DigitalCameraReview.com
Canon PowerShot SD790 IS Review
by AKAJohnDoe -  8/3/2008

The Canon PowerShot SD790 IS is a 10 megapixel point-and-shoot camera with a 3x optical zoom, image stabilization, and a 3-inch LCD. At first glance, not much in the specifications to distinguish it from the pack.

Canon PowerShot SD790 IS


But beyond this straightforward specs sheet, the SD790 does have some features implemented in highly usable ways and feels well-built.

FEATURES OVERVIEW
FORM, FIT, AND FEEL
PERFORMANCE
IMAGE QUALITY
CONCLUSIONS
SPECIFICATIONS

FEATURES OVERVIEW
As mentioned, the Canon SD790 IS is a 10 megapixel camera. It uses a rechargeable battery and accepts SD/SDHC memory cards. There is no internal memory, so shooting may not be done without a memory card. The camera as tested came in a silver finish and felt robust, almost heavy for the size. In fact, at 5.47 ounces it is a bit heavy for its size.

The lens is a 3x optical zoom ranging from 6.2-18.6mm, which is a fairly conservative 35-105mm in 35mm terms. The aperture is better than average, though, ranging from f/2.8 at the wide end to f/4.9 at telephoto. Digital zoom is also available via the menus up to 4x (for a combined 12x range with the optical). Normal shutter speeds range from 1/60 to 1/1500 seconds, although means are provided for time exposures up to 15 seconds. Shutter speeds available depend upon the shooting mode selected.

The Canon SD790 IS provides the versatile shooting modes we have all come to expect. The mode menus are initially selected via a three position slider switch (Movie, Scene, Camera) and then by spinning the control dial. The following options are available in Camera mode:

Twelve scene presets are accessible via the Scene mode position:

Finally, the SD790 provides the following setting options in Movie mode:

For a detailed listing of specifications and features, please refer to the specifications table found at the bottom of the review.


FORM, FIT, AND FEEL

Styling and Build Quality
The Canon PowerShot SD790 IS is sturdily constructed in plastic with metal accents.

Canon PowerShot SD790 IS

When turned off the lens is flush with the face of the camera. The LCD is also flush with the back and is fixed; it does not rotate or pivot.

Ergonomics and Interface
The control layout is mostly intuitive, although not always the best for handling and usage.

The top has the on/off power button, the shutter release, and a toggle ring surrounding the shutter release that operates the zoom function. On the edge, between the top and the back, is a three position mode slider switch, used to select Movie, Scene, or Camera mode. (Arguably, this should have been a four position switch with the addition of Playback mode.)

Canon PowerShot SD790 IS

The back is primarily covered by the large LCD screen, of course, but the buttons on the back are slightly different than I have seen before on a digital point-and-shoot. There are two buttons at the top and two at the bottom that remind me of the keys on some cell phones.

In between these there is a control dial, familiar to those who have used other Canon cameras, but far more free-wheeling than those. It is too easy to change a setting, or to spin past a setting, without meaning to. A set of raised bumps, presumably intended as a thumb rest, sits between the buttons and the LCD; however, the natural landing spot for the thumb is on top of the two top cell-phone-like buttons. Care must be taken to not inadvertently press them.

Like most new Canon compacts, there is a menu option to change the function of the Print/Share button, and I recommend that you do so.

The bottom two cell-phone-like buttons are used to modify the display and to invoke the menus. These are all fairly normal and straightforward functions.

The control dial in the center has four functions around the perimeter, like a joystick, a center Function Set button, and the outer spinning wheel used for scrolling through options. Used together they make a highly efficient handling system. As noted, I would like to see a bit more resistance on the control dial's spinning, though. The four functions of the joystick/control dial are, clockwise from the top: ISO, Flash, Erase/Continuous/Self Timer, and Macro/Infinity

The menu system on the SD790 is nothing new. It is a standard tabbed interface with text and drop-down selections. Many of the more frequently used functions can also be accessed by pressing the Function Set button in the center of the Control Dial.

Display/Viewfinder
The LCD measures 3.0 inches diagonally. There is no optical viewfinder, so composition is done via the LCD only; however, unlike many other LCD-only cameras, the SD790 IS screen is quite visible in almost any light.

In another pleasant surprise, the SD790's LCD color reproduction is superb, although perhaps with a bit more punch than the actual image.

It is possible to zoom in and out on images and move about the images when reviewing in Playback mode.


PERFORMANCE

Timings and Shutter Lag
As would be expected there is some minor delay between the AF acquisition and the shutter release; however, the SD790 IS performs better than most compact digital cameras in this regard. Measured lag is approximately 0.04 seconds with prefocus, and 0.42 seconds without prefocus.

There is a continuous drive setting for taking pictures of moving subject or in other situations where back-to-back shooting is required. Images are taken sequentially at approximately 1.5 frames per second, or 10 full-res frames in 6.64 seconds. Shooting can continue at this rate until your memory card fills up or the battery looses charge.

Start-up to first shot times with the SD790 are good, coming in around 1.7 seconds.

Lens and Zoom
The lens is a 3x optical zoom ranging from 6.2-18.6mm – a fairly conservative 35-105mm in 35mm terms. Coupled with the 4x digital zoom, up to a 12x zoom range is possible. The lens is a good optical design and produces sharp images with good contrast.

Auto Focus
The auto focus in this camera was adequate if not superb, but even in macro mode it worked acceptably. In macro mode, using a tripod would help more. The SD790 did seem to hunt a bit more than I am used to and did not always settle on the subject I had in mind.

As with most cameras, AF (and exposure) can be locked by a half-pres of the shutter button.

Flash
The SD790's flash seems a bit slower than most as a maximum power discharge takes 9.2 seconds. The average was below 4 seconds, however.

There is no setting for flash compensation.

Image Stabilization
The Canon PowerShot SD790 IS has image stabilization to compensate for shake to minimize blur. This can add a couple of stops to the hand holding abilities of a camera. There are four settings for the optical stabilizer: Off, Continuous, Shoot Only (that is, single shot), and a Panning mode for capturing sharp shots of subjects moving across a frame.

Battery Life
My opinion has not changed: spare batteries simply make good sense. I did have to charge the battery and the recharge cycle took about 2 hours to complete. Still, the battery takes and holds a charge for quite awhile – for over 330 images or for 7 hours of playback time according to Canon's literature.


IMAGE QUALITY
I was generally pleased with the overall quality of the images produced by the SD790 IS. The colors were accurate and detailed, the images sharp, and the exposure usually correct.

Canon PowerShot SD790 IS

While noise can be seen as low as ISO 200, the images up through ISO 400, and even at ISO 800, were quite good; above that (ISO 1600) the image quality significantly deteriorated.

Exposure, Processing, and Color
The camera has digital assist in both the zoom and macro modes. While this does extend the abilities of the SD790, it is at the expense of image quality. I took a number of images in both modes and will reference some of them presently. The digital zoom is really a necessary feature given the rather short optics of the telephoto.

Canon PowerShot SD790 IS

These images of St. John's Wort are simple close-ups taken without digital assist. For reference, all of the images in this review were taken hand-held, without a tripod.

Canon PowerShot SD790 IS

With this camera, as with other cameras with such settings, and particularly with a subject such as flowers, I would be mighty tempted to use the Vivid Mode. See for yourself the difference these settings can make. These studio shots were taken with the SD790's the Neutral, Positive Film, Vivid settings.

Canon PowerShot SD790 IS
Neutral

Canon PowerShot SD790 IS
Positive Film

Canon PowerShot SD790 IS
Vivid

I particularly like the Vivid effect, being a slide film user when not shooting digitally. Used properly, it has great "wow factor" potential. Additionally, using the in-camera special effects can often reduce or eliminate post-processing in a computer.

White Balance
White balance is user-selectable via the menus. The possible selections include Auto, Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent-H, and Custom.

I found the Daylight and Cloudy settings to be accurate on this camera. Not surprisingly, though, incandescent light proved to be more a challenge for the Auto setting. For comparative purposes with other reviews, we include an image taken with the Auto white balance setting under 3200K incandescent light.

Canon PowerShot SD790 IS
Auto White Balance, 3200K incandescent light

Lens Faults
At the wide-angle end pf the SD790's not-so-wide lens, there is still some barrel distortion. If a bit disappointing, it is not significantly different than other cameras of this class. Otherwise, Canon's optic performed in keeping with other moderate-range lenses seen in competitive cameras.

Sensitivity and Noise
It is a given that noise increases with a corresponding increase in ISO speed. It happens with film; it happens with digital. Commonly, there are also color shifts apparent when comparing similar pictures taken at different ISO settings. It is for these reasons that a set of pictures is taken at each ISO setting with each camera tested.

The Canon SD790 IS permits sensitivity settings from ISO 80 to ISO 1600 at full resolution, with a ISO 3200 setting taking shots at a lower resolution. An Auto setting is also available.

I find the results quite satisfactory at each of the settings given the purpose of each setting, although quality was noticeably degraded at ISO 1600. There is a slightly noticeable shift in noise at ISO 200, which expectedly progresses as sensitivity is increased to ISO 1600.

Canon PowerShot SD790 IS
ISO 80
Canon PowerShot SD790 IS
ISO 80, 100% crop
Canon PowerShot SD790 IS
ISO 100
Canon PowerShot SD790 IS
ISO 100, 100% crop
Canon PowerShot SD790 IS
ISO 200
Canon PowerShot SD790 IS
ISO 200, 100% crop
Canon PowerShot SD790 IS
ISO 400
Canon PowerShot SD790 IS
ISO 400, 100% crop
Canon PowerShot SD790 IS
ISO 800
Canon PowerShot SD790 IS
ISO 800, 100% crop
Canon PowerShot SD790 IS
ISO 1600
Canon PowerShot SD790 IS
ISO 1600, 100% crop

All in all, the performance is very good up through ISO 200. Shifting up to ISO 400 or even ISO 800 still shows fair detail. Personally, I would use ISO 80 up through ISO 400 or even ISO 800 interchangeably depending on available light. At ISO 800 the noise, or loss of detail, predictably increases. Still, quite ISO 800 is usable for most applications. By ISO 1600 most fine detail is gone, but in low light without flash it may still be the only viable option. Use flash when you can instead of ISO 1600.

Additional Sample Images
Sometimes we simply cannot get physically closer to our subject. This is when the zoom comes in handy. I prefer not to use digital zoom, as I do not like the quality degradation it introduces, but that is an option when the situation warrants. These images were taken with digital zoom.

Canon PowerShot SD790 IS

Canon PowerShot SD790 IS

Canon PowerShot SD790 IS

These images were taken as close-ups, without employing the digital macro settings.

Canon PowerShot SD790 IS

Canon PowerShot SD790 IS

Canon PowerShot SD790 IS

Compare with those images with these images that were taken with the digital macro settings.

Canon PowerShot SD790 IS

Canon PowerShot SD790 IS

I believe that a faster ISO, a tripod, flash, or a combination would be good choices when using the digital macro settings on this camera. However, a higher ISO is only going to exacerbate the noise already introduced by the digital macro setting.

One of the more common uses for small cameras such as this Digital ELPH is the portrait. Often when one wants to capture an image of someone, it is desirable to blur the background (and/or foreground), limiting depth of field. The Canon SD790 IS proves itself completely capable of achieving this effect as can be seen in this image.

Canon PowerShot SD790 IS


CONCLUSIONS
The images produced by the Canon PowerShot SD790 IS are generally quite good. Still, I ended up with fewer keepers than normal due to focus issues and noise concerns with the SD790's familiar 10 megapixel sensor.

Some will enjoy the SD790's nonstandard ergonomics, but the unusual control layout may detract from overall usability of this camera for many. Some of the buttons seem superfluous and the control dial spins far too easily. I have used the control dials for years on the Canon SLRs and DSLRs and prefer the sureness and purposefulness of them; unfortunately, the SD790's dial gives a much more disconnected feel that can make the camera hard to manage at times.


Overall, the SD790 is a logical upgrade in terms of resolution to Canon's Digital Elph line, and a great screen impresses. But with fairly conventional specs all around and a few rough edges, the SD790 doesn't always live up to expectations.

Pros:

Cons:


SPECIFICATIONS: Canon PowerShot SD790 IS

Sensor 10.0 megapixel, 1/2.3" CCD
Lens/Zoom 3x (35-105mm) zoom lens, f/2.8-4.9
LCD/Viewfinder 3.0", 230K-pixel PureColor II LCD
Sensitivity ISO 80-1600
Shutter Speed 15-1/1600 seconds
Shooting Modes Auto, Manual, Stitch Assist, Digital Macro, Color Accent, Color Swap
Scene Presets Portrait, Night Snapshot, Kids and Pets, Indoor, Sunset, Foliage, Snow, Beach, Fireworks, Aquarium, High Sensitivity
White Balance Settings Auto, Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H, Manual
Metering Modes Evaluative, Center, Spot
Focus Modes AiAF, Spot AF (Center or Face Detect and Track)
Drive Modes Normal, Continuous, Self Timer
Flash Modes Auto, Forced On, Forced Off, Slow Sync, Red-Eye Reduction
Self Timer Settings
10 seconds, 2 seconds, Off
Memory Formats SD, SDHC, MMC
Internal Memory
None
File Formats JPEG, AVI
Max. Image Size 3648x2736
Max. Video Size
640x480, 30 fps
Zoom During Video Not Specified
Battery Rechargeable Lithium-Ion
Connections USB 2.0, AV output
Additional Features Face Detection, Motion Detection, Optical Image Stabilization, DIGIC III Processor