and is very quick and responsive. Its small size makes it convenient to carry everywhere you go, so you're always ready to take advantage of an available photo opportunity.


It takes very good pictures in good light and has a small but effective flash. Even though it does not allow direct control over aperture and shutter speed, it has many options available so you can tailor the picture to your satisfaction. Its only significant downsides are that it takes soft photos at high ISOs and exhibits some chromatic aberration.

Pros:

Cons: